Hi, Anybody with a lot of experience with Linux bonding setup in arp request mode?
We've used bonding in with active-backup and MII monitoring mode for a while, and it has worked when a switches died, but, we've now been caught a few times where a switch goes comatose, stop switching but keep the links up on all the ports (so MII monitoring does not detect the failure and does not fail over to the other slave). We've started looking at arp request mode and have done some tests. We're satisfied with how it solves the original problem (detect a comatose switch, and fail over to the other slave) but have a few questions: -What is a reasonable value for arp_interval? You obviously want a value small enough that the connection fails over before it affects applications, but not too small that it will flood the network. The documentation shows examples with a value of 60 ms, but googling, it seems that a lot of people use 200ms and even 500ms. How do you pick a value? Is there a science to it, or is it more of a guest work? -how do you administer the list of arp_ip_target? I am afraid that regardless of how we document it and how much we talk about it today, eventually, in a few years from now, the machines from the list will be decommissioned and nobody will remember to change the arp_ip_target on all the other machines in that subnet... -Should you put a machine's ip address be in its own arp_ip_target? When we did tests, we tried to do this, we actually tried to only put a machine in its list, it worked fine with arp_interval at 300ms, but the machine switched back and forth constantly between its two slave when we set arp_interval at 60ms. The reason we wanted to try was that somebody suggested to keep a list of all the machines on a given subnet, and to blindly use it for the arp_ip_target. -It seems that some routers do not reply to pings to themselves when they get busy (under heavy load). Does this happened with arp request? Will a router not answer an arp request if it's too busy, or are they supposed to answer all of them? The real question is, is it reasonable to only use the routers on the subnet in the arp_ip_target? Thanks. -- Yves. http://www.SollerS.ca/ http://blog.zioup.org/ _______________________________________________ Tech mailing list Tech@lists.lopsa.org https://lists.lopsa.org/cgi-bin/mailman/listinfo/tech This list provided by the League of Professional System Administrators http://lopsa.org/
