[nsp] another strange 2950 behavior
Valeriu VRACIU
vvraciu at iasi.roedu.net
Sun Jul 18 13:17:40 EDT 2004
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Hello,
We have some strange phenomena happening on a 2950. One of its FastEthernet
ports is connecting, via optical fiber and media converters, a distant
location. All worked fine for more than 1 year, until a couple of days ago
when, suddenly, the connection begun to work chaotically, very slow or even
not at all. Reloading local or remote switch helps sometimes.
The strangeness is the respective port showing more MAC addresses than there
are at the other end, created by replacing some of real addresses figures
usually with 5. Here is an output with 19 addresses (yesterday I've seen a
table with more than 200 false MAC addresses on the same interface !!), at
the distant location we have just 4 hosts and one 2950 switch.
sw-lan#sh mac-address-table interface fastEthernet 0/15
Mac Address Table
- -------------------------------------------
Vlan Mac Address Type Ports
- ---- ----------- -------- -----
98 0002.3fd1.1408 DYNAMIC Fa0/15
98 0002.3fd1.1450 DYNAMIC Fa0/15
98 0002.3fd1.14f0 DYNAMIC Fa0/15 < host
98 0002.3fd1.45f6 DYNAMIC Fa0/15
98 0002.3fd1.55f0 DYNAMIC Fa0/15
98 0002.3ff1.14f8 DYNAMIC Fa0/15
98 0002.5fe3.5e56 DYNAMIC Fa0/15
98 0008.219f.62c0 DYNAMIC Fa0/15 < remote switch
98 0008.219f.62c1 DYNAMIC Fa0/15 < probably also remote switch
98 0025.3fd1.c5f0 DYNAMIC Fa0/15
98 0050.048a.ea71 DYNAMIC Fa0/15 < host
98 0050.048a.ea74 DYNAMIC Fa0/15
98 0069.279f.62c1 DYNAMIC Fa0/15
98 0076.ce60.4000 DYNAMIC Fa0/15
98 0080.adb7.80fd DYNAMIC Fa0/15 < host
98 00b0.6409.ebc1 DYNAMIC Fa0/15 < host
98 505f.555d.5b04 DYNAMIC Fa0/15
98 525f.7555.5a55 DYNAMIC Fa0/15
98 8063.3d54.5d75 DYNAMIC Fa0/15
Total Mac Addresses for this criterion: 19
Also, there are many CRC errors on the local and remote switches' interfaces,
errors that I haven's seen before:
local switch:
sw-local#sh int fast 0/15
FastEthernet0/15 is up, line protocol is up (connected)
Hardware is Fast Ethernet, address is 000a.b7b0.f50f (bia 000a.b7b0.f50f)
MTU 1500 bytes, BW 100000 Kbit, DLY 1000 usec,
reliability 236/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s
input flow-control is off, output flow-control is off
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:01, output 00:00:02, output hang never
Last clearing of "show interface" counters 01:42:42
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 7000 bits/sec, 1 packets/sec
5 minute output rate 8000 bits/sec, 1 packets/sec
38553 packets input, 5990235 bytes, 0 no buffer
Received 2993 broadcasts (0 multicast)
0 runts, 0 giants, 0 throttles
3250 input errors, 2794 CRC, 436 frame, 0 overrun, 0 ignored
0 watchdog, 2918 multicast, 0 pause input
0 input packets with dribble condition detected
39362 packets output, 17656364 bytes, 0 underruns
73 output errors, 3 collisions, 2 interface resets
0 babbles, 73 late collision, 5 deferred
0 lost carrier, 0 no carrier, 0 PAUSE output
0 output buffer failures, 0 output buffers swapped out
remote switch:
sw-remote>sh int fast 0/1
FastEthernet0/1 is up, line protocol is up (connected)
Hardware is Fast Ethernet, address is 0008.219f.62c1 (bia 0008.219f.62c1)
MTU 1500 bytes, BW 100000 Kbit, DLY 1000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Full-duplex, 100Mb/s
input flow-control is off, output flow-control is off
ARP type: ARPA, ARP Timeout 04:00:00
Last input 00:00:15, output 00:00:01, output hang never
Last clearing of "show interface" counters 03:41:53
Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 8000 bits/sec, 2 packets/sec
5 minute output rate 6000 bits/sec, 4 packets/sec
177712 packets input, 45037887 bytes, 0 no buffer
Received 4771 broadcasts (0 multicast)
0 runts, 0 giants, 0 throttles
543 input errors, 463 CRC, 51 frame, 0 overrun, 222 ignored
0 watchdog, 2924 multicast, 0 pause input
0 input packets with dribble condition detected
184373 packets output, 20061876 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 PAUSE output
0 output buffer failures, 0 output buffers swapped out
Local switch is WS-C2950-24, remote is a WS-C2950-12, both are running the
same standard image c2950-i6q4l2-mz.121-19.EA1.bin. I have not attached the
configurations mainly because the message is allready too long. We tried
already to change the switches (tried a SMC switch at remote location),
media-converters, also patchcords (UTP and fiber), the behavior is same. If
someone has seen this before, please share some ideas, it's becoming
nightmare. Is it possible the problem is not related to the 2950s and we just
have problems with the physical layer (faulty optical cable or splicing
between the two locations) ?
Thank you for patience, sorry if I bothered the list members with this long
message, please be indulgent as this is my first post to this list -:)
Best wishes.
=================================
Valeriu VRACIU
Network Engineer at RoEduNet Iasi
tel: +40 (232) 201003
GSM: +40 (744) 615251
e-mail: vvraciu at iasi.roedu.net
=================================
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