Setting different metrics for different interfaces

mopoke · n00b Joined: 24 Jul 2005 Posts: 8

Hello,

I may be barking up the wrong tree here so I'll explain my situation first.

I have two network interfaces - eth0 (wired) and eth1 (wireless). I am normally wired but I am happy for the wireless to be on in the meantime (which is what I normally do). Therefore I have net.eth0 and net.eth1 in my default rc profile.

When I boot they both come up but I have no outbound connectivity. Looking at the routing table, this is because there are two default routes (one for each interface) and they have the same metric (0).
Output of route:

m_beli · n00b Joined: 11 Jun 2005 Posts: 8

Well, you cannot have two default routes at the same time (at least in your situation). As I understand, what you're trying to do is to be connected either through eth0 or eth1. Well then, you must tell your kernel which interface you want to use at the moment. It can be done manually, you stop one interface and start the other...
Or it can be done automatically, when you unplug the ethernet cable, the eth0 interface goes down and the route to eth1 is used. It can be done with ifplugd, there is a howto for ifplugd somewhere in the gentoo docs.