Bug ID 428467: max-concurrent-udp/max-concurrent-tcp maximum values

Last Modified: Apr 10, 2019

Bug Tracker

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

Known Affected Versions:
11.2.0, 11.5.0, 11.5.1, 11.5.1 HF1, 11.5.1 HF10, 11.5.1 HF11, 11.5.1 HF2, 11.5.1 HF3, 11.5.1 HF4, 11.5.1 HF5, 11.5.1 HF6, 11.5.1 HF7, 11.5.1 HF8, 11.5.1 HF9, 11.5.2, 11.5.2 HF1, 11.5.3, 11.5.3 HF1, 11.5.3 HF2, 11.5.4, 11.5.4 HF1, 11.5.4 HF2, 11.5.4 HF3, 11.5.4 HF4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 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

Opened: Aug 21, 2013
Severity: 2-Critical

Symptoms

If the max-concurrent-udp/max-concurrent-tcp dns cache parameters are set too high for the platform, the memory needed to fulfill the request may cause tmm to panic.

Impact

When this occurs, tmm can core.

Conditions

This occurs because tmm creates max-concurrent-tcp communication points, each of which has a 64 KB buffer. For example, 8 tmms at 64 KB each results in approximately 500 KB for a single communication point. When multiplied by 2 billion, there will be problems with memory allocation.

Workaround

None

Fix Information

None

Behavior Change