Iljitsch van Beijnum wrote:
It doesn't really require that. Redundancy requires that the routers at the ends of two links both be different. Having one router at one end and two at the other is a good compromise in many situations.
OK, now I'm sure you don't actually do any engineering. In 25+ years, I've not found that router failure was a major or even interesting problem. Link failures are probably 80%. Upstream failures are probably another 5%, about the same as staff fumblefingers, power failures, and customer misconfiguration that somehow affects routing -- like the idiots with the 5 character password last week that got rooted and swamped their link so badly that BGP dropped. I've lived through "inverse multiplexing", and BONDING, etc, etc.... Sure, I've had routers that had to be rebooted every week to overcome a slow memory leak. But you're not fixing that.... A redundant router should be where it would be doing some good -- on a diverse link to another upstream. -- William Allen Simpson Key fingerprint = 17 40 5E 67 15 6F 31 26 DD 0D B9 9B 6A 15 2C 32