Last Modified: Oct 16, 2023
Affected Product(s):
BIG-IP LTM
Known Affected Versions:
11.5.4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.5.10, 11.6.0, 11.6.1, 11.6.2, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3, 12.0.0, 12.0.0 HF1, 12.1.0 HF1, 12.0.0 HF2, 12.1.0 HF2, 12.0.0 HF3, 12.0.0 HF4, 12.1.1 HF1, 12.1.1 HF2, 12.1.2 HF1, 12.1.2 HF2, 12.1.0, 12.1.1, 12.1.2, 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, 12.1.5, 12.1.5.1, 12.1.5.2, 12.1.5.3, 12.1.6, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.2, 13.1.1.3, 14.0.0, 14.0.0.1, 14.0.0.2, 14.0.0.3, 14.0.0.4, 14.0.0.5, 14.0.1, 14.0.1.1
Fixed In:
14.1.0, 13.1.1.4
Opened: Jun 08, 2018 Severity: 3-Major
When newer link-state advertisement (LSA) (with greater seq) comes in, the Open Shortest Path First (OSPF) discards the old one by marking it DISCARD. The SPF calculation function suspends the calculation every 100 vertexes. If the discard happens during such a suspend, then after the calculation resumes, the discarded LSAs are ignored,n which can cause route unreachable, and eventually route withdraws.
Intermittent route flaps occur that might cause unreachable destination or increased network traffic due to the non-optimal route choice.
A very large number (~500, beyond best practices) of routers in a single OSPF area.
There is no workaround.
The 'vertex threshold' IMISH parameter is now provided for OSPF/OSPF6, and it is meant to control the amount of vertexes calculated in one bunch (the default value is 100). This value can be increased to prevent LSA discards.