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CRC & INPUT Errors

Hello,

I have a Cisco 2500 Series router, and lately I've been getting a lot of CRC & Input errors on the ethernet interface, about 250/minute I tried switching the cable and a different port on the switch but no luck. What could cause this? Could a virus or a worm cause this?

Here is the output for Show Interface

Ethernet0/0 is up, line protocol is up Hardware is AmdP2, address is 0005.3281.da20 (bia 0005.3281.da20) Internet address is 10.3.0.1/16 MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec, reliability 255/255, txload 2/255, rxload 17/255 Encapsulation ARPA, loopback not set Keepalive not set ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:00:00, output 00:00:00, output hang never Last clearing of "show interface" counters 00:09:18 Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 2/75, 0 drops 5 minute input rate 679000 bits/sec, 243 packets/sec 5 minute output rate 112000 bits/sec, 159 packets/sec 127617 packets input, 48804757 bytes, 0 no buffer Received 683 broadcasts, 0 runts, 0 giants, 0 throttles 432 input errors, 432 CRC, 0 frame, 0 overrun, 0 ignored 0 input packets with dribble condition detected 72361 packets output, 6796201 bytes, 0 underruns(0/0/0) 0 output errors, 0 collisions, 0 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out Serial0/0 is up, line protocol is up Hardware is PowerQUICC Serial Internet address is 192.168.1.1/30 MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, reliability 255/255, txload 24/255, rxload 2/255 Encapsulation PPP, loopback not set Keepalive set (10 sec) LCP Open Open: IPCP, CDPCP Last input 00:00:01, output 00:00:00, output hang never Last clearing of "show interface" counters 00:09:21 Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops Queueing strategy: weighted fair Output queue: 0/1000/64/0 (size/max total/threshold/drops) Conversations 0/2/256 (active/max active/max total) Reserved Conversations 0/0 (allocated/max allocated) Available Bandwidth 1158 kilobits/sec 5 minute input rate 14000 bits/sec, 13 packets/sec 5 minute output rate 150000 bits/sec, 39 packets/sec 5772 packets input, 673165 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 20715 packets output, 9926159 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets 0 output buffer failures, 0 output buffers swapped out 0 carrier transitions DCD=up DSR=up DTR=up RTS=up CTS=up

Serial0/1 is up, line protocol is up Hardware is PowerQUICC Serial Internet address is 192.168.1.5/30 MTU 1500 bytes, BW 1544 Kbit, DLY 20000 usec, reliability 255/255, txload 44/255, rxload 5/255 Encapsulation PPP, loopback not set Keepalive set (10 sec) LCP Open Open: IPCP, CDPCP Last input 00:00:00, output 00:00:00, output hang never Last clearing of "show interface" counters 00:09:24 Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops Queueing strategy: weighted fair Output queue: 2/1000/64/0 (size/max total/threshold/drops) Conversations 1/4/256 (active/max active/max total) Reserved Conversations 0/0 (allocated/max allocated) Available Bandwidth 1158 kilobits/sec 5 minute input rate 33000 bits/sec, 36 packets/sec 5 minute output rate 270000 bits/sec, 78 packets/sec 13188 packets input, 1481393 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 36278 packets output, 16822755 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets 0 output buffer failures, 0 output buffers swapped out 0 carrier transitions DCD=up DSR=up DTR=up RTS=up CTS=up

Serial0/2 is up, line protocol is up Hardware is PQUICC with Fractional T1 CSU/DSU Internet address is 192.168.1.9/30 MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec, reliability 255/255, txload 31/255, rxload 2/255 Encapsulation PPP, loopback not set Keepalive set (10 sec) LCP Open Open: IPCP, CDPCP Last input 00:00:00, output 00:00:00, output hang never Last clearing of "show interface" counters 00:09:26 Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops Queueing strategy: weighted fair Output queue: 0/1000/64/0 (size/max total/threshold/drops) Conversations 0/2/256 (active/max active/max total) Reserved Conversations 0/0 (allocated/max allocated) Available Bandwidth 1152 kilobits/sec 5 minute input rate 14000 bits/sec, 16 packets/sec 5 minute output rate 183000 bits/sec, 34 packets/sec 15301 packets input, 1780811 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort 33218 packets output, 18992283 bytes, 0 underruns 0 output errors, 0 collisions, 0 interface resets 0 output buffer failures, 0 output buffers swapped out 0 carrier transitions DCD=up DSR=up DTR=up RTS=up CTS=up

This router also has 3 serial interfaces, and the remote locations that connect to this router have experienced very slow and dropped connections in the past couple of days and trying to reslove it but no luck and all the remote users are getting frastruted.

I've read another post where someone mentioned to download network analyzer to see whats causing these errors, so I'm dowloading the solarwind oreon network analyzer, does anyone know how to use it and what to look for?

Any help and advice is greatly appreciated, and thank you in advance.

Sincerely, Igor Pinchevskiy

Reply to
Igor Pinchevskiy
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In my experience, it means the interface on the other side of that link is running at Half Duplex and so is reporting back Collisions & Late Collisions on the link, which this interface reports as Input errors and CRC errors.

Reply to
Arthur Brain

Since this is an ehternet interface which connects to a local area switch with about 30 other devices, do you think this is caused by a single device, should I switch it back to half duplex?

Reply to
Igor Pinchevskiy

Hello Arthur,

I checked one of the remote router's ethernet interface and it wasn't set to full duplex, so i changed it and the CRC's went down, but still getting some, about 5 every 5 minutes or so.

Reply to
Igor Pinchevskiy

I was going to suggest doing a sh int on the other end of the ethernet link (you should have seen Collisions & Late Collisions, plus seen what it had for a Duplex configuration).

Setting Auto/Auto at each end might work, otherwise forcing both ends of the link as 100Mb/FullDuplex might be required.

For a comms link like this, specifying 100/FD on both ends would be the preferable planned configuration, I think.

Having said that, I had one recently where collisions and/or other errors were generated on a link with every single combination of speed/ duplex EXCEPT Auto/Auto, which was weird.

Reply to
Arthur Brain

make sure you stick to a standard configuration for NICs and switch ports. either have both side in auto-negotiate or hard-coded. there have been many times where i argued with the server deployment team to set their NICs to 100/full since i hard-code my switch ports to 100/ full.

collisions / align errors / runts are good indicators of duplex mismatches.

Reply to
brickwalls19

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