Bug ID 706102: SMTP monitor does not handle all multi-line banner use cases

Last Modified: Sep 13, 2023

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

Known Affected Versions:
12.1.0, 12.1.1, 12.1.2, 12.1.3,,,,,,,, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0,,,,,,,,, 13.1.1,,, 14.0.0,,,,

Fixed In:
14.1.0,,, 12.1.4

Opened: Feb 09, 2018

Severity: 3-Major


An SMTP monitor does not handle all multi-line banner use cases, such as when the banner is physically split across two packets. This issue is due to attempting to parse the banner value from the first packet without a portion of the banner value that may arrive in a second packet.


The SMTP monitor sends an RST after the first packet, and marks the resource down.


An SMTP monitor is configured; and uses a multi-line banner; and the SMTP monitor banner is split across two physical packets.


Use an SMTP monitor with a single-line banner. Or, rather than using an SMTP monitor, instead use a TCP monitor with send/recv strings.

Fix Information

An SMTP monitor handles all use cases that include a multi-line banner.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips