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CRC and overrun counters increasing

Hi all,

I have a 3845 router connected to 1841 router through ethernet. both routers are connected through on board ports(G0/0 of 3845 to fa0/0 of 1841). In general both the ports are working fine. Due to some requiremet I want to increase the payload size. While i am testing the communication between these routers with payload more than 1500 bytes, CRC and Overrun erros are increasing at 3845 router interface. While for same payload there is no error recorded in 1841 router. Please help me to understand why this is occuring? what is the difference between 3845 and 1841 router, except speed, that the 3845 router is not able to process the packets from 1841 routers. speed and duplex setting is set to AUTO in bith the interfaces.

5 REPLIES
Hall of Fame Super Gold

CRC and overrun counters increasing

Are both router interfaces returning as Auto Full, Auto 100?  CRC would come up if they incorrectly negotiated to Auto-Half.

Re: CRC and overrun counters increasing

Hi leolaohoo, 

Both the interfaces are negotiating with 100 full. When I am trying to ping the 3845 router from 1841 router with payload upto 1506 byte it is working fine. However when I am exceeding beyond 1506 byte teh reliability also going down, CRC increasing, Giant and overrun increasing. Here with I have attached a o/p analysis file .

Thanks & regards,

Satya.

Hall of Fame Super Gold

CRC and overrun counters increasing

Both the interfaces are negotiating with 100 full.

Can you please post the output to the command "sh interface " of both routers please?

Re: CRC and overrun counters increasing

Hi,

Please find the same . I have attached the ping response from both routers to both routers as well as the show interface o/p after each ping taken parallel.

Hall of Fame Super Gold

Re: CRC and overrun counters increasing

     reliability 246/255, txload 1/255, rxload 1/255

reliability 244/255, txload 1/255, rxload 1/255


Gotcha!

Check your cable. 

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