Re: Network failure detection on linux boxes

KingLoose wrote:
> Hello Piltrafilla,
>
>
> Tuesday, January 10, 2006, 6:04:43 AM, you wrote:
>
>
> >
>
>
> Hello,
>
>
> A customer of mine has a two linux-based PCs acting as firewalls for 
> perimeter protection. Those boxes are linked to two different routers of 
> two different ISPs with different public address ranges.
>
>
> Internal address range is RFC1918-based and firewalls is the place where 
> NAT is done to public address range depending on which outbound link is 
> chosen (routing decision). Basically default route is placed to first 
> ISP and some particular websites are statically routed through the 
> second ISP.
>
>
> It is not possible to perform any kind of dynamic routing with any of 
> those ISPs, is there any kind of daemon of script that could run on the 
> fw boxes so that I could ping or access some hosts or websites on the 
> Internet through the first ISP and in case they are not accessible (any 
> kind of network failure, not only link fail on the WAN side of the ISP 
> router but also some backbone link of ISP) then it could just change the 
> default route in the boxes to go through the second ISP. NAT would be 
> outbound-performed on interfaces to each ISP router.

> -- piltrafilla
>
>
>
> BGP and AS number is they way to go..
>
>
>  KingLoose                            mailto:kingloose@gmail.com

Check out http://lartc.org/ if you dont want to implement BGP and want 
to load balance multiple internet links.

--
Manish
http://www.tuxspace.com/