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

learn more… | top users | synonyms

4
votes
2answers
1k views

Separate Network Traffic on Two Network Interfaces

I am not an R&S professional, so much of that realm of computing escapes me. Could you lend your expertise in helping understand how to go about configuring the separation of network traffic on ...
4
votes
2answers
748 views

Redirecting loopback traffic through a router

For some tests purposes, I am running multiple socket-based applications on one machine and want to simulate "real" network conditions between them. I thought the simplest would be to redirect all ...
4
votes
1answer
2k 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 ...
4
votes
2answers
190 views

Port Routing/DNS for individual program

Background Flickr has closed its http api leaving an https only api. My favourite uploader (the official Flickr Uploadr version 2.5 running under wine) is no longer maintained, so this change broke ...
4
votes
2answers
677 views

Send traffic to self over physical network on Ubuntu

I have a dual port ethernet NIC and let's say I have connected both ports in a loop and assigned the following IPs to the 2 ethernet interfaces: eth2 -> 192.168.2.1 eth3 -> 192.168.3.1 I want to ...
4
votes
1answer
1k views

How to set up ssh server with VPN tunnel? (Policy routing for sshd service)

It's difficult to me to explain in words, so I made diagrams. In short, I want this to work: Basically I want to be able to connect from my laptop [A] to my desktop [B] via ssh, and run terminal ...
4
votes
2answers
295 views

Is it possible to set-up a VPN in such a way that I disconnect from the Internet if it goes down?

How can I set-up a VPN so I loose connection to the Internet if it goes down? I use Ubuntu and have used the network-dialog to use a VPN; but if the VPN goes down, it just switches to the non-VPN ...
4
votes
1answer
700 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 + ...
4
votes
1answer
940 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 ...
4
votes
3answers
4k views

Send duplicate packets over two Internet connections

I need to duplicate an RTP stream over two different (non-reliable) Internet connections. On the receiver side, I will probably run a custom program that will use a buffer and rebuild the stream ...
4
votes
1answer
720 views

Fix “Route hash chain too long” without restart

On our production server (ubuntu 12.04, 3.2.0-63 kernel) routing cache reached its capacity. Modifying rhash_entries is out of the question, since it is a kernel boot param, and we can not restart the ...
4
votes
1answer
2k views

How to open VPN connection inside other VPN connection under Linux/Ubuntu

Is it possible to have two VPN connections on top of each other under Ubuntu? Scenario: My organization is quite large and has its own large network. Each group inside the organization has its own ...
4
votes
1answer
137 views

putting extra hops into traceroute6 on OpenBSD

I'm running OpenBSD, or maybe FreeBSD. I don't have lots of IPv4 addresses to waste, but who doesn't have a few billion of IPv6 ones? How do I add some extra IPv6 hops to a traceroute6, around pf(4) ...
4
votes
1answer
455 views

Throughput test setup with two local Ethernet interfaces

I'm currently testing the routing performance of a hardware device (DUT - Device Under Test) with the following setup (all addresses start with 192.168.): eth0 (29.2) <---> eth1 (29.1) eth2 ...
4
votes
1answer
2k views

multigateway routing for specific src port

I have two gateway to access internet, somehow I want to load balancing it, so far its working, but some connection or service need persistent gateway IP to be used, so the client should never change ...
4
votes
1answer
1k views

Why is this static route not taking effect?

Original Question I am running Ubuntu and network manager. I have two different interfaces, eth0 and eth1. Network manager has (as far as I can tell) correctly added this manual route: ~$ ip route ...
4
votes
2answers
751 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 ...
4
votes
1answer
2k views

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) ...
3
votes
1answer
197 views

Local DNS Server Refuses to Ask itself for DNS

I am running Debian 7 and have set up a DHCP and DNS server. Everything is working nicely, except for the server itself not following the DNS entries in BIND. The problem is that /etc/resolv.conf is ...
3
votes
4answers
2k views

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 ...
3
votes
2answers
2k 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 ...
3
votes
2answers
2k views

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 ...
3
votes
2answers
858 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
votes
2answers
96 views

Linux static routing : Ping a private network(Network Diagram Attached)

In the Network Diagram above my aim is to ping 192.168.20.20 from System A. I do not want to configure the router. For that to happen All the traffic to 192.168.20.0/24 should be first forwarded ...
3
votes
1answer
182 views

add route in Linux if sub-net, where gateway is situated, is not configured

I have a PC which has 192.168.1.1/24 configured to eth0 interface. Now if I try to add routes via 10.10.10.254, the ip utility reports that No such process: root@PC:~# ip neigh add 10.10.10.254 ...
3
votes
1answer
652 views

Use two NICs for different subnets

In my office I have use a system with two network cards. I want to use both at same time. I have four subnets in my LAN. I want to route two subnets (192.168.2.0 and 192.168.4.0) through eth0 and ...
3
votes
2answers
3k 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 ...
3
votes
1answer
5k views

multiple 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 different nets, and I need to define 2 ...
3
votes
1answer
2k 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
votes
1answer
88 views

PPTP VPN not working with Linux router

ORIGINAL: I've just switched from an old Linux install (Debian squeeze) to a new one (Linux Mint 17.3) for my router (I am using a full desktop PC with a Linux install as my router). The Linux PC ...
3
votes
1answer
1k views

OpenConnect: Setting default routes

I'm trying to use OpenConnect to connect to my company's Cisco VPN (AnyConnect) The connection seems to work just fine, what I'm not understanding is how to set up routing. I'm doing this from the ...
3
votes
3answers
472 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 ...
3
votes
1answer
919 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 ...
3
votes
2answers
858 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 ...
3
votes
1answer
128 views

How to create an internal multipath gateway

Basically trying to bend bridging and NATing to my will with quite a unique project. I've simplified what I'm doing below (VM=Kali virtual machine for testing): ZoneX's are network namespaces, ...
3
votes
1answer
469 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 ...
3
votes
1answer
2k views

How do I route different users over different OpenVPN tunnels in Linux?

The setup: I have multiple, static-key OpenVPN client/server configurations, labeled "client1", "client2", and "client3" with server/client IPs 10.10.1.1/10.10.1.2, 10.10.2.1/10.10.2.2, and ...
3
votes
2answers
576 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. ...
3
votes
0answers
29 views

No “unreachable” response for an outgoing TCP connection when using fwmark and policy routing

I would like to route locally-generated traffic: to a TCP port "A" of host "H" via the interface "A", to a TCP port "B" of host "H" via the interface "B". Interface "B" is sometimes unavailable. ...
3
votes
0answers
16 views

Routing policy is not working

I have an Access Point with OpenWrt. On other host of the same LAN there is a squid (IP Address 192.168.80.148). I'd like to route packages with destination port 80 to 192.168.80.148. So I have ...
3
votes
0answers
123 views

iptables and ip forwarding for failover

hi i have an ethernet nic interface with 4 additional virtual interfaces (failovers) all configured with public ip4 (IP-1 to IP-5) / netmask 255.255.255.255 / broadcast addr same as ip: eth0 ...
3
votes
0answers
240 views

Debian 8 : where are default static routes set?

i'm facing a strange problem with my newly installed Debian 8 box : default static routes are missing the 0.0.0.0 destination route. $ sudo route -n Kernel IP routing table Destination Gateway ...
3
votes
1answer
89 views

Routing on per application basis

I'm using a proprietary VPN client on my Ubuntu Linux work station (Astrill) which support several types of VPNs. One of these VPN types is OpenVPN, which creates a virtual interface tun0 when ...
3
votes
0answers
603 views

About tun2socks (BadVPN) SOCKS proxy

I am not very experienced with socks proxy. Recently I found the tun2socks. If you open the link, in the 1st paragraph it says : It implements a TUN virtual network interface which accepts all ...
3
votes
0answers
72 views

Linux Routing Question

I was wondering how it would be possible to have multiple IPv6 default gateways on CentOS linux. I currently have two interfaces with IPv6 (venet0 and tb0), both with different blocks routed to them. ...
3
votes
0answers
527 views

Bridge interface - add default route

I used to connect my ubuntu 14.04 laptop on office network via eth0 and the route table gets updated with the office network gateway ip in auto mode. Now, i changed my /etc/network/interfaces ...
3
votes
1answer
282 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 ...
3
votes
0answers
163 views

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 ...
3
votes
1answer
152 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 ...
3
votes
1answer
1k 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 ...