Bug in Zebra KeepAlive timer

[Steve Scheck]

Hello,

I believe there is a bug in Zebra's BGP KeepAlive timer handling. Over
time, it appears to decay, such that the interval between Zebra's
tranmission of KeepAlive messages slowly but steadily grows until the
remote peer's Hold Timer expires and it closes the connection. This
typically takes 20-25 hours. Note that when this behavior is observed,
Zebra is configured not to generate any Update messages, which probably
explains why this bug has not been noticed before.

The behavior is consistent - when peering with Zebra, the session will
always die after 20-25 hours (usually occuring around 23-24 hours). I am
using an internal BGP implementation which has been designed for 
testing. It has maintained a stable session with a Cisco router for a
week, so I am certain the problem lies with Zebra and not in our
implementation.

Just wanted to bring this to your attention.

-sjs