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Community Member

router to Switch Trunk

Hi any help is much appreciated !

I have 2x Cisco 3725 routers running 802.1Q trunks to 2x 2950T switch with enhaced switch software.

The switches are trunked together to form one logical device.

The router trunks have hsrp groups configured on each subinterface

I have configured the Native Vlan's correctly on the routers and the switch ends of the trunks.

But I am getting rapidly increasing deferred counters on the switch ports that connect to the routers.

All interfaces are 100Mb full duplex !

I doubt that this is a cable or physical problem, as it is happening in 2 setups.

Any ideas, I'm guessing at a software bug !

Community Member

Re: router to Switch Trunk

this is from Cisco's website

The deferred counter counts the number of times the interface has tried to send a frame, but found the carrier busy at the first attempt (Carrier Sense). This does not constitute a problem, and is part of normal Ethernet operation.

Community Member

Re: router to Switch Trunk

Hi, if you are trunking with the rj45 ports from the 2950T, sure it is a bug of that IOS version (increase of deferred counters in a exccesive rate).IOS 12.1(13)EA. I solved this by making a downgrade to 12.1(11)EA...greetings.

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