OT: difficulty with moving server

Steve Campbell campbell at cnpapers.com
Thu Apr 15 19:31:20 IST 2010

Problem solved. See my last post.

I was able to do DNS lookups. Telnet wouldn't allow me to go outside. 
Turns out, the return from servers being sent an SMTP connect was being 
routed to the old firewall due to ancient ARP tables. The switch wasn't 
supposed to be doing anything arp-wise, and the address for the switch 
didn't even belong to us anymore.

All the logs from the firewall indicated acceptance. Maillogs indicated 
timeouts. So I wasn't sure a connection was leaving the firewall or not. 
It was leaving, it just wasn't getting the return handshake.

Thanks for all the pointers and help. We've never, ever had to flush 
this switch before and I've been here for decades.


Landon Stewart wrote:
>     I dont want to sound obvious, but did you change the default gateway?
> And while on the server can you do nslookups using all the servers in 
> /etc/resolv.conf? 
> With mailscanner running - What happens if you telnet to localhost 25 
> /and/ <serversip> 25 while logged into the actual mailscanner server 
> itself?
> What does "lsof -Pni tcp:25" look like?  Anything interesting?
> And last but not least what do the logs say?  Anything useful?
> -- 
> Landon Stewart <LStewart at SUPERB.NET <mailto:LStewart at SUPERB.NET>>
> SuperbHosting.Net by Superb Internet Corp.
> Toll Free (US/Canada): 888-354-6128 x 4199
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