keepalived: adjusting timeout for VRRP advert packets

Question

I have a master server and a backup server that share a floating IP use keepalived for failover. I haven't explicitly defined any health checks, so I assume that the backup server grabs the floating IP and transitions to master status whenever it hasn't received any VRRP advert packets from the master service for some period of time.

We appear to have intermittent network connectivity issues between the two servers, so the backup often makes superfluous transitions to master. I would like to adjust the timeout for advert packets so the backup is less sensitive to network blips. From the documentation (http://www.keepalived.org/pdf/UserGuide.pdf), we have:

• advert_int, but that looks like it just changes the broadcast frequency, and
• delay_loop, which specifies "the interval between checks", but I'm not sure whether it applies to advert packets or just health checks.

Is what I'm trying to do possible? If so, which configuration option do I use?

Solution

You have to adjust "advert_int".

Transit from the MASTER to the BACKUP is triggered when the BACKUP server doesn't recieve the VRRP advertisment from the MASTER for 3x the period defined in the "advert_int" option (3 * advert_int).

Comments

[prolibertas]

Thank you! I found a reference. Check out the definition of Master_Down_Interval in the RFC