Solved: Telnet garbled on smtp port via ASA

a.whiting · ‎06-09-2010

Hi folks,

I am experiencing garbled telnet sessions on port 25 to ms-exchange servers on the other side of an ASA5520.

This is an MS "basic check" for inter-server email comms, but is proving problematic.

SMTP is permitted through the ASA.

Suggestions welcomed, please!

Regards,

Andy.

Federico Coto Fajardo · ‎06-09-2010

Hi Andy,

SMTP is open by an ACL?

Are you inspecting SMTP or ESMTP through? This traffic passes the inspection fine?

Federico.

Federico Coto Fajardo · ‎06-09-2010

Hi Andy,

SMTP is open by an ACL?

Are you inspecting SMTP or ESMTP through? This traffic passes the inspection fine?

Federico.

a.whiting · ‎06-09-2010

Federico,

Yes, there's an acl permitting smtp, and "inspect ESMTP" is in the config.

From other forums I gather that this might be the issue.

Regards,

Andy.

a.whiting · ‎06-09-2010

Folks,

I have "fixed" the issue by "no inspect ESMTP".

I'm about to check whether this is a known cisco issue.

Thanks, Federico.

Regards,

Andy.