arp messages XXX is on but got reply.../multihoming problem

[Dan Nelson]

In the last episode (Jan 18), Jer said:
> 4.9-REL
> 
> sis0: inside network 192.168.XXX.XXX
> 
> xl0: connection to RR commercial via DHCP
> assigned ip  24.172.21.XXX gateway 24.172.21.219 nat'd
> 
> rl0: unused
> 
> What I want to do is plug in an RR home connection to the rl0 interface so 
> rl0 would then look like
> rl0: connection to RR home via DHCP
> It got assigned an IP of 66.57.248.XX gateway 66.57.248.1
> 
> When I do this I get 1000's of
> arp: 66.57.248.1 is on rl0 but got reply from 00:07:0d:aa:ec:54 on xl0
> 
> and the speed of the xl0 slows to a crawl until I unplug the rl0 NIC

Make sure your xl0 and rl0 nics are not plugged into the same switch or
hub.  If they aren't, and your setup currently looks like:

 ___________     24.172.21.219           24.172.21.XXX
(           )---[RR business DSL box]---[xl0]
( Internet  )
(___________)---[RR home DSL box]-------[rl0]
                 66.57.248.1             66.57.248.XX 

, then RR may have problems providing both business and home DSL to the
same location, since there's no way xl0 should be getting ARPs from
66.57.248.1.

-- 
	Dan Nelson
	dnelson at allantgroup.com