I've seen a lot of info about running redundant routes to different ISPs
in the HOWTO and on this list. That surprises me, because I would expect
that a more common situation would be redundant routes to the *same* ISP
-- the typical HSRP + load balancing that so many of them run. Here's
what I want to do:
============ ============
ISP Router 1 ---- HSRP ---- ISP Router 2
============ \ / ============
| \ / |
| / \ |
| / \ |
============ / \ ============
My Router 1 -- heartbeat -- My Router 2
(Linux) (Linux)
============ ============
| |
| |
============ ============
fw 1 fw 2
I'm thinking of running ECMP outgoing from the routers labeled "My
Router x" to the ISP routers. It's also probable that we'll have the
ISP's routers sending us alternating (ECMP) packets on the incoming
side. Our routers would have heartbeat running so that a failure on
either box would cause the surviving router to take over its IP and MAC
(VRRP is not a possibility for reasons not worth mentioning).
Two questions here:
- In some docs, I see mention of using SNAT on outgoing packets to keep
a connection hooked up with one router. That's only necessary for
multiple ISPs, right?
- Is this going to be more trouble than it's worth -- packet re-ordering
or some other unforeseen problems?
_______________________________________________
LARTC mailing list / LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
