On Sat, Jan 06, 2001 at 12:21:33PM -0500, Jeff Mcadams wrote: > Also sprach Mr. James W. Laferriere > > Hello Whomever , BGP has -NO- functionality -UNTIL- you have more > > than one provider . Is that part understandable ? > > What you say is understandable, but, unfortunately, wrong. > > Multiple connections to the same ISP can be arbitrated by BGP, if, for > no other reason, that BGP gives you a reliable way to tell if the next > hop router is alive (if it can talk BGP, it most likely can pass > packets). What the original question called for was doubly connected host to two switches and behind them to possibly several routers, all within same ISP. At my work we have multiple routers, and multiple switches running in failover mode. At switching level we have 802 Spanning Tree Protocol doing cable path failover, and at routers we have HSRP. Nobody has supplied (in Solaris) an internal virtual ethernet switch which could take part in spanning-tree enabling system to have a single "ether interface" which fails over with STP to working path. For machines which are wanted to be multiply connected, we run OSPF at those hosts to switch default-route to another cable if connecting cable, or switch fail. Over the years we have had switch and router hardware failures quite rarely - MTBF is in order of years anyway. Having lots of boxes does mean that failures tend to happen roughly monthly, but not at the same devices. What has happened a lot more often is cabling plant failures where some cable has been mispaced into e.g. some cabinet door hinge side, and got squized badly, or been pulled strongly enough to break connector. Most often these failures are intermittent, and damn difficult to find, e.g. one goes to the cabinet and opens to door, no problems... /Matti Aarnio - : send the line "unsubscribe linux-net" in the body of a message to majordomo@vger.kernel.org
