Bug ID 448556: Wrong PPP MTU sent to a windows client after change in interface MTU

Last Modified: Apr 10, 2019

Bug Tracker

Affected Product:  See more info
BIG-IP APM(all modules)

Known Affected Versions:
11.3.0, 11.4.0, 11.6.0, 11.6.0 HF1, 11.6.0 HF2, 11.6.0 HF3, 11.6.0 HF4, 11.6.0 HF5, 11.6.0 HF6, 11.6.0 HF7, 11.6.0 HF8, 11.6.1, 11.6.1 HF1, 11.6.1 HF2, 11.6.2, 11.6.2 HF1, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 12.0.0, 12.0.0 HF1, 12.0.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1

Opened: Feb 11, 2014
Severity: 3-Major

Symptoms

An issue where Wrong PPP MTU sent to a windows client after change in interface MTU has been observed.

Impact

1) On BIG-IP set MTU on default interface to 1500 2) Connect to APM using windows client run "netsh interface ipv4 show interface" to check MTU on virtual PP interface 3) On BIG-IP Set MTU on default interface to 1200 4) Connect using a windows client run "netsh interface ipv4 show interface" to check MTU on virtual PP interface disconnect, try to connect to VPN again repeat (4) Randomly get one of two different MTU values on a client.

Conditions

Connect to APM using different APM sessions/connections gives different MTU values on a client PPP connection, depending on which tmm DTLS connection land.

Workaround

None. This is an intermittent issue and re-establishing the connection will likely set the correct MTU.

Fix Information

None

Behavior Change