North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Cisco etherchannel question
Thanks for all of you who responded with info about etherchannel information. The core appears to be algorithm used for packet distribution among interfaces (which I can't change on 5500): "The EBC performs an X-OR operation on the last two bits of the source MAC address and the destination MAC address. This operation yields one of four results: (0 0), (0 1), (1 0), or (1 1). Each of these values points to a link in the Fast EtherChannel bundle" Apparently I have bad combination of source mac addresses (I only have 7 main servers responsible for most traffic and only one destination) and solution in this case appears to be to manually change MAC addresses of some servers until I can acheive better load-balancing. On Wed, 20 Oct 2004, william(at)elan.net wrote: > Hi, > > I have etherchannel setup between cisco 7500 router and 5500 switch. > > For data going from 7500 router everything seems to be ok and data is > well split between four interfaces with about 1/4th sent to each one > (about 40% utilization each right now). > > But for data going from 5500 switch the split appears to be that one > interface has 100% utilization while another one is 20% and others are > less then 10%. So its not really splitting data on random basis to > each interface and uses other interfaces as overflow after the main > one. I don't like this as the one interface that is 100% full appears > to sometimes be dropping packets on either switch or cisco router side. > > I'm wondering what I can do to force 5500 to use etherchannel in similar > way cisco 7500 does? -- William Leibzon Elan Networks [email protected]
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