ISP inbound failover without BGP

[streiner at cluebyfour.org (Justin M. Streiner)]

On Mon, 3 Mar 2014, Eric A Louie wrote:

> Are there any other solutions, short of using BGP multihoming and 
> having them try to get their own ASN and IPv4 /24 block?

For what it sounds like the customer wants to do, this really is the right 
solution.  Most everything else has some level of 'ugly hack' attached to 
it, that can cause reliability/reachability problems at inopportune times 
(as opposed to problems that happen at opportune times).

If the customer is just looking for failover capabilities, they can take 
default via BGP from both providers, prefer one over the other, and use 
some other bits to prefer one provider over for inbound connectivity. 
They would not need very beefy routers for this.

That will get you basic service redundancy.  Add a second router, and they 
can have some protection in the event of a router failure.

It all really boils down to what the customer wants and is willing to pay 
for.  If they have services that need to be reliably reachable, then using 
a time-tested design is a prudent decision.

jms