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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: FEC (Fast Etherchannel) issues
> > This looks kinda like the right place for this issue, apologies if not: Cisco NSP or the like probably would have been more appropriate. > True or False? > > FEC (Fast EtherChannel) is not suibtable for router to router trunking > because of the way FEC load balances Depends. > I've heard and read in various places (although nothing conclusive) that > since FEC uses the last portion of a MAC address and hashs it to determine > which 100 meg link a packet goes. This is to prevent packets from > arriving on the other end out of order. Only brand 'C' switches do the MAC hash thing, the routers do things with "microflows" (unless per-packet stuff is enabled). > This would seem to suggest that FEC wouldn't work between routers or > similar layouts because there is only one MAC address on either end, > therefor packets would always go over the same link. Yes, between a given set of routers .. if you have brand 'C' switches in the middle. > Anybody have concrete details on this issue? Does FEC actually determine > load balancing this say? is ther another way to configure this? Don't put switches in the middle? -danny
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