Tom --

Replying to:

> Sounds like a stale ARP cache problem in the upstream router.
> I presume that "shorewall clear" doesn't improve the situation?

I didn't try "shorewall clear", but I'll try that tonight when I get
home and can do some more experimenting.

I =did= try an "arping -U" command to update the upstream router's
ARP cache, in case that might have been the problem.  FWIW, I haven't
run into stale ARP cache issues previously at my location; changing
the network card in my current firewall, at various times in the past,
never interrupted traffic.

I would also have thought (possibly naively?) that even if there had
been a stale ARP cache issue, it wouldn't have affected things if I
were originating connections from my firewall (as opposed to outside
hosts trying to connect to me).

Anyway, I'll try experimenting with this tonight.  I suppose I could
run "tcpdump" to see everything coming in from my Internet connection;
this should show me if replies are being sent to the wrong MAC address.
If all else fails, I could physically move the external network card
from my production firewall into the new firewall -- though, hopefully
understandably, I'd only want to do that as a last resort.

Do any other possibilities come to your mind, in case it turns out
not to be a question of a stale ARP cache?

Rich Wales      ===      Palo Alto, CA, USA      ===     [EMAIL PROTECTED]
http://www.richw.org   ===   http://en.wikipedia.org/wiki/User:Richwales

-------------------------------------------------------------------------
Take Surveys. Earn Cash. Influence the Future of IT
Join SourceForge.net's Techsay panel and you'll get the chance to share your
opinions on IT & business topics through brief surveys-and earn cash
http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV
_______________________________________________
Shorewall-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/shorewall-users

Reply via email to