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Single m0n0wall - Two LAN Subnets - How To Setup

- by SnAzBaZ

I have two LAN subnets that I need to link together they are 192.168.4.0/24 and 192.168.5.0/24 There is a m0n0wall running on 192.168.4.1. It's LAN connection goes out to our network switch, and it's WAN port goes out to our ADSL modem. WAN is connected via PPPoE. The 192.168.4.0 subnet contains all of our office workstations. The 192.168.5.0 subnet contains development servers and test machines that need to obtain internet access and be "managed" by computers on the 192.168.4.0 subnet, but need to be on their own subnet as well. I have a Draytek 2820N configured on 192.168.5.1 with it's WAN2 port configured as 192.168.4.25 and a default gateway of 192.168.4.1. Machines on the 5.0 subnet can connect to the internet via the m0n0wall just fine. I configured a static route on the m0n0wall LAN interface, Network 192.168.5.0/24 and Gateway 192.168.4.25. Machines on the 5.0 subnet can ping machines on the 4.0 network but the reverse does not work. I configured a new firewall rule on the m0n0wall that allows any traffic on the LAN interface with a source IP of 192.168.4.25 to be allowed. The DrayTek firewall is currently configured to pass all traffic regardless. When I try to ping a machine in the 5.0 subnet from 4.0 I see this in my m0n0wall log: BLOCK 14:45:27.888157 LAN 192.168.4.25 192.168.4.37, type echoreply/0 ICMP So the reply is being sent from the 5.0 subnet but is not being allowed to reach my workstation because the firewall is blocking it. Why is the firewall blocking it ? I hope the explanation of my network is clear, please ask if you require further clarification. Thank you.

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Setting up a network where packets are traced

- by Marcus

My situation is the following: I have an internet connection, which is shared between people. More or less obviously, people is using it to download illegal stuff. Since I'm the owner of the connection, I want to avoid being sued. I don't want to prevent the people from doing the things they want, but I want to be legally safe. Now, I have relatively little competences in network administration, so I was wondering: is it possible to setup a network, where the source and destination of the packets are logged? I would use this to prove, in case of lawsuit, that the traffic was coming from a given machine. if the idea is feasible, is there any wireless router on which I can install linux, where I can install the packet sniffer? how much space could the logs take (containing only the timestamp/source/destination), per GB of traffic? a very rough estimation would be very helpful. if a machine on my network is sending bittorrent packets to a certain IP, would this log be able to reflect the time, source ip and destination ip? I assume that obviously the torrent data would be encrypted and un-decryptable. Am I missing something? Is there a better strategy? Any pointer to documentation would be helpful as well - in that case, I would use this as starting point.

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High latency due to non-presence of a transit provider in my country

- by nixnotwin

My ISP, a state owned incumbent, buys bandwidth from different transit providers. Whenever it buys transits it announces only a specific prefix (in most cases a hitherto unused) through the new transit AS. For e.g. if it runs out of bandwidth, it buys bandwidth from a new transit and announces a new prefix through it, while the same prefix is not announced (or announced with lowest metrics, so that the routes are very rarely used) via the old transits which continue to provide bandwidth to it. I am a business customer, so I have a fiber based link to the ISP and a tiny subnet is given to me. The subnet which is provide to me is part of a prefix which is announced by the AS of a transit who, it seems, do not have a presence in my country. So when I do a trace the packets, when they leave my ISP's AS, they take about 275ms to reach the transit providers core router, which is located in USA (half the world away). Also for upstream traffic my ISP uses a transit provider (tier 1) who has a presence in my country. But the return path is always through the transit which is in USA. So, average latency is 400ms. All the users of other ISPs in my country discover my subnet via USA. Even the traffic from neighboring countries, from Europe (which is much nearer) follows the path via USA. Sites using CDNs also resolve to ips in USA. I have informed the ISP NOC about the issue and I have asked them to provide an ip subnet belonging to a prefix announced by a local transit (preferably a tier 1 transit provider) and I am waiting for a reply. My question: Is it a serious issue that I must follow up to get it resolved? When I compared the latency on other providers in my country, it is, in most cases, less than half of my ISPs latency. Why my ISP doesn't announce all its prefixes to all of its transit providers, so that the packets can take efficient and nearest routes to reach prefixes that originate within its network?

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How to place a virtual machine in DMZ?

- by Giordano

I have an Ubuntu 12.04 server running few virtual machines with KVM. I would like to expose some of these virtual machines on the internet, to make it possible for customers to test the products we're developing and make available other products for demo purposes. One of the server NICs is configured with a public IP. However before exposing anything on the web I would like to be sure that if one of the virtual machines get compromised, the attacker doesn't reach the rest of the hosts. What I would like to do is to put these virtual machines into a DMZ. These are the steps I'm planning to do: Create a tap interface in the virtualization host (let's say tap1) Create a bridge using tap1 and give it an IP in a subnet separate from the other hosts. Let's say 10.0.0.1 Attach the DMZ virtual machines to the bridge and configure their IP statically (10.0.0.2, 10.0.0.3, etc...) Using UFW, forbid any traffic from 10.0.0.0/24 to any of the internal hosts, allow the traffic from the internal hosts towards 10.0.0.0/24 and expose the virtual machines on the web using port forwarding. Do you think this setup is safe? Can you suggest any improvement or a better/safer approach? Thanks in advance!

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Virtualizing an Inline network appliance with VirtualBox (or VMWare)

- by Tzury Bar Yochay

My device, which is a Linux based IP in-liner is transparent to the network peripherals, that is, no IP address assigned to any of its interfaces. For the sake of the conversation, let's use ADSL connection as an example, while the device is inspecting the bi-directional traffic, the network is behaving same as if device was not there, attached to the wire (see Physical setup at the attached diagram). I wonder if I can enclosed that "device" within a Windows machine and have it operated virtually so it still seats inline between the ADSL router and the Windows netwroking interface by using virtual NICs, (or whatever their name is in windows), and inspecting the traffic, same as if it was on a separate physical device, the drawing under "Virtual Setup" in the attached diagram show what I am trying to achieve. Reading a bit on the VirtualBox docs, seems like binding the right side is relatively simple, perhaps I should have one network adapter set as Bridge Networking and VirtualBox will connect it to the physical NIC on the host machine, and network packets are exchanged directly, circumventing the host operating system's network stack (WinXP in my case). However, I have no idea how to achieve the left side of my diagram, which requires adding virtual NICs to windows and configure them correctly in a way to make that pipeline possible. I would appreciate any help. by the way, if that is not possible with VirtualBox but with other virtualization solution (e.g. VMWare), I would accept the other as well.

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Route through site-to-site VPN not working

- by Jonathan

I'm trying to set up a site-to-site VPN using RRAS on two 2K8r2 servers since yesterday. The connection is working at this point, but I can't get it to send traffic from one site to the other one. Set up: the set up is the same on both sites: the server is connected to a router that's connected to a modem. The routers act like a DHCP-server and assign IP addresses from the range subnet.21-subnet-.100. Both servers use a static IP address, subnet.11, and are set up as DMZ. Configuration: the servers are configured using the wizard to set up a site-to-site connection. This works with a demand-dial interface and a PPTP VPN connection. As mentioned, the VPN connection work properly. Problem: I can't get the servers to send the traffic for the other site, to be sent through the VPN connection. I added a static route on both server (home, office 1) and I can see the result in the IP routing table (home, office 1). I did this because the route didn't show up automatically. My guess is that this last step isn't right, for example because the routing table states "non demand-dial", which seems not correct. Home: Subnet: 10.0.1.0/24 Router: 10.0.1.1 Server: 10.0.1.11 (DMZ) DHCP: 10.0.1.21-10.0.1.100 RRAS DHCP: 10.0.1.101-10.0.1.150 Office 1: Subnet: 10.0.2.0/24 Router: 10.0.2.1 Server: 10.0.2.11 (DMZ) DHCP: 10.0.2.21-10.0.2.100 RRAS DHCP: 10.0.2.101-10.0.2.150 I hope someone has an idea to get this route working!

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IPTables Rule for Google Apps SMTP

- by XpresServers

I am trying to add iptables rule to allow traffic on ports 465 & 587 to google apps smtp servers. But I got not luck. My WHMCS installation works fine with google apps when I turn off iptables but iptables turn on itself again and email stop working. Please add rules to allow traffic from port 465 and 587. Following are my IPTables rules grabbed from /etc/sysconfig/iptables # Generated by iptables-save v1.3.5 on Fri Oct 5 01:33:52 2012 *filter :INPUT ACCEPT [2191:434537] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [2390:987151] :acctboth - [0:0] -A INPUT -j acctboth -A OUTPUT -p tcp -m multiport --dports 25,465,587 -m owner --gid-owner mailman -j ACCEPT -A OUTPUT -p tcp -m multiport --dports 25,465,587 -m owner --gid-owner mail -j ACCEPT -A OUTPUT -d 127.0.0.1 -p tcp -m multiport --dports 25,465,587 -m owner --uid-owner cpanel -j ACCEPT -A OUTPUT -p tcp -m multiport --dports 25,465,587 -m owner --uid-owner root -j ACCEPT -A OUTPUT -j acctboth -A OUTPUT -o eth0 -p tcp -m tcp --sport 587 -m state --state ESTABLISHED -j ACCEPT -A OUTPUT -o eth0 -p tcp -m tcp --sport 465 -m state --state ESTABLISHED -j ACCEPT <<IN THIS SPACE RULES ARE RELATED TO SPECIFIC IPS ONLY>> -A acctboth -i ! lo COMMIT # Completed on Fri Oct 5 01:33:52 2012 # Generated by iptables-save v1.3.5 on Fri Oct 5 01:33:52 2012 *nat :PREROUTING ACCEPT [196:12398] :POSTROUTING ACCEPT [191:15070] :OUTPUT ACCEPT [190:15010] -A OUTPUT -p tcp -m multiport --dports 25,465,587 -m owner --gid-owner mailman -j RETURN -A OUTPUT -p tcp -m multiport --dports 25,465,587 -m owner --gid-owner mail -j RETURN -A OUTPUT -d 127.0.0.1 -p tcp -m multiport --dports 25,465,587 -m owner --uid-owner cpanel -j RETURN -A OUTPUT -p tcp -m multiport --dports 25,465,587 -m owner --uid-owner root -j RETURN -A OUTPUT -p tcp -m multiport --dports 25,465,587 -j REDIRECT COMMIT # Completed on Fri Oct 5 01:33:52 2012 Thanks Hassan

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Load is 0, yet site crawls (sometimes). What gives?

- by Yegor

I have a ~1.5-2mil page views per day site running on 2 servers. One for mysql, other for everything else. Mysql box has a load of 3, frontend is usually 0.0-0.1. Both are dual quad core with 8GB ram running SAS drives in raid5. CPU is idle for majority of the time, iowait is non-existent. Im running nginx, memcache, and site is built on php. Half the time everything runs perfect, while at other times it lags something severe, when it takes 10-15 seconds for a page to load. Page execution time is always super low, but it seems to hang, waiting for something before it actually loads the page. Whats even more weird is that it only happens to 1 file on the site (but its the one thats most commonly accessed, that actually loads the content on the site). Other pages are super fast at all times, even when it takes 15 seconds to load actual content. I have nginx_stats plugin installed, and if I monitor it, the lag spikes happen when the write column starts going above 100, and it frequently does... all the way to 500-1000. It does so at totally random times... not when traffic is heavy... it can do this in the middle of the night, and work perfectly at 5pm when traffic is at its highest. Any ideas?

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Technology mash: is this possible?

- by Jon Story

I'm in the process of setting up my own DNS+hosting on a couple of VPS and my home machines, mostly for academic/learning purposes, but also for convenient accessing of my files, hosting my personal websites, private git repositories etc. I've got a main web server with DNS, and a slave DNS server. I've also got a couple of machines at home doing file hosting, video streaming and all that fun stuff. I'm intending to use my VPS's to provide myself with a dynamic DNS system so that I can point mydomain.com at my DNS servers, with home.mydomain.com going into my home network via a raspberry pi. HOWEVER.... I've not got access to the network infrastructure at home (rented accommodation with managed internet), so I can't forward the ports on the router to my own machines. As such, I'm wondering if it's possible to route all the traffic via an SSH/HTTP tunnel through one of the VPS? My plan is to have the raspberry pi provide a VPN into my home network. The raspberry pi uses SSH to connect to the VPS, and the VPS forwards any traffic to home.mydomain.com via the tunnel to the raspberry pi. Is this even possible, and how do I go about it? I don't mind getting my hands dirty with coding and low level tools, I'm just not sure where to start or what the best way to go about it is.

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Can't route specific subnet thru VPN in ubuntu

- by Disco

I'm having issues routing traffic thru VPN. Here's my setup I have 3 hosts, let's call them A, B and Z B and Z have a VPN connection in the 10.10.10.x SUBNET A and B have a direct connection in the 10.10.12.x SUBNET I want to be able to route traffic from A to Z, like : A <= 10.10.12.254 [LAN] 10.10.12.111 => B <= 10.10.10.152 [VPN] 10.10.10.10 => Z On host B, i have set up ip_forwarding : net.ipv4.ip_forward = 1 and routing on host B: [root@hostA: ~]# ip route 10.10.10.10 dev ppp0 proto kernel scope link src 10.10.10.152 10.10.12.0/24 dev eth1 proto kernel scope link src 10.10.12.111 10.10.10.0/24 dev ppp0 scope link 169.254.0.0/16 dev eth1 scope link routing on host A: [root@hostA: ~]# ip route 10.10.10.0 via 10.10.12.111 dev eth1 10.10.12.0/24 dev eth1 proto kernel scope link src 10.10.12.254 169.254.0.0/16 dev eth1 scope link default via 192.168.1.1 dev eth0 But still not able to ping 10.10.10.10 from host A. Any idea ? I'm pulling my hairs out.

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Linux: prevent outgoing TCP flood

- by Willem

I run several hundred webservers behind loadbalancers, hosting many different sites with a plethora of applications (of which I have no control). About once every month, one of the sites gets hacked and a flood script is uploaded to attack some bank or political institution. In the past, these were always UDP floods which were effectively resolved by blocking outgoing UDP traffic on the individual webserver. Yesterday they started flooding a large US bank from our servers using many TCP connections to port 80. As these type of connections are perfectly valid for our applications, just blocking them is not an acceptable solution. I am considering the following alternatives. Which one would you recommend? Have you implemented these, and how? Limit on the webserver (iptables) outgoing TCP packets with source port != 80 Same but with queueing (tc) Rate limit outgoing traffic per user per server. Quite an administrative burden, as there are potentially 1000's of different users per application server. Maybe this: how can I limit per user bandwidth? Anything else? Naturally, I'm also looking into ways to minimize the chance of hackers getting into one of our hosted sites, but as that mechanism will never be 100% waterproof, I want to severely limit the impact of an intrusion. Cheers!

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information about /proc/pid/sched

- by redeye

Not sure this is the right place for this question, but here goes: I'm trying to make some sense of the /proc/pid/sched and /proc/pid/task/tid/sched files for a highly threaded server process, however I was not able to find a good explanation of how to interpret this file ( just a few bits here: http://knol.google.com/k/linux-performance-tuning-and-measurement# ) . I assume this entry in procfs is related to newer versions of the kernel that run with the CFS scheduler? CentOS distro running on a 2.6.24.7-149.el5rt kernel version with preempt rt patch. Any thoughts?

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Only tunnel certain applications via OpenVPN

- by jinjin

Hi, I've purchased a VPN solution, it works correctly when I have "redirect-gateway def1" in the configuration file (routing all traffic through the VPN). However when I remove that line from the configuration file, I am still able to ping-out of the machine (ping -I tap0), however I cannot ping the IP assigned to the machine (it's a public ip), i get the error: Destination Host Unreachable. I only want to have certain applications sending traffic through the VPN tunnel (eg: ZNC, irssi), all of which i can select which IP they use. However they can't recieve any data, making the tunnel essentially useless to me when disabling redirect-gateway. Any ideas on how to allow specific applications use the tunnel, without of forcing everything to go through it? My configuration file is as follows: dev tap remote #.#.#.# float #.#.#.# port 5129 comp-lzo ifconfig #.#.#.# 255.255.255.128 route-gateway #.#.#.# #redirect-gateway def1 secret key.txt cipher AES-128-CBC The output of ifconfig -a when the tunnel is connected: tap0 Link encap:Ethernet HWaddr 00:ff:47:d3:6d:f3 inet addr:#.#.#.# Bcast:#.#.#.# Mask:255.255.255.255 inet6 addr: <snip> Scope:Link UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 RX packets:612 errors:0 dropped:0 overruns:0 frame:0 TX packets:35 errors:0 dropped:0 overruns:0 carrier:0 collisions:0 txqueuelen:100 RX bytes:25704 (25.1 KiB) TX bytes:6427 (6.2 KiB) EDIT: the Bcast:#.#.#.# (ifconfig) is different from route-gateway #.#.#.# (openvpn) if that makes any difference.

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esx5 debian VM vlan setup

- by Kstro21

i have a server with ESX5, have a switch with about 20 vlans, this is how setup the trunk port interface GigabitEthernet0/1/1 description ToOper port link-type trunk undo port trunk allow-pass vlan 1 port trunk allow-pass vlan 2 to 14 stp disable ntdp enable ndp enable bpdu enable then, i created a standar switch(sw1) using the vSphere Client, the VLAN ID is set to All (4095), i also created a VM with Debian 6, with a NIC connected to sw1, now, i want to configure this NIC for a selected group of vlans auto vlan10 iface vlan10 inet static address 11.10.1.0 netmask 255.255.255.224 mtu 1500 vlan_raw_device eth0 auto vlan14 iface vlan14 inet static address 11.10.1.65 netmask 255.255.255.248 mtu 1500 vlan_raw_device eth0 so, when i restart the network using /etc/init.d/networking restart, i got this error Reconfiguring network interfaces...SIOCSIFADDR: No such device vlan14: ERROR while getting interface flags: No such device SIOCSIFNETMASK: No such device SIOCSIFBRDADDR: No such device vlan14: ERROR while getting interface flags: No such device SIOCSIFMTU: No such device vlan14: ERROR while getting interface flags: No such device Failed to bring up vlan14. done. this is just part of the error, so, my questions is: is this possible?, i mean, what i'm trying to achieve using ESX Virtual Machines, VLANS, etc is this a Debian problem? can be solved? i've read about a file named z25_persistent-net.rules in Debian but it doesn't exist in my installation. in the In the vSphere Networking for ESX5 guide, you can read: If you enter 0 or leave the option blank, the port group can see only untagged (non-VLAN) traffic. If you enter 4095, the port group can see traffic on any VLAN while leaving the VLAN tags intact. So, in theory, it should work, right? Hope you can help me up with this one Thanks

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Linux port-based routing using iptables/ip route

- by user42055

I have the following setup: 192.168.0.4 192.168.0.6 192.168.0.1 +-----------+ +---------+ +----------+ |WORKSTATION|------| LINUX |------| GATEWAY | +-----------+ +---------+ +----------+ 192.168.150.10 | 192.168.150.9 +---------+ | VPN | +---------+ 192.168.150.1 WORKSTATION has a default route of 192.168.0.6 LINUX has a default route of 192.168.0.1 I am trying to use the gateway as the default route, but route port 80 traffic via the VPN. Based on what I read at http://www.linuxhorizon.ro/iproute2.html I have tried this: echo "1 VPN" >> /etc/iproute2/rt_tables sysctl net.ipv4.conf.eth0.rp_filter = 0 sysctl net.ipv4.conf.tun0.rp_filter = 0 sysctl net.ipv4.conf.all.rp_filter = 0 iptables -A PREROUTING -t mangle -i eth0 -p tcp --dport 80 -j MARK --set-mark 0x1 ip route add default via 192.168.150.9 dev tun0 table VPN ip rule add from all fwmark 0x1 table VPN When I run "tcpdump -i eth0 port 80" on LINUX, and open a webpage on WORKSTATION, I don't see the traffic go through LINUX at all. When I run a ping from WORKSTATION, I get this back from some packets: 92 bytes from 192.168.0.6: Redirect Host(New addr: 192.168.0.1) Vr HL TOS Len ID Flg off TTL Pro cks Src Dst 4 5 00 0054 de91 0 0000 3f 01 4ed3 192.168.0.4 139.134.2.18 Is this why my routing is not working ? Do I need to put GATEWAY and LINUX on different subnets to prevent WORKSTATION being redirected to GATEWAY ? Do I need to use NAT at all, or can I do this with routing alone (which is what I want) ?

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Centos iptables configuration for Wordpress and Gmail smtp

- by Fabrizio

Let me start off by saying that I'm a Centos newby, so all info, links and suggestions are very welcome! I recently set up a hosted server with Centos 6 and configured it as a webserver. The websites running on it are nothing special, just some low traffic projects. I tried to configure the server as default as possible, but I like it to be secure as well (no ftp, custom ssh port). Getting my Wordpress to run as desired, I'm running into some connection problems. 2 things are not working: installing plugins and updates through ssh2 (failed to connect to localhost:sshportnumber) sending emails from my site using the Gmail smtp (Failed to connect to server: Permission denied (13)) I have the feeling that these are both related to the iptables configuration, because I've tried everything else (I think). I tried opening up the firewall to accept traffic for ports 465 (gmail smtp) and ssh port (lets say this port is 8000), but both the issues remain. Ssh connections from the terminal are working fine though. After each change I tried implementing I restarted the iptables service. This is my iptables configuration (using vim): # Generated by iptables-save v1.4.7 on Sun Jun 1 13:20:20 2014 *filter :INPUT ACCEPT [0:0] :FORWARD ACCEPT [0:0] :OUTPUT ACCEPT [0:0] -A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT -A INPUT -p icmp -j ACCEPT -A INPUT -i lo -j ACCEPT -A INPUT -p tcp -m tcp --dport 8000 -j ACCEPT -A INPUT -p tcp -m tcp --dport 80 -j ACCEPT -A INPUT -p tcp -m tcp --dport 465 -j ACCEPT -A INPUT -j REJECT --reject-with icmp-host-prohibited -A FORWARD -j REJECT --reject-with icmp-host-prohibited -A OUTPUT -m state --state RELATED,ESTABLISHED -j ACCEPT -A OUTPUT -o lo -j ACCEPT -A OUTPUT -p tcp -m tcp --dport 8000 -j ACCEPT -A OUTPUT -p tcp -m tcp --dport 465 -j ACCEPT COMMIT # Completed on Sun Jun 1 13:20:20 2014 Are there any (obvious) issues with my iptables setup considering the above mentioned issues? Saying that the firewall is doing exactly nothing in this state is also an answer... And again, if you have any other suggestions for me to increase security (considering the basic things I do with this box), I would love hear it, also the obvious ones! Thanks!

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Configuring IE to resolve DNS at the proxy rather than locally.

- by dankilman

With the intention of tunneling web traffic through an SSH connection, the following has been done: I've manually configured a PAC file in IE7 in the LAN Settings dialog. I've verified that traffic is routed through my SSH tunnel that is setup for SOCKS5 dynamic port forwarding. I see that IE7 is always trying to resolve the name locally first. What I'm looking for is the ability to have the DNS name resolved at the proxy, rather than locally by the browser. There's a setting in Firefox that specifies DNS remote resolution, and Safari does it automatically. I've verified correct operation for these 2 other browsers. It would be nice if I could get IE to work also. This is for reference so you could understand where does the question originate from. Notice: The question was actually found by the help of google but with no answers available. Considering how it is exactly my question I figured I should just copy/paste over here because I don't think I could describe any better (there is a small introduction though).

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Tracking a subdomain serately within the main domain account [closed]

- by Vinay

I have a website, for example: xyz.com and info.xyz.com. I created a profile for xyz and tracking is good. I added a new profile for info.xyz.com in xyz.com. Analytics tracking for info.xyz.com is showing traffic from both xyz.com and info.xyz.com. How do I change to show only info.xyz traffic in the info.xyz.com profile. I used the following code: Analytics code for xyz.com domain: <script type="text/javascript"> var _gaq = _gaq || []; _gaq.push(['_setAccount', 'UA-xxxxxx-x']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); </script> Analytics code for info.xyz.com <script type="text/javascript"> var _gaq = _gaq || []; _gaq.push(['_setAccount', 'UA-xxxxxx-x']); _gaq.push(['_setDomainName', 'xyz.com']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); </script>

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I need a reverse proxy solution for SSH

- by Bond

Hi here is a situation I have a server in a corporate data center for a project. I have an SSH access to this machine at port 22.There are some virtual machines running on this server and then at the back of every thing many other Operating systems are working. Now Since I am behind the data centers firewall my supervisor asked me if I can do some thing by which I can give many people on Internet access to these virtual machines directly. I know if I were allowed to get traffic on port other than 22 then I can do a port forwarding. But since I am not allowed this so what can be a solution in this case. The people who would like to connect might be complete idiots.Who may be happy just by opening putty at their machines or may be even filezilla.I have configured an Apache Reverse Proxy for redirecting the Internet traffic to the virtual machines on these hosts.But I am not clear as for SSH what can I do.So is there some thing equivalent to an Apache Reverse Proxy which can do similar work for SSH in this situation. I do not have firewall in my hands or any port other than 22 open and in fact even if I request they wont allow to open.2 times SSH is not some thing that my supervisor wants.

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Routing and authenticating all access through squid

- by Knight Samar

Hi, I want to route all Internet access in my network through a Squid proxy server and authenticate and log all users. I want this to be a client-independent setting so that no one needs to do anything on their browsers or machines. I have set my network gateway as the proxy server so that all traffic will be sent to it. I have done this using options in DHCP server. Now I tried using squid as a transparent proxy, but then it won't authenticate in that mode. I tried using iptables to route all traffic to port 3128 but it won't popup the authentication dialog box from SQUID. I tried telling DHCP to give WPAD to all clients by placing a WPAD file on a webserver containing the following for automatic proxy configuration on clients: Changes in dhcpd.conf option wpad code 252 =test; option wpad "\n\000"; option wpad "http://192.168.1.5/wpad.dat\n"; The WPAD file: function FindProxyForURL(url,host) { return "PROXY squid-server-ip-address:3128 ; DIRECT "; } But the browsers (different versions of Firefox and IE) seem to ignore it. :( What should I do ?

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DHCP Relay setup in ubuntu server

- by jerichorivera

I have a network appliance (QNO) that works as traffic load balancer and dhcp server. I would like to add a linux server in between the network appliance and the client computers. The linux server will be used to monitor bandwidth usage. My problem is I still want DHCP to be served by the network appliance so that load balancing will still work efficiently. We are afraid that if we setup the linux server as the DHCP server the network appliance will not be able to load balance the traffic if it only sees the linux server as a single client connecting to it. I've been searching all over for a tutorial on how to setup DHCP relay but have not found any. How do I setup DHCP relay on my linux server given there are two NICs attached to it, one connects the linux server to the network appliance and the other connects the linux server to the client computers. EDIT Router (DHCP) ---- [eth0] Linux Server (Relay agent) [eth1] ----- PC (network) Router IP is 192.168.0.100 eth0 is on DHCP eth1 is static 192.168.2.11 (if I need to change this I can) Tried to do dhcrelay -i eth1 192.168.0.100, but the PC was not getting any DHCP lease from the DHCP router. I might be missing something here.

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How do you get AWS VPC EC2 instances to be able to see the AWS APIs?

- by Peter Mounce

We're spinning up infrastructure inside of an AWS VPC via CloudFormation. We're using auto-scaling groups to bring up VPC-EC2 instances (so, we don't bring up instances directly; ASGs manage that). Inside of a PVC, EC2 instances only have a private IP; they cannot see the outside world without further work. When these instances spin up, we have some bootstrap tasks that require talking to the various AWS APIs. We also have some ongoing tasks that require AWS API traffic. How are you tackling this apparent chicken-egg problem? We've read about: NAT instances - but don't like this so much because it's another layer to our stack. assigning elastic-IPs to each VPC instance that needs to talk - but a) they all do, and b) since we're using ASGs, we don't know which instances to assign EIPs to at provision-time, and c) we'd need to set up something to monitor those ASGs and assign EIPs when instances are terminated and replaced spinning up an instance (actually, a load-balanced pair, probably spanning AZs) to act as an AWS-API proxy for all API traffic I guess I'm wondering whether there's some kind of back-door we can open that allows our VPC EC2 instances access to the AWS API endpoints, but nothing else, for cheap-complexity setup, that doesn't add another network-hop layer to our infrastructure for serving requests.

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VPS goes slow at more than 20 users online at the same time

- by hachiari

I have 512 MB VPS (brustable to 1GB) Somehow, the site goes slow when there are about 10 users, and becomes impossible to load at 20 users online at the same time. I wonder what could be the problem for this. The bandwidth connection of the VPS is 1Gbps. Here is some settings in my VPS: KeepAlive Off <IfModule prefork.c> StartServers 7 MinSpareServers 7 MaxSpareServers 10 ServerLimit 64 MaxClients 64 MaxRequestsPerChild 0 </IfModule> my.cnf settings - calculated Max Memory 300MB Output from UNIXBENCH INDEX VALUES TEST BASELINE RESULT INDEX Dhrystone 2 using register variables 376783.7 13429727.4 356.4 Double-Precision Whetstone 83.1 1137.5 136.9 Execl Throughput 188.3 1637.4 87.0 File Copy 1024 bufsize 2000 maxblocks 2672.0 148868.0 557.1 File Copy 256 bufsize 500 maxblocks 1077.0 79430.0 737.5 File Read 4096 bufsize 8000 maxblocks 15382.0 1410009.0 916.7 Pipe Throughput 111814.6 4419722.0 395.3 Pipe-based Context Switching 15448.6 561505.1 363.5 Process Creation 569.3 10272.7 180.4 Shell Scripts (8 concurrent) 44.8 514.3 114.8 System Call Overhead 114433.5 3537373.8 309.1 ========= FINAL SCORE 295.0 I am afraid that the VPS company limit the number of connection to the VPS... is it possible? The server is in Japan, but the site has global traffic (some of the traffic are from countries with low speed connection). Could this be the problem? This is a serious problem :( my site just cant grow if this keeps on happening... please tell me if you have any idea. Thank You, Bryant

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Apache local verses external (domain)

- by Jessy Houle

I have an Apache server running on Ubuntu server 10, using Passenger for Ruby on Rails. I have configured my site under the sites-enabled directory of Apache and can hit the server with an internal IP address (192.168.X.X) and the site comes back as expected. However, whenever I try to hit the site externally, either through the domain name or the IP address tied to the domain name, the site will not come back. I have a router in the middle with a static IP address, with Port Forwarding turned on (forwarding 80/443) to the server and I'm quite confident the issue isn't there. In fact, I even DMZed to the Ubuntu Server just to make sure. Also, all router firewall options have been turned off. So here is the question... Is there something else I have to do with Ubuntu server to allow externally requested port 80 traffic? Otherwise, is there some settings that need to be set in Apache to allow domain or external IP address port 80 traffic through? I'm pretty new to Apache, so, please take it a bit easy on me :-) Thank you for your responses. -Jessy Houle

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IP to IP forwarding with iptables [centos]

- by FunkyChicken

I have 2 servers. Server 1 with ip 1.1.1.1 and server 2 with ip 2.2.2.2 My domain example.com points to 1.1.1.1 at the moment, but very soon I'm going to switch to ip 2.2.2.2. I have already setup a low TTL for domain example.com, but some people will still hit the old ip a after I change the ip address of the domain. Now both machines run centos 5.8 with iptables and nginx as a webserver. I want to forward all traffic that still hits server 1.1.1.1 to 2.2.2.2 so there won't be any downtime. Now I found this tutorial: http://www.debuntu.org/how-to-redirecting-network-traffic-a-new-ip-using-iptables but I cannot seem to get it working. I have enabled ip forwarding: echo "1" > /proc/sys/net/ipv4/ip_forward After that I ran these 2 commands: /sbin/iptables -t nat -A PREROUTING -s 1.1.1.1 -p tcp --dport 80 -j DNAT --to-destination 2.2.2.2:80 /sbin/iptables -t nat -A POSTROUTING -j MASQUERADE But when I load http://1.1.1.1 in my browser, I still get the pages hosted on 1.1.1.1 and not the content from 2.2.2.2. What am I doing wrong?

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