Routing (in IP-based networks) is the process of selecting paths in a network along which to send network traffic.

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Sniffing packets through router

I would like to create a system like this. The user would connect through a wifi network which would reroute all http requests and responses through the network card on a computer thus allowing that ...
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477 views

Redirect ALL packets from eth1 & eth2 through a SOCKS proxy

Is there a way to redirect all traffic, UDP and TCP, coming to and from eth1 and eth2 through a SOCKS proxy (Tor) which then passes it through eth0? eth0: Internet in - leads to the main router, then ...
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1answer
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How do I route traffic through specific interface for a specific process

I have a script that runs from cron every 15 minutes. The script is meant to ping my DNS server to update a dynamically changing IP. I want this script to ping through the wlan interface and not the ...
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2answers
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Xen, bridge and multiple IPs on CentOS

There's a new server that is assigned 5 IP addresses. I want to use Xen to run several VMs with various services. This is my first attempt to install Xen, I use this tutorial as a guideline. Stuck ...
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1answer
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Adding two default gateways in Debian interfaces file

This is my interfaces file: auto eth0 iface eth0 inet static address 192.168.1.10 netmask 255.255.255.0 gateway 192.168.1.1 auto eth1 iface eth1 inet static address 192.168.2.10 ...
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2answers
552 views

Block specific IP from accessing gateway

Suppose you are on linux internet gateway/router. What would you do to block a client with specific IP using bash script. I prefer something like ./block_client.sh 192.168.1.123 to block and ...
3
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2answers
880 views

Use eth interface to connect to a router and wlan for the internet

I am currently trying to configure a router to which I connect to (to its web interface) using an Ethernet cable through the eth0 interface. That router doesn't have access to the internet. Now, I ...
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3answers
173 views

What happens to local LAN traffic on linux to non-loopback addresses?

One thing I've never quite understood on Linux is what happens to local traffic that isn't directed at loopback. For example, given the following network setup: [root@pe-323-master ~]# ifconfig eth0 ...
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1answer
880 views

Internet routing between wlan0 and ppp0?

On my Debian Linux device, I have a USB-modem that is connected to the Internet. Its interface name is ppp0. I also have a USB-wireless adapter, where I am hosting a Access Point. Its interface name ...
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1answer
969 views

Share Internet Connection from computer to new router

On my linux computer I have an external wlan adapter which is connected wirelessly to internet (an access point). Now I want to connect my linux computer via ethernet cable to a new ddwrt router. This ...
3
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1answer
637 views

Routing through iptables

I have this vpn client that touches the routing table and then keeps watching it to exit if it gets touched. It is the kind of setup needed for an endpoint, such as a laptop. I want to use a small ...
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2answers
692 views

Need help with routing

I have set up a Ubuntu server, that I want to use as a router for my local office. The problem is, that I want to make 2 VPN connections, to remote branches, and then I want to route all traffic to ...
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1answer
593 views

Routing Tables: What is the effect of the RTF_IFSCOPE flag?

(Related to this question I posted a while ago on apple.stackexchange.) What is the difference between the following two routing table entries: default E.F.G.H UGSc 0 ...
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1answer
606 views

What is the interface scope (global vs. link) used for?

Routing table entries have an attribute scope. I would like to know how the change from global to link (or the other way round) affects the network system.
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1answer
169 views

Linux: How to auto-configure IP routing based upon ping results

I've got a linux server with two possible connections to the net: one is a slow, high-latency cellular modem (ppp0), and the other is through fast wifi->broadband (wlan0). The problem is that the ...
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2answers
459 views

Linux: Is there a IPv6 equivalent to the IPv4 kernel option accept_local?

Since linux kernel >= 2.6.33 the kernel option "accept_local" can be modified: /proc/sys/net/ipv4/conf/${interfaceID}/ accept_local - BOOLEAN Accept packets with local source addresses. ...
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1answer
417 views

Simplest way to set up multiple subdomains to separate VMs running on single host

Problem: I´m planning to set up several virtualized centos, rhel or ubuntu guest machines on a single centos host server (most likely using KVM). Each guest VM is running an instance of a webapp + ...
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41 views

Route VPN traffic through different proxies

I want to setup VPN server and route (based on my routing algorithm) all traffic through different proxy servers. Let's say I have one host, with many users, connected to my VPN. I want to route all ...
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0answers
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Packets do not cross IP tables Postrouting when originating from an external IP

I'm trying to reflect traffic from the internet to an internal device that I only want to have local access. I have a host in my DMZ that I'm trying to DNAT traffic to this internal device, and SNAT ...
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1answer
88 views

How does Linux handle 2 identical destinations in its routing table?

I have this is my routing table (in that order): 10.3.68.0/22 via 172.16.100.9 dev vlan4 10.3.68.0/22 dev eth3 proto kernel scope link src 10.3.69.254 eth3 has ip 10.3.69.254/22. Why does ...
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1answer
230 views

Creating a private network for internal VMs

I am trying to configure a private network for use with my Xen VMs, in addition to the public network in use by another of the VMs (VM1, which has its own public IP). So far, I have the public side ...
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1answer
116 views

What are the requierements to sniff UDP packets in a Wireless Ad-Hoc network?

In a wireless Ad-Hoc network, I have two computers which communicates in UDP together from 192.168.1.3 to 192.168.1.5 I have a third computer (192.168.1.6) which wants to listen to the packets which ...
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1answer
341 views

Alternative to mrouted for DVMRP on Debian Squeeze

I need to implement DVMRP protocol to route multicast over Openvpn (tun) connection for some old 3Com NBX phones. I use Debian squeeze so mrouted is not available (obsolete). What can I use ...
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2answers
576 views

Policy routing with load balanced ppp connections

This my setup using Debian 6.0. 6. It's role is a proxy server and a load balancer using eight 3G modems. Whenever a ppp connection dials it takes over the default gateway which is ok but it also ...
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Traffic getting routed through Apache

for some reason, certain outgoing traffic on my server gets routed to the apache webserver i am running. this problem just started happening. i have the webserver set up to use vhosts, the webserver ...
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1answer
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How do I configure OpenVPN as a Gateway client for Witopia?

I have the following setup: Witopia SSL account Synology 409 NAS (with OpenVPN and Apache etc) PS3 Mac Apple AirPort router (configured for NAT) Locked IPT-box (using DHCP and NAT traversing) ...
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2answers
602 views

What does my router need to act as a name server for my home network?

I am happily using an old PC as a router. Two network cards, Debian wheezy, NAT, ... everything just fine. My home network uses static IPs, which I am also happy with. However, every box on my home ...
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2answers
1k views

Use a specific interface for a specific destination subnet (source IP setting)

I am looking for some sort of routing trickery to set a specific source IP: Local machine has two IPs; Eth1: 192.168.0.1 Eth1:2 192.168.0.2 Default gateway is 192.168.0.254 via Eth1 Remote subnet ...
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2answers
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How is the loopback network interface implemented?

The loopback network interface "is a virtual network device implemented entirely in software," according to another question on Unix.SE. But how is this implementation actually accomplished, and how ...
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2answers
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CentOS: Sharing WLAN for internet access

I have installed CentOS 6.2 on HP Proliant server. I want to share my USB wireless internet (Tata photon +). I am able to start internet on my server, but when I enable my LAN, I don't have internet ...
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2answers
389 views

Primary network interface in Linux

I have a server box with two interfaces. One of the interfaces is connected to the internal network, another - to external. I have assigned IP 192.168.1.200 to internal interface (eth0). I have some ...
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Different sites on different interfaces using link aggregation

I read about Ubuntu Bonding and how it allows to bond multiple connections to get several advantages. My requirements is this : I want two different interfaces at a time (A wifi and other Ethernet) ...
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3answers
225 views

Detect which interface traffic to an IP address goes through

I'm making an script, and I need to detect in what interface is the traffic of an IP going through. This is because in the arch, an IP address is attended only for one of four NIC's, but can be any of ...
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4answers
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How do I route web requests into my private network depending on the domain in the url?

Scenario: Due to limited number of IPs, several domains are resolved into the same IP address. However, these domains may not all run on the same webserver, VM, or even dedicated machine. Therefore, ...
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3answers
107 views

Bridge/Router with custom logic

I've a Linux box with 3 network adapaters, which I'd like to configure as follow: Adapter A is connected to computer A Adapter B is connected to computer B Adapter C is connected to the Internet. ...
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1answer
92 views

iptables routing incoming IP to another destination IP question

I have a test setup: server1:1.1.1.1 server2:2.2.2.2 client: 3.3.3.3 I'm trying to have client IP 3.3.3.3 do a HTTP request from the 1.1.1.1 server. However I want the 1.1.1.1 server to pass this ...
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1answer
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mutliple default gateways for alias interfaces (SOLVED)

Alias interfaces defined in /etc/network/interfaces cannot have multiple default gateways. Unfortunately I would like to use the same interface to access 2 differents nets, and I need to define 2 ...
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1answer
236 views

How do I prevent my hostapd access point from pretending to route to the Internet?

I have a nice little iMX6 (an ARM CPU) board running Linux kernel 3.0.35 with hostapd 0.7.3. Setting up the wireless interface as an access point works fine but clients think they can be routed ...
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1answer
604 views

Route only ssh traffic through VPN

Is it possible to route a computer's SSH service through a VPN connection but allow ALL other data to exit through the WAN address? What sort of iptables magic needs to be done to accomplish this? ...
2
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1answer
233 views

Linux nat/iptables configuration for a chain of peer-to-peer links

I have an experimental setup, of 4 Linux (CentOS) machines: All 4 machines are internally connected using different networks and can ping eachother directly connected interfaces. However only PC4 ...
2
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1answer
171 views

Make a linux network device a router

I am developing an IPv6 network device driver. It should behaviors like a router, i.e. send router advertisement regularly. But now my device is working like a node, send router solicitation. What ...
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1answer
249 views

PPTP server with NIC aliases

I have set up a VPN on a VPS Server using PPTP. I have one NIC with two aliases. eth0 eth0:1 eth0:2 The 3 interfaces have public addresses. eth0 is a French IP, eth0:1 is UK, and eth0:2 is ...
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4answers
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Make nslookup use specific interface

On my computer I have two network cards. Both are using different Internet Providers service. Both Internet service provider have different DNS server and their IP address are known to me. I want to ...
2
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1answer
891 views

Routing private network to internet via 2 gateways

I have the current set up for an embedded environment: Embedded Target (192.168.0.200) -----> Virtual Machine (VMWare) (2 NIC's - 192.168.0.2 (Target Port) and 192.168.49.69 (NAT Port to host)) ...
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1answer
622 views

Multiple VPN connetions, routing based on country

I want to set up a couple of VPN connections to two different countries, A and B, on my Ubuntu Server. Then I would like to set up rules based on GeoIP to determine which VPN connection should be used ...
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1answer
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Static route in Centos 6

Here is my route -n output: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 192.168.122.0 0.0.0.0 255.255.255.0 U 0 0 ...
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use iptables to allow incoming connections to some computer on port XYZ?

This is what I have: iptables -i em1 -A INPUT -j ACCEPT -p tcp --dport 9001 -v. If I want to accept incoming connections on port 9001 at this (127.0.0.1, or on the network 192.168.1.143) address, ...
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1answer
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Find connections per ip on an OpenWRT router?

How can I list the number of connections per client on the FORWARD chain of an OpenWRT router? I know how to list the number of connections per IP address on the router: netstat -ntu | tail -n +3 | ...
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1answer
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Limit the max connections per IP using OpenWRT?

Would the following iptables command on an OpenWRT router assure that no one client has more than 50 active connections? $ iptables -I FORWARD -m connlimit --connlimit-above 50 -j REJECT ...
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1answer
252 views

Forwarding packets from loopback interface with policy-based routing

I have the following iptables rule: iptables -t mangle -A PREROUTING -p udp -m udp --dport 10000 -j MARK --set-xmark 0x4/0xffffffff which sets fwmark 4 on all udp packets with destination port ...