Have you tried switching to 802.1q. It seems that if the problem is related to ISL then switching trunking protocols "might" help alleviate the problem. FWIW - Cisco is not supporting ISL on 2948 and 4000 switches, they're going to 802.1q only. Are they going to 802.1q everywhere? Your guess is as good as mine. -TY -----Original Message----- From: Jeff Wheat [mailto:jeff@cetlink.net] Sent: Tuesday, June 13, 2000 11:58 AM To: Neil J. McRae; Jason Slagle Cc: nanog@merit.edu Subject: RE: Broken 3640? We have an almost identical problem. I have a 3640 connected to a catalyst 2924XL. I have the switch and router both locked at 100/fdx. The crc error counters increment on the switch. According to cisco, this is related to bug id CSCdm49462. In short, when using ISL, the keeplives are not encap'd so the switch sees this as a crc error. The workaround is to disable keepalives on the router for that interface. Well we have tried this and this does not make a difference at all. We are still having lockups and continous crc errors. Bug id CSCdm49462 is a duplicate of CSCdm31600, which has been closed as there is a workaround (disable keepalives). If anyone can offer anything else on this I would very much appreciate it. (We have done the obvious and replaced cables and interfaces.) 2924XL: FastEthernet0/1 is up, line protocol is up Hardware is Fast Ethernet, address is 0001.4257.e241 (bia 0001.4257.e241) Description: ISL Trunk Feed to RHSC Core FastEthernet2/0 MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, reliability 255/255, txload 26/255, rxload 9/255 Encapsulation ARPA, loopback not set Keepalive not set Full-duplex, 100Mb/s, 100BaseTX/FX ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:00:58, output 00:00:00, output hang never Last clearing of "show interface" counters 21:28:28 Queueing strategy: fifo Output queue 0/40, 0 drops; input queue 0/75, 0 drops 5 minute input rate 3788000 bits/sec, 2043 packets/sec 5 minute output rate 10293000 bits/sec, 2302 packets/sec 144755645 packets input, 235743734 bytes Received 154190 broadcasts, 0 runts, 0 giants, 0 throttles 89993 input errors, 89993 CRC, 0 frame, 0 overrun, 585 ignored 0 watchdog, 60165 multicast 0 input packets with dribble condition detected 153666041 packets output, 3705280485 bytes, 0 underruns 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 3640: FastEthernet2/0 is up, line protocol is up Hardware is AmdFE, address is 00e0.1edf.8ba0 (bia 00e0.1edf.8ba0) Description: RockHill Main and Colo Lans MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, reliability 255/255, txload 10/255, rxload 26/255 Encapsulation ARPA, loopback not set Keepalive not set Full-duplex, 100Mb/s, 100BaseTX/FX 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 1w2d Queueing strategy: fifo Output queue 0/40, 33091 drops; input queue 0/75, 370786 drops 5 minute input rate 10277000 bits/sec, 2335 packets/sec 5 minute output rate 4235000 bits/sec, 2078 packets/sec 1450782711 packets input, 3672702950 bytes Received 6487551 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog, 0 multicast 0 input packets with dribble condition detected 1373258222 packets output, 2317298953 bytes, 0 underruns 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 Regards, Jeff

Lock the ports on the switch to 100FD, try a different switch...

...

Heres a followup.

This is a show int on the interface.

FastEthernet2/0 is up, line protocol is up Hardware is AmdFE, address is 0050.547b.e8c0 (bia 0050.547b.e8c0)