Hi Tom, Tom Matthews wrote: > One purpose of multiple default routes I believe is for use with IPMP failure > detection.
No. > When mpathd decides that it hasn't had an ICMP echo response from a default > router within the specified FAILURE_DETECTION_TIME (/etc/default/mpathd) it > attempts to failover within the multipathing group. When you setup IPMP and your test interface IP addresses are within the subnet where an defaultrouter is available the defaultrouter is used as the ipmp probe target. If there is no defaultrouter within the subnet of the test interfaces the probe targets are detected by sending out icmp requests to a multicast address. Systems answering are chosen to be the IPMP test partners. You are also able to configure manually test partners by adding host routes to them .. they have to be in the same ip subnet as the test interfaces. This is documented at http://docs.sun.com/ > Now if you have two (or more) default gateways defined then the loss of one > will not cause a multipathing failover as I understand it. If one defaultrouter goes away the other could still be probed, yes. But its the wrong approach to add an 'defaultrouter' to get more probe targets. Better deploy host routes. Multiple defaultrouters in the same subnet are not a good solution from my experience. > Multipath failure detection can/is also performed on a link basis (but you'll > want to ensure you're using autonegotiation on your NIC and switch for this > to be reliable). Autonegotiation is no requirement to make IPMP link failure detection work. It works also with forced link speeds. But we never recommend to use forced links. Its the biggest problem generator I have ever seen. There is a possibilty to avoid the probe based failure detection. But its not possible to switch off link based failure detection with the current IPMP implementation in opensolaris. regards Axel Klatt -- Axel Klatt [EMAIL PROTECTED] Sun Microsystems GmbH Sachsenfeld 4, D-20097 Hamburg Phone: +49-40-251523-415 Fax: +49-40-256811 SYSTEMS-TSC-NETWORK / EMEA --------------------------------------------------------- Sitz der Gesellschaft: Sun Microsystems GmbH Sonnenallee 1 D-85551Kirchheim-Heimstetten Amtsgericht Muenchen: HRB 161028 Geschaeftsfuehrer: Marcel Schneider, Wolfgang Engels, Dr. Roland Boemer Vorsitzender des Aufsichtsrates: Martin Haering _______________________________________________ networking-discuss mailing list [email protected]
