Inside to DMZ

[bigdog175]

I'm running a PIX 515 everythings is up and everyone is happy except for mail clients on the inside. I have a POP3 server on the DMZ and inside users use outlook when an inside user sends an e-mail with any attachment bigger than 1K outlook reports a SMTP error (unknown) sometimes a timeout waiting for SMTP to respond. Any suggestions are welcome thanks in advance.

 

[yizhar]

HI.

Is the mail server connected directly to the pix interface, or is there a switch/hub between them?
Try to configure the NICs of both the mail server and the pix (and the switch if needed) to 100full instead of Auto-Sensing.
Does this help?

The mail server might also be trying to use the obsolute IDENT protocol or to do reverse DNS lookup on incoming sessions, see these articles:

http://www.cisco.com/warp/public/110/21.html

http://www.cisco.com/warp/public/110/2.html

I guess this is the Ethernet speed issue.
The problems are with internal clients only because they come in a much higher speed (LAN), then sessions from/to remote hosts on the Internet (WAN).

Bye
Yizhar Hurwitz

http://come.to/yizhar

http://teachers.sivan.co.il/yizhar

 

[bigdog175]

The e-mail server is connected to a Cisco 2900 Switch which is connected to the PIX. I'll the NIC speed and duplex modes, and tehn look at the articles thanks.