Bug ID 431800: LTM may fail to forward IPv6 packets that are smaller than 64 bytes

Last Modified: Nov 07, 2022

Bug Tracker

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

Known Affected Versions:
11.3.0, 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, 11.5.10, 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

Opened: Sep 25, 2013
Severity: 3-Major

Symptoms

In rare circumstances where IPv6 payload is very small (less than 6 bytes), the total packet size (headers + payload) may be less than 64 bytes. To satisfy IEEE 802.3, these runt frames must be padded to a full 64 bytes. This results in a discrepancy between actual L2 payload size (wire size) and calculated L2 payload size (IPv6 header size + IPv6 payload size). This discrepancy causes LTM to drop the packet.

Impact

Failure to forward IPv6 packets.

Conditions

Leverage a protocol which sends small IPv6 packets. This excludes TCP, UDP and ICMP.

Workaround

None.

Fix Information

None

Behavior Change