Exchange Server Duplicate Messages - Cisco Caveat?

[ccaron]

I know that there was a problem with Cisco PIX and duplicate e-mail messages being received on an Exchange server.

There was a Cisco Caveat article, does anyone know what it is?

I know that the fix for the caveat was to simply upgrade the IOS to 6.2(3).

If anyone knows, I would greatly appreciate a reply.

Thanks!

[mostiguy]

Have you disabled smtp fixup?

no fixup protocol smtp 25

It doesn't play nice with MS's ESMTP implementation. I had similar behaviour to you with exchange 5.5 and it enabled

[ccaron]

No, I didn't. In fact, someone at Cisco gave me a Caveat Article that addressed this exact behavior and recommended upgrading the IOS.

After upgrading the IOS to version 6.2(3), the problem has not resurfaced.

I am looking for the article as a colleague has asked for it.

Thanks!

[jdepies]

Its not a IOS bug, I have been running 6.1.2 for over 11/2 years and I have never had that problem. I have run both 5.5 and Exch 2000 behind this firewall.

I also have always had the MailGuard (fixup smtp) enabled, so its not the problem.

[ccaron]

A 'Cisco TAC' engineer identified the caveat...so I am not dreaming this up.

It doesn't happen to everyone.

...and I never said I was running 6.1.2 at the time either...so 6.1.2 probably doesn't have the problem...:^)

-Chris

[mhoda]

Chris,

There is no fixup for ESMTP on the PIX as of yet. So, if you have:

fixup protocol smtp 25

Then, only 7 SMTP commands ( HELO, MAIL, RCPT, DATA, RSET, NOOP, and QUIT) are allowed.

ESMTP requires more commands.

Thats why either of the two things have to happen:

-Turn off smtp executing the following command:

no fixup protocol smtp 25

-Or, disable ESMTP on the Exchage Server .

Please refer to the following link on how to turn off ESMTP functionality:

http://www.microsoft.com/exchange/en/55/help/default.asp?url=/exchange/en/55

/help/documents/server/xog05031.htm

So, if the problem doesn't appear with Exchange and the MailGuard on the PIX then Exchange must be using SMTP.

I hope this helps. Thanks,

Mynul