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New Member

unknown protocol drops

Hi guys,

have you come across this error

unknown protocol drops which is seen under show int for either tunnel int ,gigabit ,serial or fastethernet.

Please let me know how do we overcome this error or is there any fix on this error.



New Member

Re: unknown protocol drops

The most likely cause of this would be packets/frames from protocols that the device doesn't understand or have enabled. 

Without troubleshooting I do not know of a way to be more specific.

Since you named every type of port possible it is hard to even identify the source of the errrors without troubleshooting so you will have to start somewhere and test everything. 

Step 1 will be to Identify the source .  Disconnect X and test.  X being your subnets.  You could probabally do some bulk tests for all WAN or all LAN before you start narrowing down the source subnet that the traffic is coming from. 

Also be minful of types of ports and what they have enabled.  If you enable a routing protocol on 1 switch/router and then connect it to another switch/router the 1st router/switch will be broadcasting the STP information to the other device and the other device will report unknown protocol drops.

Once you identify the source we can talk about how to resolve the error, but without a source the answer for ever possible problem will be way to long.