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discarded packets question

We have a Cat 3508 (8 Gig ports SX) connected to 5 Cat 2950-48 port switches via their respective Gig uplinks via SX GBIC's over 50-u multi-mode fiber. Via the Web interface of the 3508, port stat's show a large number of "Total Discarded Packets" (each port has about 200,000 packets discarded). When I perform a "show interface Gig 0/1" for one of the same interfaces, discarded packets are not there- you may have deferrals, input errors, collisions, and others, but no number that equals the discard value. Any ideas as to what would cause large numbers of discarded packets?

Cisco Employee

Re: discarded packets question

Does it match the number of transmit discards in following output or 'no dest' receive counters?

show controllers ethernet-controller gigabitEthernet 0/1

Is this a trunk port by any chance?

Community Member

Re: discarded packets question

Thanks for your reply. It is not a trunk port, pure switch to switch port with one VLAN. My customer is going to try the "show cont eth-cont" command and get that output to me. I'd forgotten that command, its quite a bit of data for transmit vs. recv.


Community Member

Re: discarded packets question

After clearing the counters on the Cat 3508 earlier this morning, we've accumulated about 600 Total Discards as viewed from the Web interface. Upon executing the "show controller eth-cont gig 0/1" we noticed that we have about 400 no dest rev unicast and about 200 no dest recv multicast. Am I to assume that these are the incoming packets being dropped from my closet 2950 switch uplinks, as this switch sort of serves as a distribution switch for the building? Is this sort of like an ICMP destination unreachable or similar?

Thanks in advance for any help.

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