[c-nsp] Odd Etherchannel behavior between 7507 and cat 4006

[Lee]

My experience has been that setting the speed and duplex on a catalyst
switch stops it from doing auto-negotiation.  So with the switch ports
set to 100/full I'd expect the 7500 ports to come up as 100/half.  But
we don't have any cat4006s at work.. I don't know if they do
auto-negotiation even if the port speed and duplex is configured,

Lee


On 4/6/09, Bill Wichers <billw at waveform.net> wrote:
> I have a strange problem getting an Etherchannel link betweek a 7507 and
> a Cat 4006. Basically everything works, but the two FE interfaces on the
> 7507 (both in the same VIP) keep dropping their "full-duplex" config and
> reporting "unknown duplex" instead. Traffic works across the link, load
> is about the same on both member links, only the weird duplex problem -
> which is causing some errors to show on the port.
>
>
>
> Config on the switch is very simple:
>
>
>
> set port speed      2/1-2 100
>
> set port duplex     2/1-2 full
>
>
>
> set trunk 2/1  on dot1q 1-1005,1025-4094
>
> set trunk 2/2  on dot1q 1-1005,1025-4094
>
> set port channel 2/1-2 mode on
>
>
>
> Just two FE interfaces in the group.
>
>
>
> Config on the router isn't very complicated either:
>
>
>
> interface Port-channel1
>
>  no ip address
>
>  load-interval 30
>
>  hold-queue 150 in
>
> !
>
> interface FastEthernet1/0/0
>
>  description EC to core switch 2/1
>
>  no ip address
>
>  channel-group 1
>
> !
>
> interface FastEthernet1/1/0
>
>  description EC to core switch 2/2
>
>  no ip address
>
>  channel-group 1
>
> !
>
>
>
> There are a few virtual interfaces on the port-channel using 802.1q tags
> and they all seem to work, they're setup the usual way of "port-channel
> 1.123 / encap dot1q 123 ... etc.
>
>
>
> Router is running 12.2(6a), cat is running 8.4(8)GLX. There is no fancy
> L3 blade in the cat. It seems like the router is just loosing the
> 'full-duplex' part of the config of the two member links and aside from
> that everything seems to work. Any ideas?
>
>
>
>    -Bill
>
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