[NTLUG:Discuss] OT: multiple routers question

[Darin W. Smith]

Speaking of routing, I have an issue, not Linux-specific.

At my workplace, we have a corporate account with an ISP that gives us 2 
static IP's.  They allow and expect us to have our own firewalls and 
routers behind those IPs.

Up until this week, we have been using only one of those IPs, going through 
an old SMC Barricade router.

Due to limitations with the number of Cisco VPN connections we can 
simultaneously make, we decided to use the second IP with another router, 
splitting off a few machines onto a different IP subnet.

So we now have:

                    DSL
                     |
                   switch
external IP1---------|-------------external IP2
   |                                   |
 SMC Barricade                       new router
  (10.10.11.2)                      (10.10.12.1)
   |                                   |
   |                                   |
   |----------------  -----------------|
                   |  |
                  switch
                     |
                   LAN

Everything works great, except that the new router (a DLink 604) 
periodically loses the ability to communicate to the outside 
world...however, we can ping and traceroute through it to hit external IP1 
on the barricade.  And when we do that, the whole outside world comes back.

Thinking we just got a defective DLink, I went out and picked up the 
cheapest Linksys (one of their "network anywhere" brands) router.

I set it up and it works great for about 45 minutes, then we lose the 
outside world again.  With the Linksys, while it can ping external IP2, 
that doesn't restore the connection to the outside world.  Only a reset of 
the router does that.  It's like the ISP's router just begins to deny 
traffic from it until we give it a reset.  We've tried a hub in place of 
the switch that takes the routers to the DSL modem, with the same effect.

No traffic seems to be affected going through the SMC Barricade.  I've 
noticed that the new routers (both cheapos) get very warm.  I'm theorizing 
that the little ARM processors in them are getting overheated.  I guess I 
can put a fan blowing over one to see if that helps.

Or, am I doing something totally wrong with the network architecture (and 
why would it affect only the new router)?  Or could there be a 
configuration issue on the ISP's router upstream of us?

D!

-- 
D!
Darin W. Smith
AIM: JediGrover