Search Results

Search found 8555 results on 343 pages for 'virtualbox networking'.

Page 185/343 | < Previous Page | 181 182 183 184 185 186 187 188 189 190 191 192  | Next Page >

  • Switch flooding when bonding interfaces in Linux

    - by John Philips
    +--------+ | Host A | +----+---+ | eth0 (AA:AA:AA:AA:AA:AA) | | +----+-----+ | Switch 1 | (layer2/3) +----+-----+ | +----+-----+ | Switch 2 | +----+-----+ | +----------+----------+ +-------------------------+ Switch 3 +-------------------------+ | +----+-----------+----+ | | | | | | | | | | eth0 (B0:B0:B0:B0:B0:B0) | | eth4 (B4:B4:B4:B4:B4:B4) | | +----+-----------+----+ | | | Host B | | | +----+-----------+----+ | | eth1 (B1:B1:B1:B1:B1:B1) | | eth5 (B5:B5:B5:B5:B5:B5) | | | | | | | | | +------------------------------+ +------------------------------+ Topology overview Host A has a single NIC. Host B has four NICs which are bonded using the balance-alb mode. Both hosts run RHEL 6.0, and both are on the same IPv4 subnet. Traffic analysis Host A is sending data to Host B using some SQL database application. Traffic from Host A to Host B: The source int/MAC is eth0/AA:AA:AA:AA:AA:AA, the destination int/MAC is eth5/B5:B5:B5:B5:B5:B5. Traffic from Host B to Host A: The source int/MAC is eth0/B0:B0:B0:B0:B0:B0, the destination int/MAC is eth0/AA:AA:AA:AA:AA:AA. Once the TCP connection has been established, Host B sends no further frames out eth5. The MAC address of eth5 expires from the bridge tables of both Switch 1 & Switch 2. Switch 1 continues to receive frames from Host A which are destined for B5:B5:B5:B5:B5:B5. Because Switch 1 and Switch 2 no longer have bridge table entries for B5:B5:B5:B5:B5:B5, they flood the frames out all ports on the same VLAN (except for the one it came in on, of course). Reproduce If you ping Host B from a workstation which is connected to either Switch 1 or 2, B5:B5:B5:B5:B5:B5 re-enters the bridge tables and the flooding stops. After five minutes (the default bridge table timeout), flooding resumes. Question It is clear that on Host B, frames arrive on eth5 and exit out eth0. This seems ok as that's what the Linux bonding algorithm is designed to do - balance incoming and outgoing traffic. But since the switch stops receiving frames with the source MAC of eth5, it gets timed out of the bridge table, resulting in flooding. Is this normal? Why aren't any more frames originating from eth5? Is it because there is simply no other traffic going on (the only connection is a single large data transfer from Host A)? I've researched this for a long time and haven't found an answer. Documentation states that no switch changes are necessary when using mode 6 of the Linux interface bonding (balance-alb). Is this behavior occurring because Host B doesn't send any further packets out of eth5, whereas in normal circumstances it's expected that it would? One solution is to setup a cron job which pings Host B to keep the bridge table entries from timing out, but that seems like a dirty hack.

    Read the article

  • Doing port forwarding and then using it from within the internal network

    - by Ram Rachum
    We all know that by doing port forwarding on the router, computers from outside the network are able, on the specified ports, to access internal computers by targeting the external IP. I'm now replacing a TP-Link router with a D-link VDSL N 6740U router, (and copied over all the settings,) and I've noticed that one thing stopped working: With the TP-link router, you could access those port-forwarded computers from within the network, using the external IP, and they would be forwarded to the relevant computers. With the new D-Link router, it doesn't work. You might be wondering, why would you want to use the external IP and port forwarding when you're inside the internal network anyway and can just access the internal IP? One example for why this is useful: You have an iPhone app that connects to a service on an internal computer. The iPhone app knows to connect to the external IP. When we put that iPhone inside the internal network (via WiFi), it suddenly stops working, because it can't access the service from the external IP anymore. Is it an inherent property of D-Link routers that they do not allow accessing internal servers from inside the network by targeting the external IP? Or is there a way to make it work?

    Read the article

  • Authentication required by wireless network

    - by Roman
    I would like to use a wireless network from Ubuntu. In the network drop-down menu I select a network (this is a University network I have an account there). Then I get a windows with the following fields: Wireless Security: [WPA&WPA2 Enterprise] Authentication: [Tunneled TLS] Anonymous Identity: [] CA Certificate: [(None)] Inner Authentication: [some letters] User Name: [] Password: [] I put there my user name and password and do not change default value and leave "Anonymous Identity"blank. As a result of that I get "Authentication required by wireless network". How can I solve this problem? I think it is important to notice that our system administrator tried to find some files (which are probably needed to be used as "CA Certificate"). He said that he does not know where this file is located on Ubuntu (he support only Windows). So, probably this is direction I need to go. I need to find this file. But may be I am wrong. May be something else needs to be done. Could you pleas help me with that?

    Read the article

  • Small office network setups

    - by user39822
    I work at a small office and we're overhauling our network setup there. We're a web dev company and at the moment we have 50+ production sites running on the same machine that runs our internal email, which is just plain stupid. We're moving all our client hosting off site and are now looking for something to run our internal office requirement. Below is a brain dump: Equal amount of Mac & PC, about 25 machines in total. We need a central "server" to host files that should be accessible everyone as a "network drive". If possible we'd like to use low cost hardware for this (Mac or Win based). Disk space should be upward of 1TB. Ideally we should also be able to run a small web server on this machine (LAMP stack) to run some planning and billing applications we wrote ourselves. We need some sort of MS Exchange alternative for things like a shared calendar and especially being able to set Out of Office replies. We have one printer that is connected to the network Setup should be something can preferably be managed easily via a graphical interface and NOT require command line skills. Users want to keep using Apple Mail or MS Outlook After a quick google I came across the Zimbra collaboration suite, can anyone recommend this or any other solution for our office?

    Read the article

  • Shielded ethernet cable and ethernet sockets earthing how to?

    - by ageis23
    Hi I'm going to install 5 Ethernet sockets in my house using cat5e shielded cable. I decided to use this because the sockets will be on the second floor and the most practical way up is within a trunk along with some mains wiring. The cable will be terminated at the router and at the Ethernet faceplate. What can I use to earth then? The faceplate/router are both plastic hence no earth wire needed. I can't use the earth wire within the main socket can I? I figured it will be very very dangerous. I don't want to be connecting to the earth block on the mains either since I totally incompetent when it comes to mains electricity.

    Read the article

  • Alfa AWUSO36H 1W dysfunctional driver

    - by BrainStorm
    I recently purchased an Alfa AWUSO36H 1W wireless USB adapter for my notebook, in order to improve signal strength and quality. I'm currently using Linux Mint 11, and the it uses the RTL8187 driver for this adapter, I'm also using a 4dbi antenna, though I have others. The problem is that this adapter does exactly the opposite of what it should, actually my internal Broadcom BCM4313 adapter works way better than the alfa. Browsing is slow, some network applications don't even work, pings against Google.com on the internal adapter runs smooth, while in the alfa it gets like 25% packets lost or more! I'm less them 50 feet from my AP, the internal adapter gets 44/70 link quality, and the alfa gets around 60/70 (iwconfig output). Also the system always sets alfa power to 20dbm(100mw), then I have to do sudo iw set reg B0 to make it 30dbm(1000mw), but apparently no significant change. I've installed wireless-compat drivers, no change either. And worst of all, in Windows 7 it works way more smoothly for browsing, though I couldn't test it properly there. I hope its a driver problem, even if it's a pain to find/compile Linux drivers for a starter, I prefer it to a hardware problem where I would need to buy another adapter, since I have no money left (except for the cantenna pieces).

    Read the article

  • Is there any way to set up a malware-blocking transparent proxy on an Airport Extreme?

    - by Chris R
    I'd like to add some kind of easily-administered transparent HTTP proxy to my home network. Ideally, it would allow me to, for example, redirect web requests to blacklisted servers into nothing, block certain kinds of content, et al. My home network at the moment consists of a mac mini media server that could -- if the load wasn't huge -- fill this role as well, an Airport Extreme, and a mac laptop that is my main machine. I'm reasonably technically savvy, so don't spare the complicated answers.

    Read the article

  • OpenVPN multiple servers on the same subnet, high availability

    - by andre
    Hey everyone. Let me start by saying that my Linux experience isn't super awesome but I can usually find my way around things easily. Over at work we have an OpenVPN setup that's been due for some improvement for a while now. The main server (tap mode) runs in our office, behind a rather slow DSL connection. The main problem is that, since I'm usually out of the office, every time I want to access something on the virtual network I have to go through that server to get anywhere else. We have two servers up on 100 Mbit connections that we use for development and production purposes, about 3 more servers in the office (one of them behind a different T1 line for VOIP) and about two dozen clients who use the network on a daily basis from various locations. We've had situations where network routing (outside of our control) would not allow people to reach our main OpenVPN server whilst the other locations were connectable. Also any time someone outside the office wants to fetch something from any of the servers (say, a 500 MB code repository), a whopping 20 KB/s download speed is just unacceptable these days (did I mention slow DSL? ok). We had to implement traffic shaping on this server since maxing out this connection was fairly trivial. I had the thought of running two (or more) OpenVPN servers in the network. These would have to have the same subnet though, as our application relies on virtual network's IP addresses for some of its core functionality. The clients would also preferably retain the same IP addresses but that's not vital. For simplicity, lets call the current server office and the second server I'm setting up, cloud. Call the server on the T1 phone. This proved to be rather complex because as soon as I connect to cloud, I cannot see office. Any routes to a server that would go through office also do not work while I'm connected to cloud (no ping, nothing) and vice-versa. There's no rules for iptables that would be blocking the traffic either. Recently I came across this article on linuxjournal but the solution they provide seems to only cover the use of two servers and somewhat outdated (can't even find much documentation, their wiki is offline). They also state that adding more servers would be a complex task. Ideally I would like to keep the existing server office running the virtual network and also run the OpenVPN daemon on the cloud and phone servers (100 Mbit and very reliable connection, respectively) so that we're on safe ground in case of a hardware failure, DSL failure, etc. So, in essence, I'm looking for a highly available OpenVPN solution (fix, patch, hack, tweak, whatever you want to call it) that will accept connections on multiple hosts (2 or more) whilst keeping the same IP address subnet regardless of the server to which you connect to. Thanks for reading and sorry for the long post, I hope it gets the point across :P

    Read the article

  • Retrieve a domain name based on an IP Address?

    - by Neil Kodner
    I'm reviewing some apache logs, specifically with respect to downloaded files. I'm interested in knowing, if possible, which domain is responsible for the download, given an IP address. I've given nslookup a try and it seems to (mostly) get the job done but it returns all sorts of extraneous information. Ideally, I pass in an IP and receive a domain back. Before I write a shell script to parse the output of nslookup to capture the domain, I'd like to know if this is the best way of approaching this problem, or if there is a more tried-and-true method of doing this. Specifically, I'd like to know if an address resolves to an amazonaws.com domain. I understand that this might be difficult because EC2 machines are dynamically created and destroyed - I'd like to know if the IP addresses for AWS/EC2/EMR machines fit any sort of addressing pattern.

    Read the article

  • Funnelling http traffic

    - by spencer p
    I have a situation where a large batch of servers (X), on demand, need to request data from a smaller set of web servers (Y). The worst case scenario is if all servers in X decide to fetch different requests to one server in Y. That would be X amount of connections, which could be a very large burst of traffic. The best case scenario is if 1 server in X hit 1 server in Y in tandem. Life does not work like this. One idea to entertain is placing a proxy, similar to squid between X and Y. All of X servers can connect to this proxy, but would result in a few persistent (http keepalive) connections to Y. If The few were say, 3 or 4, then it would funnel. If we could then rate limit those connections and traffic decides to spike unusually high, we wouldn't hurt anyone but ourselves. Thoughts?

    Read the article

  • convert home phone wiring to Ethernet

    - by aaa
    can i convert phone wiring in walls to act as only Ethernet network cause the phone wiring is not in use and not connected to the phone company so there is no voltage in the wires i remove the wall plate and i find 6 wires blue,blue/white,green,green/white,orange,orange/white , and i know that Ethernet use 8 here is what i am thinking get Ethernet cable cut it in half and attach wires from wall to the first computer and the same with the other computer so if this is possible do i just attach wires in the same color and ignore brown wire or do i have to rearrange wires , and how much the speed will be thank you in advance

    Read the article

  • Best way to troubleshoot intermittent network outages?

    - by Ben Scheirman
    We have a Comcast 50/10 line into our office. We keep seeing very short but sometimes frequent drops in our internet service. It's enough to kick you off of skype and stop any websites from loading, which is obviously affecting our productivity. We've tried 4 different routers, we've tried moving everyone off of wireless and onto wired via a switch and so far nothing has helped. Right now we're on a Cisco SB WRP400-G1 router. Attached to the router is a 16 port switch going to the ports in all of the offices. We've moved to OpenDNS in the case that it was the comcast DNS servers going down. Today we tried putting the modem, router, and switch on a UPS to make sure it wasn't power fluctuations that was causing it. Every time we call Comcast, by the time they are here the internet is working fine. I'd like to somehow prove that the problem is with Comcast, so if that means plugging in a machine directly into their router and collecting data all day, I'm up for that. I just want to hear ideas on what tools to run and how to collect this data. I could just continuously ping google.com all day long but I'm not sure how valuable that data would be. Thoughts?

    Read the article

  • I don't get any Internet when I connect connect Cisco DPC3825 DOCSIS 3.0 Gateway with DLink DIR-625 [on hold]

    - by Asif Akhtar
    I am using Cisco DPC3825 DOCSIS 3.0 Gateway as my modem and router right now and it works fine on a computer directly connected to Cisco DPC3825 DOCSIS 3.0 Gateway with wire but I am getting very low/poor signal strength on my wireless computer due to which I am looking to install DLink DIR-625 as my router but because when I connect Cisco DPC3825 DOCSIS 3.0 Gateway with DLink DIR-625 and connect my computer with wire to DIR-625 then I don’t get any Internet.(I get Internet when I connect my computer with wire with Cisco DPC3825 DOCSIS 3.0 and I know there is nothing wrong with DLink DIR-625).

    Read the article

  • Not getting IP from ISP on Multicast Network

    - by Johan Nielsen
    Im having an odd issue with my ISP (COMX.dk) I have a managed access gateway box (Telsay) with three 8P8C ports for use with Internet and Ip-Tv (respectively on different VLANS (so does my ISP tell me)) To utilize a port you will need to register your device's mac address through an online interface. You will then get your device paired with a static ip. I am using one port actively and I have registered another device (router). The router is configured to listen for an active dhcpd on the network. When my router get a lease I get a private ip 192.168.2.2 (not the one bound to my mac) which is odd! I unconnected my router from the gateway and connected my laptop directly. Same thing happened - I was given a private address. I did a port scan on the gateway and found port 80 to be open and browsed to the ip. I was then presented with a management interface of a Belkin wireless router (HMMM!!!!) <--by the way, not my gear At this point I called the ISP to let them know of my issue/findings - Only to be replied "Well, we cant see any rogue dhcp servers" (thinking to myself, well I can) I then decided that it could be fun to try the other port of my gateway, only to experience the same. So I reconnected my router and used the remaining port to make an observer(wireshark promic etc.) I am able to see my router trying to discover a dhcp server but I can also see my ISP's IGMP and PIMv2 packages just repeating the same pattern. Hello...Hello...Hello :) So I called them again, only to get the same response, "we dont see any rogue dhcp's...we cant see the host you are talking to (mac address of the Belkin router)...you are definitively connected through wireless?!?(no im not, no such thing as a wireless wire - i thought to myself)" My questions is, What is going on? (besides from what im reporting here) What am I seeing that the don't? What can I tell them in order for them to resolve mine/their issue?

    Read the article

  • Slow Local Network, Windows 7, Snow Leopard, WiFi/Wired

    - by WerkkreW
    I am experiencing really poor local network performance in my home. I was recently using a Linksys WRT54G Router with DD-WRT on it, and a couple comparable Linksys-G PCI cards for connectivity but decided to upgrade hoping it would help with my performance issues. The computers in my house are connected as follows: Comcast Business Class Commercial 25mbps/10mbps (Verified) D-Link DGL-4500 Wireless N Router Windows 7x64 - D-Link DWA-552 Wireless-N Windows 7x64 - D-Link DWA-552 Wireless-N Mac Mini 10.6.2 - AirPort Extreme N Playstation 3, Hard Wired Xbox 360, Hard Wired Essentially the problem is very specific. Web browsing and uploading/downloading files from the internet is fine, more than fine. But if I want to say, Stream a video from one of my Windows 7 computers to my PS3, or copy a large video file between either of the PC's or the Mac, I get a consistent 500-900Kbps throughput at the high end. If I open my network browser, or try to browse my homegroup the response time is horrible. Both of my Windows computers are showing Strong wireless signals with a connection speed of 300Mbps. I know I can never expect to achieve anything near those speeds, but 500Kbps? Here is what I have tried so far: Enabled Single mode N-only and N/G Only on router WPA2 with AES Encrpytion Disabled "Remote Differential Compression" in Windows 7 Disabled TCP "Auto-Tuning" Used other software for file copies such as "Teracopy" I am at the end of my rope. Unfortunately I live in a 75 year old home with plaster walls, so hard-wiring my entire house isn't really an option I can handle right now. Any ideas to help me get decent speed when transferring files across my network would be greatly appreciated.

    Read the article

  • Routing application traffic through specific interface

    - by UnicornsAndRainbows
    Hello All! First question here, so please go easy: I have a debian linux 5.0 server with two public interfaces. I would like to route outbound traffic from one instance of an application via one interface and the second instance through the second interface. There are some challenges: both instances of the application use the same protocol both instances of the application can access the entire internet (can't route based on dest network) I can't change the code of the application I don't think a typical approach to load balancing all traffic is going to work well, because there are relatively few destination servers being accessed in the outbound traffic, and all traffic would really need to be distributed pretty evenly across these relatively few servers. I could probably run two virtualized servers on the box and bind each of them to a different external ip, but I'm looking for a simpler solution, maybe using iproute or iptables? Any ideas for me? Thanks in advance - and I'm happy to answer any questions.

    Read the article

  • Users and Groups management on 7 Home Premium

    - by AviD
    Recently upgraded the home pc from XP pro, to Windows 7 Home Premium. I'm looking for a solution for a few things that seem to be missing from this edition... Since Local Users and Groups is blocked on Home Premium, I can't figure out how to manage groups, or even do anything even slightly advanced to users (basically, create/group/picture is it). net localgroup, net users, net etc dont seem to work - getting "system error 5". While I'm on the topic, I cant activate (what was once) "Local Security Policy"... Looking for any help, advice, or even a new direction cuz things is differ'nt on Winnows7... To clarify, I'm looking to do some of the following, which were simply back in XP-land: remote user only (i.e. no local logon) Grant special privileges for specific user grant access to e.g. C$ share for specific remote user create custom groups for users, to be able to separate privileges of say, my wife's from my kids define quite specifically what each user can do (beyond just standard users) Harden OS (hmm, i guess maybe what i'm looking for is security hardening guide for 7...?)

    Read the article

  • Why PowerConnect and Juniper are so rare ? Why do enterprises stick with Cisco ?

    - by Kedare
    Hello ! I have a little question, I'm actually studing in IT in France, and when looking on alternative on the very [...] very expensive Cisco equipment, I've found Juniper and DELL PowerConnect pretty attractive on features and price, but I rarely see something else than the classics Cisco/LinkSys, HP Procurve and Netgear.. Why it's so rare to find those switch ? They looks really great but... I've never seen any Juniper or Powerconnect... Why do enterprises stick with the expensive Cisco ? I've tried to find how to buy both, it's quite easy with PowerConnect, everything is on the DELL website, but it looks it's very hard to find Juniper equipment in France :( Thank you !

    Read the article

  • Windows VPN not authenticating from ADSL to Wireless link

    - by deanvz
    I have a normal windows VPN on a computer connecting to a 196.201.x.x/24 IP. If this VPN tries to connect from any address in the 41.x.x.x range it cant get there. The server is a normal windows 2008 server, running exchange with a PPPoE IP natted to a public IP on the public gateway of the wireless network as the server is on site and its connectivity is derived from Mikrotik RB's. The computer on the 41 range can traceroute and ping the server, but the VPN does not authenticate. When on the network or any other, the VPN works fine. Is there something that could be configured on the VPN client? All firewall settings of a standard ADSL router have been checked and found to block only ICMP's. Is this a VPN configuration problem or a network issue?

    Read the article

  • TCPDump and IPTables DROP by string

    - by Tiffany Walker
    by using tcpdump -nlASX -s 0 -vvv port 80 I get something like: 14:58:55.121160 IP (tos 0x0, ttl 64, id 49764, offset 0, flags [DF], proto TCP (6), length 1480) 206.72.206.58.http > 2.187.196.7.4624: Flags [.], cksum 0x6900 (incorrect -> 0xcd18), seq 1672149449:1672150889, ack 4202197968, win 15340, length 1440 0x0000: 4500 05c8 c264 4000 4006 0f86 ce48 ce3a E....d@[email protected].: 0x0010: 02bb c407 0050 1210 63aa f9c9 fa78 73d0 .....P..c....xs. 0x0020: 5010 3bec 6900 0000 0f29 95cc fac4 2854 P.;.i....)....(T 0x0030: c0e7 3384 e89a 74fa 8d8c a069 f93f fc40 ..3...t....i.?.@ 0x0040: 1561 af61 1cf3 0d9c 3460 aa23 0b54 aac0 .a.a....4`.#.T.. 0x0050: 5090 ced1 b7bf 8857 c476 e1c0 8814 81ed P......W.v...... 0x0060: 9e85 87e8 d693 b637 bd3a 56ef c5fa 77e8 .......7.:V...w. 0x0070: 3035 743a 283e 89c7 ced8 c7c1 cff9 6ca3 05t:(>........l. 0x0080: 5f3f 0162 ebf1 419e c410 7180 7cd0 29e1 _?.b..A...q.|.). 0x0090: fec9 c708 0f01 9b2f a96b 20fe b95a 31cf ......./.k...Z1. 0x00a0: 8166 3612 bac9 4e8d 7087 4974 0063 1270 .f6...N.p.It.c.p What do I pull to use IPTables to block via string. Or is there a better way to block attacks that have something in common? Question is: Can I pick any piece from that IP packet and call it a string? iptables -A INPUT -m string --alog bm --string attack_string -j DROP In other words: In some cases I can ban with TTL=xxx and use that should an attack have the same TTL. Sure it will block some legit packets but if it means keeping the box up it works till the attack goes away but I would like to LEARN how to FIND other common things in a packet to block with IPTables

    Read the article

  • Host ::1 resolves to remote IP

    - by thebuckst0p
    /etc/hosts files usually have this line, ::1 localhost. I thought ::1 was the equivalent of 127.0.0.1/localhost, and from my reading it seems to be the IPv6 version. So I was using it in Apache for firewalling, "Allow from ::1" and it only allowed local. Then suddenly that stopped working, so I pinged ::1 and got a remote IP address. I tracerouted it and it went through my ISP, through some Microsoft server, then another half dozen steps of asterisks... I'm not sure why this would be (the remote IP), but it doesn't seem good. I grep'd my hard drive for the remote IP and it doesn't appear anywhere. Is this some indicator that I'm being hacked, or normal behavior? Maybe my IPv6 settings are wrong? (This is a brand new MacBookPro with Snow Leopard.) Any ideas about this would be great - what is ::1 supposed to be, why would it be remote, should I be worried, how do I get it back to localhost? Thank you!

    Read the article

  • How to masked network directory with Active Directory & IIS7

    - by Zach Shallbetter
    Departments within our organization have file directories on our IIS7 2008 R2 server similar to \\apollo\marketing.oems, which are outward facing for clients. We would like to create masked directories for quicker access like \\marketing that would point to \\apollo\marketing.oems. I've done research and have not come across any real answers, although I know it's possible Any help would be appreciated.

    Read the article

< Previous Page | 181 182 183 184 185 186 187 188 189 190 191 192  | Next Page >