Bug ID 535759: SMTP monitor might mark the server down even if the server answers the HELO message.

Last Modified: May 29, 2024

Affected Product(s):
BIG-IP LTM(all modules)

Known Affected Versions:
11.6.0, 12.0.0, 12.0.0 HF1, 12.1.0 HF1, 12.0.0 HF2, 12.1.0 HF2, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2

Fixed In:
12.1.0, 12.0.0 HF3, 11.6.1

Opened: Jul 28, 2015

Severity: 3-Major

Related Article: K99840695

Symptoms

The SMTP monitor marks a server down even when the server responds with a 250 message to the HELO command. Monitor debug output might show the following error messages: -- ERROR: failed to complete the transfer, error code: 28 error message: Time-out. -- ERROR: failed to complete the transfer, error code: 56 error message: Recv failure: Connection reset by peer.

Impact

The monitored server is marked down when it is not.

Conditions

This occurs under any of the following conditions: -- The monitored server does not close the TCP connection (does not send a FIN) after receiving a QUIT command from the client. -- The server does not include the word 'Bye' in the 221 message in response to the 'quit' sent by the BIG-IP system. -- The server issues a RST for any reason after the BIG-IP system has successfully received the 250 response to the HELO message.

Workaround

None.

Fix Information

SMTP monitor now considers the server up if it receives a successful response to the HELO command.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips