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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: MAE-east weirdness
> Did this happen on Friday? If so I heard from a directly knowledgeable > source that there was a power failure in Dallas that affected the MFS pop > there and that MFS had to bring in a truck with generators to get the > node operational again. If this is correct wold the looping be really > blamable to either UUNET or Sprint? > > ******************************************************************** > Gordon Cook, Editor & Publisher Subscript.: Individ-ascii $85 The trace shows bouncing between sites which are both local to Washington DC. I don't see how Dallas comes into this, unless at least one site involved is pointing default somewhere (which could cause this). My understanding is that both Sprint and Alternet run defaultless (as do many multihomed providers who have a reasonable route table such as MCS.) Discontinuities in a defaultless network do not show up as route loops -- they show up as !Hs or black-holes (ie: no returns at all) somewhere along the line, depending on ICMP configuration issues. You *can* get them if one or more of the routers in the game are pointing default (or have a less-specific CIDR route) in a way which can be looped back. This is an architectual problem which needs to be found and fixed -- looping packets will destroy the efficiency of your circuits (consider the TTL of most packets and the number of bounces before they TTL out). Hard-wired and "pulled-up" routes can also cause this kind of silliness. -- -- Karl Denninger ([email protected])| MCSNet - The Finest Internet Connectivity Modem: [+1 312 248-0900] | (shell, PPP, SLIP, leased) in Chicagoland Voice: [+1 312 248-8649] | 7 POPs online through Chicago, all 28.8 Fax: [+1 312 248-9865] | Email to "[email protected]" for more information ISDN: Surf at Smokin' Speed | WWW: http://www.mcs.net, gopher: gopher.mcs.net
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