1
vote
0answers
40 views

Essential tasks of a routing daemon in Linux [closed]

What I have understood so far from some software router projects already there (e.g. bird), there are some essential subtasks for routing in Linux. Task 1: Get a routing table first (using ip route ...
2
votes
1answer
45 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 ...
2
votes
0answers
15 views

Set up a failover route when remote host unreachable [migrated]

I have a Debian Wheezy server tunned by Xivo (let's named it A), this server has 2 interfaces: eth0 and eth1 There are no default gateway and only few server are statically reached from A. eth0 have ...
1
vote
0answers
20 views

ip route match multiple fields

I have a Linux machine set up to forward IPv4 packets. I'm looking to do this: if packet matches both source and destination, forward to GW X. How do I specify the source field? Do I need to use ...
1
vote
2answers
95 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 ...
0
votes
1answer
63 views

routing based on source IP [closed]

Is it possible to configure routing based on source ip? For example, if I have source IP 10.0.0.0, then all the traffic will go via the specific interface or would be sent to specific default gateway. ...
5
votes
1answer
127 views

Skip routing via `lo` interface for outgoing packets

Introduction I have following load balancing configuration: 10.0.1.31 - lb 10.0.1.35 - virtual IP 10.0.1.32 - node1 (tomcat + mysql) 10.0.1.33 - node2 (tomcat + mysql) I'm using keepalived which ...
0
votes
0answers
62 views

Linux routing table entry disappears

I run Fedora 20 (3.13.10-200.fc20.i686) inside VirtualBox on a Windows 7 SP1 host. The Ethernet adapter on the guest is configured as a Bridged Adapter in VBox, and gets an IP via DHCP. Here's the ...
0
votes
0answers
29 views

How to use networks default gateway dynamically? [duplicate]

I want to use specific interface for specific use from different different application. I am using Ethernet, Wi-Fi and 3G modem interfaces in my embedded Linux set-up. Now my set-up is up with ...
4
votes
1answer
93 views

Linux routing for receiving packet

Maybe this is a dumb question. I have two NIC and they are in the same subnet. ip route commnad show above. Kernel was build WITHOUT policy routing. My question is: When receiving packet whether ...
2
votes
1answer
254 views

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 ...
0
votes
4answers
71 views

Linux routing tables

I'm trying to learn Linux routing tables and ran into bit of snag. In the example below I'm not sure what is happening. My understanding is 0.0.0.0 means that for line 1 and 2 any packets outside of ...
3
votes
1answer
134 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.
1
vote
1answer
42 views

How to use one nic for storage traffic & other for network traffic in Linux(Slackware)?

Problem I have a Linux machine (Slackware) with two network interface cards and i want to use one interface for network traffic and other for storage traffic . As this is Slackware i dont know this ...
0
votes
3answers
60 views

iptables rules - input and output

I'm new with Linux and iptables. I have a Ubuntu Server distro (12.04) on a PC which has 2 network interfaces (eth0 and eth1). I also have 2 laptops, one is plugged to eth0 and the other to eth1. ...
0
votes
1answer
58 views

Testing a Linux router on Laptop with one NIC [closed]

So, I have these instructions on converting my Linux machine to a router using (enable IP forwarding, NAT). Now my laptop has only one NIC and I want to test this setup. Any ideas how I can do this? ...
3
votes
1answer
64 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 ...
0
votes
1answer
69 views

DNS not resolving using IP rule for dialup modem

I am running Ubuntu 12.04. I have a HSDPA USB Modem, with which I can successfully dial in. It works fine as well when I set the default gateway (remote IP address) in the main routing table. But I ...
0
votes
0answers
132 views

On ssh connection the auth.log shows as source IP the external IP of the server instead of the IP of the client

I have a very odd situation with my ssh connection. Every time I connect to my server, whatever is my external ip, the connection have as source the server's external ip. Example Server S.O.: ...
1
vote
1answer
109 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 ...
0
votes
0answers
25 views

Routing Application through different network interfaces [duplicate]

I have two interfaces on a server, let's call them eth0 and eth1. The underlying server is running CentOS 6.5 I would like to be able for some application to use eht0 while some others use eth1. ...
1
vote
0answers
274 views

Understand the Route table

I just setup the OpenVPN and it is working as expected. However, the routing table of the client is confusing me to no end. Here is the route table: # route -n Kernel IP routing table Destination ...
1
vote
0answers
35 views

Different routing for each address on an interface

I know I can add several IP addresses to an interface without using interface aliases (ex.: eth0:0). My question: but how can I create different routing decisions for the different IP addresses on ...
1
vote
0answers
59 views

Linux Source Routing with one gateway

I've a Linux box which have IP 10.1.1.100/24 on eth0 with gateway 10.1.1.1 and as well as 20.1.1.1 on eth0:1 and 20.1.1.2 on eth0:2 . Is there any way that I could communicate to a remote machine ...
1
vote
0answers
35 views

invisible bridged router with 2 route table

my setup I have 2 ISP connexion : ADSL and SDSL. A qos (named qos, ip : 192.9.201.252) server stands before the ADSL router. It is the only way to access the ADSL gateway (192.9.201.254) through a ...
4
votes
1answer
326 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 ...
0
votes
1answer
47 views

Ip connectivity with two interfcaes

I have two network interfaces in Linux machine , eth0 and eth1. IP is assigned to both interface from two different VLANs and default gateway to eth0. Now if interface eth0 is down I am unable to ...
1
vote
0answers
111 views

SSH to a machine that is getting it's network connection from an Android device(Google TV)

I have a Linux(Ubuntu) machine for my HTPC. It's running XBMC and I control it via my IR remote control. I don't have a (wired) keyboard to control it. It has Wifi adaptor but it's not installed. I ...
6
votes
3answers
4k views

what is the meaning of 0.0.0.0 as a gateway?

Can anyone clarify gateway assignment for me? What is the difference between adding gateway as 0.0.0.0 and assigning a specific ip address as a gateway?
4
votes
1answer
256 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 ...
2
votes
0answers
200 views

SNAT problem in iptables

I am trying to reroute traffic from specific devices in my house over openvpn. For this, I've created an OpenVPN tunnel between my house wifi router and my server. Here is my setup: Wifi router's ...
2
votes
0answers
497 views

Adding multiple gateways for separate physical interfaces with various metrics/priorities

My system has 3 interfaces. These are eth0, eth1 and usb0. eth0 is linked to my router and is the line I want to be used by default. eth1 is un used. usb0 is a 3G phone that's tethered. My issue is ...
8
votes
1answer
1k views

Linux as router with multiple internet providers

Linux as router: I have 3 Internet providers, each with its own modem. Provider1, which is gateway address 192.168.1.1 Connected to linux router eth1/192.168.1.2 Provider2, gateway address ...
1
vote
2answers
241 views

iptables: what the difference between filter and mangle

I am using iptables to to mark the package and want to route based on the marks. First I added the ip rule: sudo ip rule add fwmark 1 prohibit (The "prohibit" is just for test, I will change it ...
1
vote
1answer
105 views

Routing 4 Networks

I've been trying for almost a week to make it work but without success. I'm starting to feel hopeless. I have 4 Ethernet adapters : 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state ...
1
vote
2answers
138 views

Using a specifing gateway for a packet. (CentOS/RHEL)

I have just setup a machine which has two NICs, one for private network and the other one for public network which has a real IP assigned to it. DEVICE=eth0 HWADDR=XXX TYPE=Ethernet UUID=XXX ...
1
vote
1answer
524 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 ...
1
vote
2answers
141 views

2 ip ranges / 1 nic OR why does one ip range follow default route before local routes

Updated at the bottom I'm using Centos as a router, and just replaced the routing system at work. I've got 2 routers to send data around. For the most part it's working. On one router I have 2 ...
2
votes
1answer
186 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
votes
1answer
140 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 ...
1
vote
1answer
1k views

Redirect Packets from ppp0 interface to ethernet interface in linux

My question is similar to this question, however with some change. I have a PPPoE connection on my Linux Machine (CentOS kernal 2.6.32) as a client, so that when I setup this connection, another ...
8
votes
1answer
1k views

Change remote host IP address without losing control (Linux)

How can I change a remote host primary IP address without getting disconnected at all (without being in a "no IP addr" state). The matter is poorly discussed on Internet (according to my research). ...
5
votes
4answers
15k views

How to remove all default gateways

I'm running a custom built linux machine, so not all linux commands are available. I execute network related commands, so I need to set a default gateway right before I run my command, then remove ...
5
votes
2answers
1k views

Network interface preference

How does Linux determine which network interface to use, when both are connected to the same network? Note that this isn't a question on routing. I'm familiar with how that works. This is if, say, I ...
6
votes
2answers
1k views

1:1 NAT with several identical LANs

I want to connect several LANs located on remote buildings. The "central" site have a Linux computer running OpenVPN. Each remote site also run OpenVPN. the central site has a LAN numbered ...
1
vote
1answer
300 views

Firewall/routing rule in Centos for this setup

I have two ethernet interfaces, namely eth0 and eth1. I want to implement an advanced routing rule but I am totally new to firewall/routing rules in CentOS. Here is what I am trying to do: Both my ...
4
votes
1answer
307 views

Using source routing (LSRR) - any ideas?

What I want to do is conceptually very simple, but I can't find any information or help about how to go about doing this. Basically, I want to configure my networking to use source routing (LSRR). ...
3
votes
2answers
414 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. ...
1
vote
1answer
2k views

iptables forwarding and routing

In fact, this question is about openwrt and CoovaAP, but I guess it's the same in other linux distributions. I've two interfaces, a "wan" and a "wlan" interface. Is there by default any filter, ...
2
votes
2answers
3k views

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 ...