[kwlug-disc] Multiple gateways on one subnet

[unsolicited]

At what point does it make more sense to expend the effort on
re-subnetting the buildings rather than this? What are the
costs/benefits of either approach?

john at netdirect.ca wrote, On 05/26/2009 10:50 AM:
> kwlug-disc-bounces at kwlug.org wrote on 05/25/2009 06:45:13 PM:
>> Thanks. It's clearly going to take more work for me to understand
>> this, but it is a good document. Even knowing thet the proper term is
>> "multi-isp" is helpful. 
>>
>> Overall I think that IPCop is the wrong tool for this job. I think it
>> does not even have iproute2, which many tutorials (including the
>> Shorewall page) want me to use. In the interest of laziness and 
> impatience
>> I may chicken out and use DHCP reservations to solve the problem. 
> 
> I would think that one of the routing protocols might work. OSPF is what 
> I've used in cases like this in the past. Linux supports OSPF using the 
> Zebra package. It's not too hard to setup, like all things linux it takes 
> a few hours to understand but only results in a few lines of actual 
> changes.
> 
> You could also consider a manual approach. Choose a point to ping from 
> each router. It could be the ISP's router or a common point like Google or 
> OpenDNS. When a ping fails replace the default gateway with the remote 
> IPCop's address. Sensing a recovery is a little tougher to do now that 
> your gateway has changed.
> 
> Iproute2 can help you with this and is likely available as an add-on to 
> IPCop.