Search Results

Search found 344 results on 14 pages for 'pinging'.

Page 12/14 | < Previous Page | 8 9 10 11 12 13 14  | Next Page >

  • Asynchronous URL connection objective C

    - by tweety
    I created an asynchronous URL connection to call a web service using HTTP POST method. after I am pinging the web i set an NSTimerInterval in the completion handler. my problem is when I'm trying to display the time on the view controller it is not doing promptly. I know block is stored in the heap and gets executed later on anytime and probably that's why i'm not getting prompt answer. I was wondering is there any other way to do this? Thanks in advance. my code: __block NSDate *start= [NSDate date]; __block NSDate *end; __block double miliseconds; __block NSTimeInterval time; [NSURLConnection sendAsynchronousRequest:urlRequest queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *error) { if([data length]==0 && error==nil){ end=[NSDate date]; time=[end timeIntervalSinceDate:start]; NSLog(@"Successfully Pinged"); miliseconds = time; // calling a method to display ping time [self label:miliseconds]; } -(void) label:(double) mili{ double miliseconds=mili*1000; self.timeDisplay.text=[NSString stringWithFormat:@"Time: %.3f ms", miliseconds];

    Read the article

  • Socket stops communicating

    - by user1392992
    I'm running python 2.7 code on a Raspberry Pi that receives serial data from an Arduino, processes it, and sends it to a Windows box over a wifi link. The Pi is wired to a Linksys router running in client bridge mode and that router connects over wifi to another Linksys router to which the Windows box is wired. The code in the Pi runs fine for some (apparently) random interval, and then the Pi becomes unreachable from the Windows box. I'm running PUTTY on the the Windows machine to connect to the Pi and when the fail occurs I get a message saying there's been a network error and the Pi is not reachable. Pinging the Pi from the Windows machine works fine until the error, at which time it produces "Reply from 192.168.0.129: Destination host unreachable." The client bridge router to which the Pi is connected remains reachable. I've got the networking code on the Pi wrapped in an exception handler, and when it fails it shows the following: Ethernet problem: Traceback (most recent call last): File "garage.py", line 108, in module s.connect((host, port)) File "/usr/lib/python2.7/socket.py", line 224, in meth return getattr(self._sock,name)(*args) error: [Errno 113] No route to host None The relevant python code looks like: import socket import traceback host = '192.168.0.129' port = 31415 in the setup, and after serial data has been processed: try: bline = strline.encode('utf-8') s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((host, port)) s.send(bline) s.close() except: print "Ethernet problem: " print traceback.print_exc() Where strline contains the processed data. As I said, this runs fine for a few hours more or less before failing. Any ideas? EDIT: When PUTTY fails its error message is :Network Error: Software caused connection abort."

    Read the article

  • Unable to ping local machines by name in Windows 7

    - by aardvarkk
    I'm having a strange (and persistent!) problem with pinging local machines on my network by name. I believe my machine (Windows 7 64-bit) is the only one having this issue. This is over a wireless connection. As an example, consider a device on my network by the name of WDTVLiveHub. It's a Western Digital Live Hub (surprise!). If I go to my router's DHCP Client Table in the browser (my router is a WRT400N), I see this entry: WDTVLiveHub 192.168.1.101 Great. So I try to ping that IP address: ping 192.168.1.101 Pinging 192.168.1.101 with 32 bytes of data: Reply from 192.168.1.101: bytes=32 time=9ms TTL=64 Reply from 192.168.1.101: bytes=32 time=16ms TTL=64 Reply from 192.168.1.101: bytes=32 time=16ms TTL=64 Reply from 192.168.1.101: bytes=32 time=16ms TTL=64 Ping statistics for 192.168.1.101: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 9ms, Maximum = 16ms, Average = 14ms OK, still looking good. Now I try to ping it by name: ping WDTVLiveHub Ping request could not find host WDTVLiveHub. Please check the name and try again. From what I've read, this implies a problem with DNS servers and host name lookups. Interestingly, if I type the following: pathping 192.168.1.101 I get this output: Tracing route to WDTVLIVEHUB [192.168.1.101] over a maximum of 30 hops: 0 Scotty [192.168.1.103] 1 WDTVLIVEHUB [192.168.1.101] Computing statistics for 25 seconds... Source to Here This Node/Link Hop RTT Lost/Sent = Pct Lost/Sent = Pct Address 0 Scotty [192.168.1.103] 1/ 100 = 1% | 1 12ms 1/ 100 = 1% 0/ 100 = 0% WDTVLIVEHUB [192.168.1.101] Trace complete. Scotty is obviously the name of my local machine. So it's able to find the name somehow when I do that approach... ipconfig /all shows the following under DNS servers: DNS Servers . . . . . . . . . . . : 192.168.1.1 ***.***.***.*** ***.***.***.*** Where the * represents the same DNS servers that show up in my router under DNS 1 and DNS 2 through the Internet. For completeness, here's the whole output of ipconfig /all: Windows IP Configuration Host Name . . . . . . . . . . . . : Scotty Primary Dns Suffix . . . . . . . : Node Type . . . . . . . . . . . . : Peer-Peer IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No Wireless LAN adapter Wireless Network Connection: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Dell Wireless 1397 WLAN Mini-Card Physical Address. . . . . . . . . : 0C-EE-E6-D1-07-E8 DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes IPv6 Address. . . . . . . . . . . : 2002:d83a:31e5:1234:5592:398e:8968:43d1(Preferred) Temporary IPv6 Address. . . . . . : 2002:d83a:31e5:1234:ecce:2f79:72a5:5273(Preferred) Link-local IPv6 Address . . . . . : fe80::5592:398e:8968:43d1%26(Preferred) IPv4 Address. . . . . . . . . . . : 192.168.1.103(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.255.0 Lease Obtained. . . . . . . . . . : September-17-12 11:05:57 PM Lease Expires . . . . . . . . . . : September-18-12 11:05:57 PM Default Gateway . . . . . . . . . : fe80::200:ff:fe00:0%26 192.168.1.1 DHCP Server . . . . . . . . . . . : 192.168.1.1 DHCPv6 IAID . . . . . . . . . . . : 537718502 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-12-80-3D-D7-00-26-B9-0D-08-70 DNS Servers . . . . . . . . . . . : 192.168.1.1 ***.***.***.*** ***.***.***.*** NetBIOS over Tcpip. . . . . . . . : Enabled Ethernet adapter VirtualBox Host-Only Network: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : VirtualBox Host-Only Ethernet Adapter Physical Address. . . . . . . . . : 08-00-27-00-98-9A DHCP Enabled. . . . . . . . . . . : Yes Autoconfiguration Enabled . . . . : Yes Link-local IPv6 Address . . . . . : fe80::b48a:916b:c0f:fb29%23(Preferred) Autoconfiguration IPv4 Address. . : 169.254.251.41(Preferred) Subnet Mask . . . . . . . . . . . : 255.255.0.0 Default Gateway . . . . . . . . . : DHCPv6 IAID . . . . . . . . . . . : 570949671 DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-12-80-3D-D7-00-26-B9-0D-08-70 DNS Servers . . . . . . . . . . . : fec0:0:0:ffff::1%1 fec0:0:0:ffff::2%1 fec0:0:0:ffff::3%1 NetBIOS over Tcpip. . . . . . . . : Enabled Tunnel adapter Local Area Connection* 15: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter isatap.{55899375-C31D-4173-A529-4427D63FD28B}: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft ISATAP Adapter #2 Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Tunnel adapter isatap.{64B8F35F-A6AB-4D6B-B1D5-DD95F57B1458}: Media State . . . . . . . . . . . : Media disconnected Connection-specific DNS Suffix . : Description . . . . . . . . . . . : Microsoft ISATAP Adapter #3 Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes Not sure exactly how to diagnose exactly what's going on... but the problem is really frustrating! The biggest problem is that my mapped network drives have to be done by IP, and then any time the router assigns new IP addresses to those devices, all of my network shares break again. Stinks! Would love some assistance on possible solutions. I've tried all of this netsh catalog resetting and that didn't seem to fix anything at all. Would love an explanation of what's going wrong, too, rather than blindly resetting things! Thanks!

    Read the article

  • Nameserver not resolving or domain not pingable [closed]

    - by Ricky
    Sorry, if anyone can think of a better title please change it! I want to host my own websites from home. For testing purposes, I have a virtual machine running a trial version of Windows Server 2008 Enterprise. Note I currently run a VPS and host my own websites but due to a nice speed upgrade on our line I now want to host from home. I have several domains but I wanted to test with one, that is rickyoleary.com. Our ISP does not provide static IP addresses unless we have a business account so I've been looking at no-ip.com. I admit my networking isn't the best, hence this question but I've been bashing my head all day on this one. I created a host name, muffinbubble.no-ip.org which runs on IP: 86.148.124.15. I've setup IIS on the server with a simple test page. I've then forwarded port 80 traffic from the router and from what I can see, it's working. If I access my website (I was unable to link to this for some reason so please copy and paste this) - http://86.148.124.15/ - I see my test page. So the next step was to create my nameservers. This domain is with namecheap.com so I created my nameservers, ns1.rickyoleary.com and ns2.rickyoleary.com. Both these point to the same IP (and yes, that will be changed after testing), the same IP as above: 86.148.124.15. On the server itself I have set up DNS entries as below which I believe to be correct and added rickyoleary.com and www.rickyoleary.com in the host headers (or bindings) in IIS 7.0. If I try and look up my domain, rickyoleary.com it shows ns1.rickyoleary.com and ns2.rickyoleary.com as the nameservers. I then tried to use just-ping.com on my nameserver ns1.rickyoleary.com. I get 100% packets lost, but the correct IP address is returned (I'm guessing the router does not allow pings, but is still accessible...). I get no response when pinging rickyoleary.com. Here's the problems: I cannot ping ns1.rickyoleary.com or ns2.rickyoleary.com from a command prompt. I'm not sure if this is an issue. When I added the nameservers in Windows Server 2008 and clicked 'resolve' a message box displays stating "No such host is known". I cannot ping rickyoleary.com. rickyoleary.com is not showing my test page on my server. Now - please note, I've waited around 6 hours for propagation. From my experience, although you're told to wait 24 - 48 hours, the changes are normally pretty quick so perhaps I'm being impatient or naive to think it should all be working fine until then. I would really appreciate some help here. Thanks.

    Read the article

  • Windows Vista: Networking can only connect "local only"

    - by Damien
    I am attempting to debug a problem on a Windows Vista laptop - not mine! Until just recently (last week or so), it was operating normally for about 4 years :) The problem is that I am having issues connecting to the local network (a basic wireless home router; more later) and the internet (via ADSL). This is both for wired [Broadcom chipset] and wireless [Intel chipset]. I will elaborate further later. To detail the network. I have three other clients (HTC phone, Ubuntu 12.04 desktop [wired] and Ubuntu 10.04 laptop [wireless]), all of whom are able to connect to the network and internet normally. A windows 7 virtual machine running on said desktop connects normally. I have tried two different wireless routers - Netgear DG834G and Netgear DGN3500. The same error mode is common to both. Updating the firmware to the latest on both routers does not help. Overall, it seems safe to say it's localised to the laptop in question. I do not have another Vista client to test with. The specific symptoms are as follows: When "connected", it says "Local Only", and says it cannot connect to the internet. This is true for both wired and wireless. It can get an IP address (192.168.0.5), and the router (192.168.0.1) reports that it can see the device. When I try to ping, I get the following results: ping 192.168.0.1 - (router) all packets lost ping 192.168.0.5 - (laptop's address) OK ping 192.168.0.4 - (desktop) all packets lost Pinging from the desktop to the problematic laptop results in "From 192.168.0.4 icmp_seq=1 Destination Host Unreachable" The most promising "fix" from trawling forums is KB928233 which does not work for me. The problem is persistent across reports (both full shutdown and hibernate) so it appears not to be sleep related. I am not a regular vista user, though I can fumble my way about a bit. Is there any other suggestions as to what I should do? Is there any further information I can provide?

    Read the article

  • Static IPv6 address in Windows unused for outgoing connections

    - by Luc
    I'm running a Windows server and trying to get it to use a static IPv6 address for outgoing connections to other IPv6 hosts (such as Gmail). I need this because Gmail requires a ptr record, and I can't set one for random addresses. The static address is configured on the host, but it also has a temporary privacy address as well as a random address from the router it seems. By default Windows uses the privacy address; it seems this is the expected behavior (and it makes perfect sense for people/users that did not set a static address, but I did!). I've tried disabling the privacy address with: netsh int ipv6 set privacy disabled This indeed gets rid of the privacy address, but I still have the random address that the router assigned. To disable this, it was said I needed to disable "router discovery" using this command: net interface ipv6 set interface 14 routerdiscovery=disabled Upon doing this, all IPv6 connectivity is lost. If I do this while pinging Gmail, it will report "Destination host unreachable" as soon as I enter the command. In the static IPv6 configuration, I did configure the default gateway and prefix length, so I don't see why it's unable to connect. Probably has something to do with the lack of ARP in IPv6 and somehow being unable to resolve the router's MAC, but I wouldn't know how to fix this. Finally I've tried disabling the DHCPv6 lease with these commands: netsh interface ipv6 set interface "IDMZ Team" managedaddress=disabled netsh interface ipv6 set interface "IDMZ Team" otherstateful=disabled Which was to no avail; the host continues to obtain and use the router-assigned IPv6 address. The router is a FritzBox 7340, which shows me all the IPv4 and IPv6 addresses that the host (identified by MAC) utilizes, but I'm unable to change the assigned address. Maybe this could be done over the telnet interface of the router somehow, but again, I wouldn't know how to do this even if it's the way to go. In short, any of the following would probably solve my problem: Change Windows' source address selection behavior. Have Windows not get an address from the router and not generate a privacy address; Have the router hand out a static address and make Windows use that as source address. Recover connectivity after disabling router discovery on Windows. Alternatively I might use some (batch, perl, ...) script to throw away all IPv6 addresses except the desired one, but this feels rather hacky. If it's the only way (or less hacky than another hacky solution), it might be an option though. Thanks!

    Read the article

  • My server freezes within a few hours of logging out. Staying logged in keeps the server running

    - by HappyEngineer
    I have an Ubuntu Godaddy server I use to host mail and webapps. It started having problems a couple months ago. It would lock up and stop responding to anything. I couldn't ssh into it, so I'd have godaddy power cycle the server. I have never seen anything that looked suspicious in the var logs (although I'm no expert at reading them). An fsck turned up no problems. Godaddy replaced the ram, but found no hardware problems. I started logging the output from "top" to a log file and found that even that stops running when the server freezes. Now, here is the crazy part: It got so bad that it would actually go down every few hours, but then it stopped going down. I eventually realized I had left an ssh terminal logged into the machine running top. This seemed unlikely to be a reason, but after the server was up with no problems for a full week (remember, it had been going down after just a few hours), I disconnected from the ssh session. Lo and behold, within a few hours the server froze again! I had them power cycle again and then left another ssh session open with top. It has been going without problems for 8 days now. I told others about this and they hardly believe me. I simply can't imagine what is going on. I don't know what else to try other than to just get a new server and reinstall everything. Does anyone have any ideas about what I can look for to determine what the cause is? Is it possible there's some sort of exploit on the server which only runs if everyone is logged out of the system? EDIT: The power management gone haywire sounds plausible, so I've modified the /boot/grub/menu.lst to boot with acpi=off and apm=off. It appears to have prevented kacpid and kacpid_notify from being in the process list, so I assume I did that right. I've disconnected all my sessions from the server. I'll check later tonight to see if it's still up. If it goes down then I'll try the pinging process idea. EDIT: It went down again. It lasted about a day. I've had them reboot, so now I'll try running "nohup ping -i 5 google.com &" and then disconnect. If it goes down again I'll come back. Hopefully someone will have some more ideas.

    Read the article

  • Archlinux/atheros WLAN configuration troubles

    - by GrinReaper
    I'm trying to config archlinux to use my wireless network adapter. It's quite troublesome. From what I've gathered, it's an atheros network adapter, using the ath5k driver/module... I can't get it to work; any ideas? Here's some of the output from my tinkering: # lspci | grep -i net 00:0a.0 Ethernet controller: nVidia corporation MCP67 Ethernet (reva2) 03:00.0 Ethernet controller: atheros communications inc. AR5001 Wireless Network Adapter (rev01) # lsusb ... Bus 004 Device 003: ID 03f0:17d Hewlett Packard Wireless (Bluetooth + WLAN Interface [Integrated Module] # ping -c 3 www.google.com ping: unknown host www.google.com #ping -c 3 8.8.8.8 ping: network is unreachable # lspci -v 03:00.0 Ethernet controller: atheros communications inc. AR5001 Wireless Network Adapter (rev01) ... Kernel driver in use: ath5k Kernel modules: ath5k # dmesg |grep ath5k registered as phy0 registered led device ath5k: atheros chip found PCI INT A disabled registered led device registered as phy1 # ip addr | sed '/^[0-9]/!d;s/: <.*$//' 1: lo 2: eth1 3: eth0 # ip link set <interface> up/down RNETLINK answers: Operation not possible due to RF-kill Also, is there a way to dump text from command-line to a text file so i can just copy pasta? Sorry, first time using a linux distro... EDIT: So I just tried this: I actually just did this twice. (I can't tell which setting is on/off for my wireless adapter. The lights are blue all the time now.) #rfkill list 0: hp-wifi: wireless lan softblocked: no hardblocked :yes 1: hp-bluetooth: bluetooth softblocked: no hardblocked :yes 3: phy1: wireless lan softblocked: no hardblocked :yes #rfkill list 0: hp-wifi: wireless lan softblocked: no hardblocked :no 1: hp-bluetooth: bluetooth softblocked: no hardblocked no 3: phy1: wireless lan softblocked: no hardblocked :yes 7: hci0: bluetooh 0: hp-wifi: wireless lan softblocked: no hardblocked :no I've dug around some other articles and it seems like ath5k is supposed to be preferable to madwifi, so should i be using madwifi? I'm 99% sure I disabled the hardblock (by turning it ON) but, as shown above, phy1 wireless lan is STILL hardblocked. What gives? Maybe I've made some more fundamental error in a basic config file? EDIT: I've fixed the hardblock. I've tried pinging www.google.com, but to no avail. I get: ping: unknown host www.google.com In the arch wiki: Edit /etc/hosts and add the same HOSTNAME you entered in /etc/rc.conf: 127.0.0.1 archlinux.domain.org localhost.localdomain localhost archlinux To my understanding, hostname is just a user-specified and based on preference(?) My /etc/rc.conf: HOSTNAME="gestalt" My /etc/hosts: 127.0.0.1 localhost.localdomain localhost gestalt but should it be the following? 120.0.0.1 localhost.domain.org localhost.localdomain localhost gestalt

    Read the article

  • Ubuntu Server 10.04 Heavy Network Traffic causes disconnect

    - by K Vaughan
    I'm currently running a headless Ubuntu 10.04 server. Installed is the LAMP stack, Joomla, Virtualbox, phpvirtualbox, webmin and proFTP.. It resolves the IP address so I can access it remotely (either the apache2 webserver or the FTP) using DDClient. Any packages installed have been installed using apt-get. Webmin, although discouraged in Ubuntu Server, is used mostly to administer the webserver aspect. This issue also appeared when I was using Ubuntu Server 10.10. After periods of heavy network traffic, whether local or remote, the connect drops. I'm talking specifically about the transfer of files via FTP, SCP or Samba (the latter of which I seldom use). There is no response to ping or ssh. I can't FTP to the server nor can I load the website. There are times when the server has been on for a few days and everything runs fine because I haven't accessed it much, if at all (thus not much network traffic). I've gone through a few hardware changes although I don't believe this has cause the issue: this has been happening long before I made any changes. At first I thought it was my ISP-provided router blocking traffic because of some kind of misconfiguration (perhaps assuming it was some kind of DoS attack). I've changed routers and still found no success. I've checked syslog, dmesg and kern.log for warnings but have uncovered none. I've ran memtest via the GRUB2 menu at boot and once it turned up 4 errors. I ran again with individual sticks of RAM in various slots and everything turned up fine. I've looked through the BIOS settings and everything looks fine. I've tried unplugging unnecessary pieces of hardware (other internal hard drives, CD drives, floppy, PCI cards, etc). Any help or tips on how I can even begin to troubleshoot this would be very much appreciated. Please note that i've only started playing with servers as a hobby so my knowledge wouldn't be the most refined. I'm comfortable with command line and have the initiative to know how to look up something I can't do. Unfortunately I can't seem to find any issues like this. Additionally: If a solution can't be found some assistance to write a script that will cause the server to reboot automatically if, after x minutes, it gets no response to pinging somewhere like google. Admittedly that's not the cleanest solution should my internet end up going down but I can't think of what else to do.

    Read the article

  • Block IP Address including ICMP using UFW

    - by dr jimbob
    I prefer ufw to iptables for configuring my software firewall. After reading about this vulnerability also on askubuntu, I decided to block the fixed IP of the control server: 212.7.208.65. I don't think I'm vulnerable to this particular worm (and understand the IP could easily change), but wanted to answer this particular comment about how you would configure a firewall to block it. I planned on using: # sudo ufw deny to 212.7.208.65 # sudo ufw deny from 212.7.208.65 However as a test that the rules were working, I tried pinging after I setup the rules and saw that my default ufw settings let ICMP through even from an IP address set to REJECT or DENY. # ping 212.7.208.65 PING 212.7.208.65 (212.7.208.65) 56(84) bytes of data. 64 bytes from 212.7.208.65: icmp_seq=1 ttl=52 time=79.6 ms ^C --- 212.7.208.65 ping statistics --- 1 packets transmitted, 1 received, 0% packet loss, time 0ms rtt min/avg/max/mdev = 79.630/79.630/79.630/0.000 ms Now, I'm worried that my ICMP settings are too generous (conceivably this or a future worm could setup an ICMP tunnel to bypass my firewall rules). I believe this is the relevant part of my iptables rules is given below (and even though grep doesn't show it; the rules are associated with the chains shown): # sudo iptables -L -n | grep -E '(INPUT|user-input|before-input|icmp |212.7.208.65)' Chain INPUT (policy DROP) ufw-before-input all -- 0.0.0.0/0 0.0.0.0/0 Chain ufw-before-input (1 references) ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0 icmp type 3 ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0 icmp type 4 ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0 icmp type 11 ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0 icmp type 12 ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0 icmp type 8 ufw-user-input all -- 0.0.0.0/0 0.0.0.0/0 Chain ufw-user-input (1 references) DROP all -- 0.0.0.0/0 212.7.208.65 DROP all -- 212.7.208.65 0.0.0.0/0 How should I go about making it so ufw blocks ICMP when I specifically attempt to block an IP address? My /etc/ufw/before.rules has in part: # ok icmp codes -A ufw-before-input -p icmp --icmp-type destination-unreachable -j ACCEPT -A ufw-before-input -p icmp --icmp-type source-quench -j ACCEPT -A ufw-before-input -p icmp --icmp-type time-exceeded -j ACCEPT -A ufw-before-input -p icmp --icmp-type parameter-problem -j ACCEPT -A ufw-before-input -p icmp --icmp-type echo-request -j ACCEPT I'm tried changing ACCEPT above to ufw-user-input: # ok icmp codes -A ufw-before-input -p icmp --icmp-type destination-unreachable -j ufw-user-input -A ufw-before-input -p icmp --icmp-type source-quench -j ufw-user-input -A ufw-before-input -p icmp --icmp-type time-exceeded -j ufw-user-input -A ufw-before-input -p icmp --icmp-type parameter-problem -j ufw-user-input -A ufw-before-input -p icmp --icmp-type echo-request -j ufw-user-input But ufw wouldn't restart after that. I'm not sure why (still troubleshooting) and also not sure if this is sensible? Will there be any negative effects (besides forcing the software firewall to force ICMP through a few more rules)?

    Read the article

  • Can't ping devices by IP address for devices allocated IPs by DHCP

    - by GiddyUpHorsey
    I have a home network with a Trendnet wireless router and a Windows Domain. The Domain Controller/DNS server is a Windows 2000 Server and is configured to forward queries to DNS servers provided by the ISP. The router provides DHCP and is configured with the Windows 2000 Server as the DNS server. The network has been set up for a couple of years and usually works fine. When I connect iPhones to the network over WiFi, the router can ping the iPhones through its browser based admin interface, but Windows machines that are part of the Windows Domain cannot. A laptop was connected to the network over WiFi that wasn't joined to the domain and it could see the iPhones. The router UI shows that the laptop has a reserved IP allocated via DHCP. All machines either have a static or DHCP allocated IP on the 192.168.0.* subnet. Router - 192.168.0.1 - Static - Wired Windows Domain Controller - 192.168.0.8 - Static - Virtual Windows 7 Workstation - 192.168.0.200 - DHCP Auto - Wired VMWare ESXi Host - 192.168.0.201 - Static? - Wired iPhone 1 - 192.168.0.202 - DHCP Auto - WiFi iPhone 2 - 192.168.0.203 - DHCP Auto - WiFi Windows Vista Laptop - 192.168.0.204 - DHCP Reserved - WiFi Using the Windows 7 machine (200), I try to ping each machine and the only DHCP machine that responds is itself. The other DHCP machines fail with Reply from 192.168.0.200: Destination host unreachable.. Using nslookup fails with *** domain.controller.name can't find 192.168.0.203: Non-existent domain. Using the Windows 2000 Domain Controller (8), I try to ping each machine and the only DHCP machine that responds is the Windows 7 machine (200). Pinging the other DHCP machines fails with Request timed out.. Using nslookup also fails with *** domain.controller.name can't find 192.168.0.203: Non-existent domain. Using the iPhone 2 (203), I try to ping (Network Ping Lite) the machines with static IP addresses and that works fine. When I try to ping the Windows 7 machine (200) it is unable to get a response. How do I configure the DNS server/Windows Domain/Router properly so that the Windows Domain machines can see the IPs allocated via DHCP?

    Read the article

  • HOSTS ignored when disconnected [closed]

    - by Synetech
    Problem I’m seeing a strange and extremely frustrating problem. Any system that is not connect to the Internet (Windows 7 shows the no Internet access icon because it cannot constantly ping Microsoft’s servers) cannot even access locally hosted servers. Hypothesis The problem appears to be that the HOSTS file is not being used to resolve DNS entries when there are no active NICs. Tests / Reproduction You can reproduce it as so: Disconnect a system from the Internet (make sure all wired and wireless connections are disconnected). If necessary, add an entry to the HOSTS file (e.g., 127.0.0.1 foobar or 127.0.0.1 foobar.com) Open a command-prompt Type ping foobar or ping foobar.com Observations The screenshots below show a clear and demonstrative example. In the first snap, a laptop is connected to a router wirelessly. The HOSTS file has only three entries and they resolve just fine. In the second snap, the wireless radio is turned off, so the entries in the HOSTS file are ignored. Moreover, notice that pinging localhost still works even without any active NICs (as does 127.0.0.1), but it is using the IPv6 address (must be hard-coded). You can see the same results in Windows XP with no IPv6 installed, so it has nothing to do with IPv6. I tried pining what should have resolved to 127.0.0.1 while the desktop system (with no wireless NICs) was connected via its Ethernet adapter, then again after pulling the cable from the router and waiting a couple of seconds, then again after plugging the cable back in. The same thing happens if instead of pulling out the cable, the NIC is disabled through software (the [Disable] button in the NIC’s Status dialog or via Device Manager). Conclusions It looks as though the HOSTS file is only being read and used if there is an active NIC, otherwise it is being ignored. This makes some sense in that if there are no active network adapters, then presumably there will not be any network activity, and thus no need to resolve host names via the HOSTS file. This assumption is specious however because it precludes locally hosted virtual servers. The HOSTS file should be used regardless of external DNS server connectivity, otherwise you cannot use simple/consistent/testing-production names for locally hosted servers when not connected to the Internet (for example web servers; help servers for Visual Studio, 3dsmax, etc.; and so on). Question Does anyone know how to force Windows to use the HOSTS file even if there are no active NICs? Appendix Figure 1: While the wireless NIC is connected to the router (the cable-modem is in standby, so no external Internet connectivity). Figure 2: With the wireless radio turned off (the Ethernet port is not unconnected in both cases). Figure 3: Same results in XP with no IPv6

    Read the article

  • Windows 2008 running as KVM guest networking issue

    - by Evolver
    I have a strange networking problem with Windows 2008 server R2, running as guest under KVM-Qemu host. Host is CentOS 6.3 x86_64. It's network settings: # cat /etc/sysconfig/network-scripts/ifcfg-br0 DEVICE=br0 BOOTPROTO=static BROADCAST=xx.xx.xx.63 IPADDR=xx.xx.xx.4 NETMASK=255.255.255.192 NETWORK=xx.xx.xx.0 ONBOOT=yes TYPE=Bridge # cat /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE=eth0 HWADDR=xx:xx:xx:xx:xx:xx ONBOOT=yes BRIDGE=br0 IPV6INIT=yes IPV6_AUTOCONF=yes # cat /etc/sysconfig/network NETWORKING=yes NETWORKING_IPV6=no HOSTNAME=my.hostname GATEWAY=xx.xx.xx.1 # cat /etc/sysctl net.ipv4.ip_forward = 1 # tried to set it to 0 without any changes net.ipv4.conf.default.rp_filter = 1 # tried to set it to 0 without any changes net.ipv4.conf.default.accept_source_route = 0 # tried to set it to 1 without any changes kernel.sysrq = 0 kernel.core_uses_pid = 1 net.ipv4.tcp_syncookies = 1 net.bridge.bridge-nf-call-ip6tables = 0 net.bridge.bridge-nf-call-iptables = 0 net.bridge.bridge-nf-call-arptables = 0 kernel.msgmnb = 65536 kernel.msgmax = 65536 kernel.shmmax = 68719476736 kernel.shmall = 4294967296 # route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface xx.xx.xx.0 0.0.0.0 255.255.255.192 U 0 0 0 br0 169.254.0.0 0.0.0.0 255.255.0.0 U 1004 0 0 br0 0.0.0.0 xx.xx.xx.1 0.0.0.0 UG 0 0 0 br0 Node IP is xx.xx.xx.4, guest IP is xx.xx.xx.24, both host and guest is in the same network (/26). There are several linux guest running fine on the node (centos, debian, ubuntu, arch), and even Windows 2003 x86 also running fine. But Win2008 does not. I wonder, what's the difference. From Win2008 guest I can ping nothing: neither gateway, nor any other IP, even they are in the same subnet. From outside I also cannot ping guest. Almost. If I ping it from another server in same subnet, it's barely pinging, losing more than 90% packets. Firewall on the guest is completely off. Tried to set up network manually as well as via DHCP without success (BTW, DHCP set up network settings correctly). I suspect that is a kind of routing problem, but I spent whole day and still cannot figure it out. I would be appreciate for any help.

    Read the article

  • Why can I view my site over a 3G connection but not through my wifi?

    - by Jonathan
    So, I am sitting in my office with four computers on the same network and internet connection. Two of the computers can visit this particular website. Two of the computer get a message "Google Chrome could not find". I have tried FF and IE also with the same problem. I can view the site 90% of the time on two of the working computers although the site seems slow and sometimes I also get the same errors as the other two computers. I have flushed the DNS, reset the router, tested the site on other peoples computers with success. Is this likely to be a site issue, an ISP issue, a hosting issue? Any advice is greatly appreciated. Here is the ping from the working machine: C:\Users\Jon>ping www.balihaicruises.com Pinging www.balihaicruises.com [208.113.173.102] with 32 bytes of data: Reply from 208.113.173.102: bytes=32 time=331ms TTL=47 Reply from 208.113.173.102: bytes=32 time=327ms TTL=47 Reply from 208.113.173.102: bytes=32 time=326ms TTL=47 Reply from 208.113.173.102: bytes=32 time=329ms TTL=47 Ping statistics for 208.113.173.102: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), Approximate round trip times in milli-seconds: Minimum = 326ms, Maximum = 331ms, Average = 328ms Traceroute: Tracing route to www.balihaicruises.com [208.113.173.102] over a maximum of 30 hops: 1 1 ms 17 ms 3 ms 192.168.1.1 2 42 ms 37 ms 36 ms 180.254.224.1 3 39 ms 47 ms 40 ms 180.252.1.69 4 36 ms 616 ms 57 ms 61.94.115.221 5 84 ms 76 ms 80 ms 180.240.191.98 6 73 ms 80 ms 72 ms 180.240.191.97 7 157 ms 143 ms 116 ms 180.240.190.82 8 115 ms 113 ms 120 ms ae1-123.hkg11.ip4.tinet.net [183.182.80.93] 9 331 ms 332 ms 335 ms xe-3-2-1.was14.ip4.tinet.net [89.149.184.30] 10 327 ms 330 ms 331 ms internap-gw.ip4.tinet.net [77.67.69.254] 11 437 ms 415 ms 350 ms border10.pc2-bbnet2.wdc002.pnap.net [216.52.127.73] 12 322 ms 823 ms 398 ms dreamhost-2.border10.wdc002.pnap.net [216.52.125.74] 13 328 ms 336 ms 326 ms ip-208-113-156-4.dreamhost.com [208.113.156.4] 14 326 ms 328 ms 336 ms ip-208-113-156-14.dreamhost.com [208.113.156.14] 15 327 ms 331 ms 333 ms apache2-udder.crisp.dreamhost.com [208.113.173.102] And then for the machine that doesn't work: C:\Users\Microsoft>ping www.balihaicruises.com Ping request could not find host www.balihaicruises.com. Please check the name and try again. C:\Users\Microsoft>tracert www.balihaicruises.com Unable to resolve target system name www.balihaicruises.com.

    Read the article

  • unable to join domain using virtualbox

    - by FreshPrinceOfSO
    I'm in the process of setting up a VM environment for a MS certification exam (70-462). Following the training kit's instructions, I've set up a domain controller (DC) and two members (SQL-A, SQL-B) thus far. I can't figure out why I can't join the domain. DC IPv4 Address . . . : 10.10.10.10(Preferred) Subnet Mask. . . . : 255.0.0.0 DNS Servers. . . . : ::1 127.0.0.1 SQL-A IPv4 Address . . . : 10.10.10.20(Preferred) Subnet Mask. . . . : 255.0.0.0 DNS Servers. . . . : 10.10.10.10 SQL-B IPv4 Address . . . : 10.10.10.30(Preferred) Subnet Mask. . . . : 255.0.0.0 DNS Servers. . . . : 10.10.10.10 I've read how to do networking between virtual machines in virtualbox and the documentation. After trying various network adapter configurations, I can't get them to communicate in order to have the two members join the domain. When I ping from .30 to .10, I get: ping 10.10.10.10 Pinging 10.10.10.10 with 32 bytes of data: Reply from 10.10.10.20: Destination host unreachable. Reply from 10.10.10.20: Destination host unreachable. Reply from 10.10.10.20: Destination host unreachable. Reply from 10.10.10.20: Destination host unreachable. Trying to join the domain: netdom join SQL-A /domain:contso.com The specified domain either does not exist or could not be contacted. The command failed to complete successfully. Within VirtualBox, I've tried the following combinations for network adapter: Attached to - Promiscuous Mode ------------------------------- NAT Bridged Adapter - Deny Bridged Adapter - Allow VMs Bridged Adapter - Allow All Internal Network - Deny Internal Network - Allow VMs Internal Network - Allow All Host-only Adapter - Deny Host-only Adapter - Allow VMs Host-only Adapter - Allow All Edit ipconfig /all of DC ipconfig /all of SQL-A

    Read the article

  • XP shared folders not accessible after BIOS changed

    - by stijn
    Here's what worked for over a year: PC A runs Windows 7, PC B runs Windows XP. Both are on the same subnet behind a router. A uses user account X, but logs in to PC B using the Administrator account. PC B is a Dell Precision 470. A known problem with these is that sometimes when plugging in their power cable they somehow loses all BIOS settings. This happened yesterday. After this happens Windows won't boot, because the default BIOS setting is 'RAID ON' while there is no RAID configured. No problem though, changing the BIOS settings to 'RAID OFF' makes it boot without problems. Note that in the meantime, nothing config-related was changed on machine A. It wasn't even on. Indeed after doing this, everything is fine. Everything includes all normal operations, remote desktop from PC A to PC B, running Synergy between A and B, accessing shared folders from B to A. But accessing the shared folders on B from A does not work any more. I tried pretty much everything I found via Google (fiddling with policies/registry kes/...) but no avail. > ping -a 192.168.2.2 Pinging A [192.168.2.2] with 32 bytes of data: Reply from 192.168.2.2: bytes=32 time<1ms TTL=128 > net view \\192.168.2.2 System error 5 has occurred. Access is denied. > net use /persistent:no K: \\A\myshare /user:A\USERNAME PASSWORD > net use /persistent:no K: \\192.168.2.2\myshare /user:192.168.2.2\USERNAME PASSWORD > net use /persistent:no K: \\192.168.2.2\myshare /user:USERNAME PASSWORD System error 86 has occurred. The specified network password is not correct. A solution to this would be great: I haven't been able to do any work since yesterday ;] update after taking the hard drive out of B and putting it in another Precision 470 with almost exactly the same hardware (at first sight, only the video card differs) the shared folders work.. Putting the disk back into A, same problem remains. Why does this depend on hardware, and more important, on which hardware?

    Read the article

  • unable to access a NAT'ed IP via a VPN on Windows 7

    - by crmpicco
    I connect to a range of servers hosted by one provider via a VPN. I can connect to the VPN fine, however when I then go and try and connect to the server(s) it fails. A NAT'ed IP address that has worked up until today, has stopped working either via SSH/SFTP. As you can see below, if I try and ping the IP then it responds with Destination host unreachable, but, for some reason it says the reply is from 192.168.0.8? If it enter this IP address in my browser, I get nothing. Where is this IP coming from and is there any good reason why I cannot access the IP I am trying to ping? C:\Users\crmpicco>ping 172.26.100.x Pinging 172.26.100.x with 32 bytes of data: Reply from 192.168.0.8: Destination host unreachable. Reply from 192.168.0.8: Destination host unreachable. Reply from 192.168.0.8: Destination host unreachable. Reply from 192.168.0.8: Destination host unreachable. Ping statistics for 172.26.100.x: Packets: Sent = 4, Received = 4, Lost = 0 (0% loss), I have the VPN remote host address of 80.75.67.x, which shows me as being connected. But i'm unsure if there is a config issue at the server side or my end that has caused this issue? I have had some recent Win7 (automatic) updates, but it's hard to tell if that's caused this problem. This is my output from arp: C:\Users\cmorton>arp -a Interface: 192.168.0.8 --- 0xe Internet Address Physical Address Type 192.168.0.1 00-18-4d-b9-68-5e dynami 192.168.0.6 00-f4-b9-68-0c-9a dynami 192.168.0.7 08-00-27-f2-9f-d6 dynami 192.168.0.255 ff-ff-ff-ff-ff-ff static 224.0.0.22 01-00-5e-00-00-16 static 224.0.0.251 01-00-5e-00-00-fb static 224.0.0.252 01-00-5e-00-00-fc static 239.255.255.250 01-00-5e-7f-ff-fa static 255.255.255.255 ff-ff-ff-ff-ff-ff static Interface: 192.168.56.1 --- 0x15 Internet Address Physical Address Type 192.168.56.255 ff-ff-ff-ff-ff-ff static 224.0.0.22 01-00-5e-00-00-16 static 224.0.0.251 01-00-5e-00-00-fb static 224.0.0.252 01-00-5e-00-00-fc static 255.255.255.255 ff-ff-ff-ff-ff-ff static

    Read the article

  • IPv6 routing to another interface

    - by Robert
    I'm trying to get an IPv6 enabled router to forward data from one interface to the other and I'm having issues. When following this example (http://www.cisco.com/en/US/tech/tk872/technologies_configuration_example09186a0080ba6106.shtml) I am able to get full connectivity between all 3 routers in my simulator. However when I try to use only 1 router; I can't get connectivity to the other interfacs on the same router. My PC is directly attached to FA 0/1 and it can ping the router's interface. However it can not ping any other interface on the router(which unless I'm missing something it should be able to do). The router on the other hand can ping everything. I thought static routes might help; but the router already has routes for everything. I'm thinking the packet should come in; router looks up the destination in it's ipv6 routing table and then realizes it's for itself, and should respond. I thought maybe it couldn't respond directly; so I tried pinging a device like 2001:0000:0000:1000::2, but i don't get a response. I'm running on IOS 12.4. I'm missing something(hopefully simple), but I just can't see what it is. With only 1 router; how do I enable my PC to talk to the other subnets? Thank you in advance, Robert Topology: R1 FA 0/0: 2001:0000:0000:0000::1/52 FA 0/1: 2001:0000:0000:1000::1/52 FA 1/0: 2001:0000:0000:2000::1/52 Loopback 0: 2001:0000:0000:3000::1/52 PC: 2001:0000:0000:2000::2/52 PC plugs directly into FA 1/0 on the router. --- Configuration --- ipv6 cef ipv6 unicast routing interface Loopback0 no ip address ipv6 address 2001:0000:0000:3000::1/52 ipv6 enable ! interface FastEthernet0/0 no ip address duplex auto speed auto ipv6 address 2001:0000:0000::1/52 ipv6 enable ! interface FastEthernet0/1 no ip address duplex auto speed auto ipv6 address 2001:0000:0000:1000::1/52 ipv6 enable ! interface FastEthernet1/0 no ip address duplex auto speed auto ipv6 address 2001:0000:0000:2000::1/52 ipv6 enable --- end of config --- --- routing table --- IPV6Lab#show ipv6 route IPv6 Routing Table - 10 entries Codes: C - Connected, L - Local, S - Static, R - RIP, B - BGP U - Per-user Static route I1 - ISIS L1, I2 - ISIS L2, IA - ISIS interarea, IS - ISIS summary O - OSPF intra, OI - OSPF inter, OE1 - OSPF ext 1, OE2 - OSPF ext 2 ON1 - OSPF NSSA ext 1, ON2 - OSPF NSSA ext 2 C 2001:0000:0000::/52 [0/0] via ::, FastEthernet0/0 L 2001:0000:0000::1/128 [0/0] via ::, FastEthernet0/0 C 2001:0000:0000:1000::/52 [0/0] via ::, FastEthernet0/1 L 2001:0000:0000:1000::1/128 [0/0] via ::, FastEthernet0/1 C 2001:0000:0000:2000::/52 [0/0] via ::, FastEthernet1/0 L 2001:0000:0000:2000::1/128 [0/0] via ::, FastEthernet1/0 C 2001:0000:0000:3000::/52 [0/0] via ::, Loopback0 L 2001:0000:0000:3000::1/128 [0/0] via ::, Loopback0 L FE80::/10 [0/0] via ::, Null0 L FF00::/8 [0/0] via ::, Null0 --- end of routing table ---

    Read the article

  • Gentoo box can't cURL or ping after restarting net.eth1

    - by Curlybraces
    Hi all, the following is completely baffling me. We currently have a gentoo box which acts as our LAMP, DNS, DHCP server. This is assigned a static IP on the network. This server is connected directly to the internet via a BT BusinessHub Router. The server is also connected to a patch panel/switch port which connects the remaining office (around 10 PC's) to the server. Everything has been plain sailing until the other day when the server was restarted. For some reason now only portions of network accessibility is available depending on which ethernet device was last restarted. Restarting net.eth0 allows the office server to cURL, ping, etc but stops all networked PC's from accessing the internet. Then restarting net.eth1 restores all internet to the network but stops the server from curling, pinging, etc again. However, even when the server can't ping, curl, etc, I can still remote SSH and remote MySQL connect from the server command line to other external servers that we own. Here's my route map (router is 192.168.1.254): Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth1 127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo 0.0.0.0 192.168.1.254 0.0.0.0 UG 0 0 0 eth1 Here's my /etc/conf.d/net: iface_eth0="192.168.1.99 broadcast 192.168.1.255 netmask 255.255.255.0" iface_eth1="dhcp" None of the above have ever been changed however. Things have just ceased to operate correctly, which makes me think it's a freshly added Iptables rule. Here's the Iptables Filter table: Chain INPUT (policy ACCEPT) target prot opt source destination DROP tcp -- ##.##.##.## anywhere tcp dpt:ssh ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED ACCEPT all -- anywhere anywhere ACCEPT tcp -- anywhere anywhere tcp dpt:2199 ACCEPT tcp -- anywhere anywhere tcp dpt:3199 ACCEPT tcp -- ##.###.###.## anywhere tcp dpt:http ACCEPT tcp -- ###.###.##.## anywhere tcp dpt:2199 ACCEPT tcp -- ##.###.###.### anywhere tcp dpt:http ACCEPT tcp -- ##.###.##.## anywhere tcp dpt:http ACCEPT tcp -- ##.###.###.### anywhere tcp dpt:3128 ACCEPT udp -- ##.###.###.### anywhere udp dpt:3128 ACCEPT tcp -- ##.###.###.### anywhere tcp dpt:http ACCEPT tcp -- ##.###.###.### anywhere tcp dpt:https Chain FORWARD (policy ACCEPT) target prot opt source destination ACCEPT all -- anywhere ##.###.###.## DROP all -- anywhere ##.###.###.## ACCEPT all -- anywhere anywhere state NEW,ESTABLISHED Chain OUTPUT (policy ACCEPT) target prot opt source destination ACCEPT udp -- anywhere anywhere udp spt:2199 ACCEPT udp -- anywhere anywhere udp spt:4817 ACCEPT udp -- anywhere anywhere udp spt:4819 ACCEPT udp -- anywhere anywhere udp spt:3199 Help gratefully appreciated.

    Read the article

  • Windows doesn't get access to internet though linux easily does

    - by flashnik
    We have a very interesting problem. The network is configured in this way: internet is connected to Trendnet switch TS DHCP server at 192.168.0.1 running on Ubuntu (S) is connected to internet switch DNS is also configured on 192.168.0.1 on S D-Link Wi-Fi boosters are connected to switch TS PCs use D-Link PCI-E Wi-Fi cards to get access to network PCs have both Ubuntu and Windows 7 There are about 40 PCs. When PC is booted to Ubuntu it easily gets access to internet. But when it's booted to Windows 7, it gets a valid IP-address, but doesn't get access to internet. The address, mask, DNS, GW-address are totally the same as when it's booted under Ubuntu. The S is reacheble and pingable. Sometimes when we are lucky the PC gets access to Internet, but after rebooting it can lose it. When PC under Windows has access, it has totally the same settings as when it doesn't. What can be done? UPDATE I shared a dropbox with 2 captures of traffic. Ping.pcap is a capture of pinging 8.8.8.8. And google-browser.pcap is a capture of opening a google.com in a browser, both of them are in tcpdump formats and made by Wireshark on Win PC. The MAC of Win PC ends on b7:63 and IP is 192.168.0.130. UPDATE2 This is ifconfig output from Ubuntu Server eth0 Link encap:Ethernet HWaddr 00:1e:67:13:d5:8d inet addr:193.200.211.74 Bcast:193.200.211.78 Mask:255.255.255.0 inet6 addr: fe80::21e:67ff:fe13:d58d/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:196284 errors:0 dropped:44 overruns:0 frame:0 TX packets:190682 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:158032255 (158.0 MB) TX bytes:156441225 (156.4 MB) Interrupt:19 Memory:c1400000-c1420000 eth0:2 Link encap:Ethernet HWaddr 00:1e:67:13:d5:8d inet addr:192.168.0.1 Bcast:192.168.0.254 Mask:255.255.255.0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 Interrupt:19 Memory:c1400000-c1420000 eth1 Link encap:Ethernet HWaddr 00:1e:67:13:d5:8c UP BROADCAST MULTICAST MTU:1500 Metric:1 RX packets:0 errors:0 dropped:0 overruns:0 frame:0 TX packets:0 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:0 (0.0 B) TX bytes:0 (0.0 B) Interrupt:16 Memory:c1300000-c1320000 nslookup from Win results in DNS request timeout, nbtstat in 'not found'.

    Read the article

  • Apache VirtualHost Blockhole (Eats All Requests on All Ports on an IP)

    - by Synetech inc.
    I’m exhausted. I just spent the last two hours chasing a goose that I have been after on-and-off for the past year. Here is the goal, put as succinctly as possible. Step 1: HOSTS File: 127.0.0.5 NastyAdServer.com 127.0.0.5 xssServer.com 127.0.0.5 SQLInjector.com 127.0.0.5 PornAds.com 127.0.0.5 OtherBadSites.com … Step 2: Apache httpd.conf <VirtualHost 127.0.0.5:80> ServerName adkiller DocumentRoot adkiller RewriteEngine On RewriteRule (\.(gif|jpg|png|jpeg)$) /p.png [L] RewriteRule (.*) /ad.htm [L] </VirtualHost> So basically what happens is that the HOSTS file redirects designated domains to the localhost, but to a specific loopback IP address. Apache listens for any requests on this address and serves either a transparent pixel graphic, or else an empty HTML file. Thus, any page or graphic on any of the bad sites is replaced with nothing (in other words an ad/malware/porn/etc. blocker). This works great as is (and has been for me for years now). The problem is that these bad things are no longer limited to just HTTP traffic. For example: <script src="http://NastyAdServer.com:99"> or <iframe src="https://PornAds.com/ad.html"> or a Trojan using ftp://spammaster.com/[email protected];[email protected];[email protected] or an app “phoning home” with private info in a crafted ICMP packet by pinging CardStealer.ru:99 Handling HTTPS is a relatively minor bump. I can create a separate VirtualHost just like the one above, replacing port 80 with 443, and adding in SSL directives. This leaves the other ports to be dealt with. I tried using * for the port, but then I get overlap errors. I tried redirecting all request to the HTTPS server and visa-versa but neither worked; either the SSL requests wouldn’t redirect correctly or else the HTTP requests gave the You’re speaking plain HTTP to an SSL-enabled server port… error. Further, I cannot figure out a way to test if other ports are being successfully redirected (I could try using a browser, but what about FTP, ICMP, etc.?) I realize that I could just use a port-blocker (eg ProtoWall, PeerBlock, etc.), but there’s two issues with that. First, I am blocking domains with this method, not IP addresses, so to use a port-blocker, I would have to get each and every domain’s IP, and update theme frequently. Second, using this method, I can have Apache keep logs of all the ad/malware/spam/etc. requests for future analysis (my current AdKiller logs are already 466MB right now). I appreciate any help in successfully setting up an Apache VirtualHost blackhole. Thanks.

    Read the article

  • Server 2012 intermittently fails to respond to pings from single host, even with firewall disabled, but responds to non-ICMP requests fine

    - by James Westbury
    This one is kind of weird. I've got the following machines involved: DC01 - 10.1.2.42, Server 2012, domain controller & DNS server, physical machine nagiosv - 10.1.2.35, CentOS 6.4, Nagios, virtual machine CB01 - 10.1.3.81, Ubuntu 12.04 LTS, couchbase server, virtual machine So, I noticed something was wrong while configuring this new Nagios VM. I started seeing DC01's state flapping. I logged into nagiosv when I saw this happening, and attempted to ping DC01, both by FQDN and its IP address. Neither worked. I tried pinging the machine from CB01, which is another VM on the same virtual switch/physical NIC as nagiosv, and that worked fine. Pings still failing from nagiosv at this time. DC01 is also an internal DNS server, so I ran dig google.com from nagiosv, and was able to run a query against DC01 just fine: ;; Query time: 1 msec ;; SERVER: 10.1.2.42#53(10.1.2.42) ;; WHEN: Fri Nov 1 07:53:51 2013 ;; MSG SIZE rcvd: 204 Pings still failing from nagiosv, though. I can ping from DC01 to nagiosv, and that works, and I can still ping from other VMs on the same physical NIC into DC01, and that works. I should mention at this point that I've disabled the firewall on DC01 for testing purposes, and it doesn't make a damned bit of difference. (Even with the firewall enabled, I have a blanket exception for ICMP from the local subnet, so it shouldn't make a difference, but I figured I should test it anyway.) I loaded up Wireshark on DC01 and pinged it from nagiosv again. What I see is a bunch of echo requests coming in and not a single reply going back out. Filtered results here, showing all ICMP traffic during a 15-second period. A few more bits of info: There are no IP conflicts on the network. MAC addresses on the incoming pings match the MAC on the VM. There are no duplicate MACs on the network, as far as I can see. I have absolutely no idea why DC01 is failing to respond, here. Any ideas?

    Read the article

  • Need help troubleshooting highly variable ping times

    - by Elliot.Bradshaw
    I'm at work using Citrix (think Remote Desktop) to connect to client sites. With my job I have to write a fair bit of code while I'm connected remotely via Citrix, so the latency of my internet connection is important. If I'm getting ping times above 250ms, then it becomes almost impossible to scroll, click or type with accuracy. Recently my Comcast business internet has been exhibiting highly variable ping times. If I ping google.com, I'll get pings that range from 9ms all the way up to 1300ms. The problem seems to be at its worst during the hours of 1PM to 4:30PM. Outside of those hours and the variance in pings settles down, mostly between 9ms and 50ms. The signal to noise ratio and upstream power are both fine on my modem--the values are here: http://pastebin.com/D4hWGPXf I ran a trace route from my computer to google.com (the results of which are here: http://pastebin.com/GcdjYvMh) and did another test ping to the IP of the first hop outside of our local network (73.98.44.1)--the variance in ping times existed in exactly the same manner as if I were pinging Google. Connecting directly to the cable modem by CAT5 makes no difference. Here is a screenshot demonstrating the variance of the ping times: http://postimage.org/image/haocdeauv/full/ -- as you can see it can get pretty bad. Three Comcast techs have been out (two of them were here when the problem wasn't happening) and they as well as the regional tier 2 Comcast support were unable to diagnose the problem. I now have a ticket open with tier 3 support, but have yet to hear back from them. Does anyone know what could cause these sorts of problems or have any idea from the traceroute above where it could be originating? The regional tier 2 guy tried to tell me that what I'm seeing is normal--are highly variable ping times like that ever acceptable? Anything I should ask Comcast to do or look at to get this problem fixed? Any tips/advice much appreciated! Edit: This is Comcast cable internet at a small start-up, we've ruled out congestion in our private LAN as a cause (i.e., no one's watching YouTube when the pings become variable). Update: Tier 3 Comcast support advised swapping out the modem, a tech came here today and did that--same problem persists.

    Read the article

  • [CentOS 4.8] nslookup resolves domains to IPs, but I can't get a response to pings to external servers

    - by Beco
    I have a fresh install of CentOS 4.8 running on an internal development server. I haven't done anything to it besides setting up sudoers and SSH. I can SSH into the server and from there resolve domains to IPs and ping internal servers, but for some reason I don't get any response from pinging external servers. The software firewall is disabled, and the problem is present with both static and DHCP-assigned network configurations. The network domain controller is a Windows Server 2003 box. $ nslookup google.com Server: 10.254.2.5 Address: 10.254.2.5#53 Non-authoritative answer: Name: google.com Address: 74.125.47.147 Name: google.com Address: 74.125.47.99 <etc...> 10.254.2.5 is the Win2K3 server. $ ping google.com PING google.com (74.125.47.106) 56(84) bytes of data. It just hangs here indefinitely. $ cat /etc/resolv.conf ; generated by /sbin/dhclient-script search <...snip...>.local nameserver 10.254.2.5 nameserver 10.254.2.124 10.254.2.124 is the backup DC server, which is currently off and tombstoned by this point. The snipped section is our company name. # ifconfig eth0 Link encap:Ethernet HWaddr <snip> inet addr:10.254.2.101 Bcast:10.254.2.255 Mask:255.255.255.0 inet6 addr: <snip>/64 Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:80066 errors:0 dropped:0 overruns:0 frame:0 TX packets:4421 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:1000 RX bytes:7810133 (7.4 MiB) TX bytes:590550 (576.7 KiB) Interrupt:225 Base address:0xc000 lo Link encap:Local Loopback inet addr:127.0.0.1 Mask:255.0.0.0 inet6 addr: ::1/128 Scope:Host UP LOOPBACK RUNNING MTU:16436 Metric:1 RX packets:32 errors:0 dropped:0 overruns:0 frame:0 TX packets:32 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:0 RX bytes:8104 (7.9 KiB) TX bytes:8104 (7.9 KiB) # route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 10.254.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0 0.0.0.0 10.254.2.5 0.0.0.0 UG 0 0 0 eth0 And, for good measure, a snapshot of the current ethernet config via the system-config-network GUI. Edit: I don't yet have enough rep to post images, so here's a link. Sorry! system-config-network snapshot I'm pretty green when it comes to setting up *nix dev servers and network configuration in general, so please let me know if I've left out critical information, or posted information I shouldn't have posted. Thanks!

    Read the article

  • Computer Networks UNISA - Chap 15 &ndash; Network Management

    - by MarkPearl
    After reading this section you should be able to Understand network management and the importance of documentation, baseline measurements, policies, and regulations to assess and maintain a network’s health. Manage a network’s performance using SNMP-based network management software, system and event logs, and traffic-shaping techniques Identify the reasons for and elements of an asset managements system Plan and follow regular hardware and software maintenance routines Fundamentals of Network Management Network management refers to the assessment, monitoring, and maintenance of all aspects of a network including checking for hardware faults, ensuring high QoS, maintaining records of network assets, etc. Scope of network management differs depending on the size and requirements of the network. All sub topics of network management share the goals of enhancing the efficiency and performance while preventing costly downtime or loss. Documentation The way documentation is stored may vary, but to adequately manage a network one should at least record the following… Physical topology (types of LAN and WAN topologies – ring, star, hybrid) Access method (does it use Ethernet 802.3, token ring, etc.) Protocols Devices (Switches, routers, etc) Operating Systems Applications Configurations (What version of operating system and config files for serve / client software) Baseline Measurements A baseline is a report of the network’s current state of operation. Baseline measurements might include the utilization rate for your network backbone, number of users logged on per day, etc. Baseline measurements allow you to compare future performance increases or decreases caused by network changes or events with past network performance. Obtaining baseline measurements is the only way to know for certain whether a pattern of usage has changed, or whether a network upgrade has made a difference. There are various tools available for measuring baseline performance on a network. Policies, Procedures, and Regulations Following rules helps limit chaos, confusion, and possibly downtime. The following policies and procedures and regulations make for sound network management. Media installations and management (includes designing physical layout of cable, etc.) Network addressing policies (includes choosing and applying a an addressing scheme) Resource sharing and naming conventions (includes rules for logon ID’s) Security related policies Troubleshooting procedures Backup and disaster recovery procedures In addition to internal policies, a network manager must consider external regulatory rules. Fault and Performance Management After documenting every aspect of your network and following policies and best practices, you are ready to asses you networks status on an on going basis. This process includes both performance management and fault management. Network Management Software To accomplish both fault and performance management, organizations often use enterprise-wide network management software. There various software packages that do this, each collect data from multiple networked devices at regular intervals, in a process called polling. Each managed device runs a network management agent. So as not to affect the performance of a device while collecting information, agents do not demand significant processing resources. The definition of a managed devices and their data are collected in a MIB (Management Information Base). Agents communicate information about managed devices via any of several application layer protocols. On modern networks most agents use SNMP which is part of the TCP/IP suite and typically runs over UDP on port 161. Because of the flexibility and sophisticated network management applications are a challenge to configure and fine-tune. One needs to be careful to only collect relevant information and not cause performance issues (i.e. pinging a device every 5 seconds can be a problem with thousands of devices). MRTG (Multi Router Traffic Grapher) is a simple command line utility that uses SNMP to poll devices and collects data in a log file. MRTG can be used with Windows, UNIX and Linux. System and Event Logs Virtually every condition recognized by an operating system can be recorded. This is typically done using event logs. In Windows there is a GUI event log viewer. Similar information is recorded in UNIX and Linux in a system log. Much of the information collected in event logs and syslog files does not point to a problem, even if it is marked with a warning so it is important to filter your logs appropriately to reduce the noise. Traffic Shaping When a network must handle high volumes of network traffic, users benefit from performance management technique called traffic shaping. Traffic shaping involves manipulating certain characteristics of packets, data streams, or connections to manage the type and amount of traffic traversing a network or interface at any moment. Its goals are to assure timely delivery of the most important traffic while offering the best possible performance for all users. Several types of traffic prioritization exist including prioritizing traffic according to any of the following characteristics… Protocol IP address User group DiffServr VLAN tag in a Data Link layer frame Service or application Caching In addition to traffic shaping, a network or host might use caching to improve performance. Caching is the local storage of frequently needed files that would otherwise be obtained from an external source. By keeping files close to the requester, caching allows the user to access those files quickly. The most common type of caching is Web caching, in which Web pages are stored locally. To an ISP, caching is much more than just convenience. It prevents a significant volume of WAN traffic, thus improving performance and saving money. Asset Management Another key component in managing networks is identifying and tracking its hardware. This is called asset management. The first step to asset management is to take an inventory of each node on the network. You will also want to keep records of every piece of software purchased by your organization. Asset management simplifies maintaining and upgrading the network chiefly because you know what the system includes. In addition, asset management provides network administrators with information about the costs and benefits of certain types of hardware or software. Change Management Networks are always in a stage of flux with various aspects including… Software changes and patches Client Upgrades Shared Application Upgrades NOS Upgrades Hardware and Physical Plant Changes Cabling Upgrades Backbone Upgrades For a detailed explanation on each of these read the textbook (Page 750 – 761)

    Read the article

< Previous Page | 8 9 10 11 12 13 14  | Next Page >