On Sun, Mar 27, 2016 at 08:55:36PM -0400, Hristo Asenov wrote: > Hello Quagga Community, > > A couple of months ago I needed to perform a test with ospf6d, where a router > is connected to a host through two redundant router links. I simulated a > router failure at the best path and waited how long it takes for the OSPF6 > protocol to detect the failure and switch over packet forwarding to the > second path. The version of Zebra and OSPF6 we used is 0.99.17. We did not > change the hello interval (which by default is 10 seconds) and left the queue > hold-down timer in Zebra set to 500 msec. I calculated the time to switch > over packet forwarding in Linux Data Plane to be about 30 seconds. Could > anyone help me understand where the extra 20 seconds delay is coming from? > > I understand that there is some delay in SPF recalculation and installing new > route through Netlink into kernel, but don’t know if this latency is long > enough to justify the extra 20 seconds. I also performed the same test in > GNS3 on Cisco image, and the data plane switchover delay there was about 7 > seconds. > > Greatly appreciate any help on insight on this issue,
The dead interval is 3 times the hello interval. After all a packet could be lost and you don't want the network to make drastic changes due to one dropped packet. -- Len Sorensen _______________________________________________ Quagga-users mailing list [email protected] https://lists.quagga.net/mailman/listinfo/quagga-users
