configure Linux so that if it can not access web pages over one nic to use other nic

[Brien Dieterle]

Jim B wrote:

> What is the best to have 2 internet connectinons to one linux box on 2
> different ethernet interfaces and if the web can not be accessed over
> one nic for Linux to then use the other nic for Internet access?
>  
> Basically nic A is for intrnal network and to access the Internet
> nic B is only to access the internet which should be used for Internet
> access as the primary.
>  
> Basically I would like to configure the Linux box to have redundant
> Internet access.
>  

You probably want to look at the "metric" option when setting your
routing table.  I believe you should have two "default" routes
(0.0.0.0), and the "backup" interface should have a higher metric value
than the normal interface.  It might look something like this, then
again it might not:

Destination     Gateway         Genmask         Flags    Metric   Ref   
Use  Iface
default         10.0.0.1        0.0.0.0           U        0      
0      0    eth0
default         192.168.0.1     0.0.0.0           U        1      
0      0    eth1

brien