Hi All,
lately strange problem occures, i was unable to access (no telnet, no
ping) one of our routers that have been running for about 2 years now
without problems. After rebooting both router & connected Switch the
problem is solved, but after that i have found that pinging the router
from lan pc drop around 2% of the packets while invistigating the
problem i have found that the reliablilty of the ethernet interface is
varing from 195/255 to 238/255 !!. I tried to change both the ethernet
cable & the connected switch but the same results.

Any Idea.

here is some informations :

Router#sh int eth 0/0
Ethernet0/0 is up, line protocol is up
Hardware is AmdP2, address is 0007.85b1.efe0 (bia 0007.85b1.efe0)
Internet address is a.b.c.d/x
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
reliability 234/255, txload 11/255, rxload 11/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
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 01:47:42
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
5 minute input rate 466000 bits/sec, 521 packets/sec
5 minute output rate 449000 bits/sec, 131 packets/sec
3064844 packets input, 322288260 bytes, 0 no buffer
Received 19406 broadcasts, 0 runts, 0 giants, 0 throttles
323513 input errors, 0 CRC, 0 frame, 0 overrun, 323512 ignored
0 input packets with dribble condition detected
1098027 packets output, 489124696 bytes, 0
underruns(20169/57317/0)
0 output errors, 77486 collisions, 0 interface resets
0 babbles, 0 late collision, 32229 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out

Router#sh ver
Cisco Internetwork Operating System Software
IOS (tm) C2600 Software (C2600-I-M), Version 12.2(2)T1, RELEASE
SOFTWARE (fc2)
TAC Support: http://www.cisco.com/tac
Copyright (c) 1986-2001 by cisco Systems, Inc.
Compiled Wed 18-Jul-01 03:47 by ccai
Image text-base: 0x80008088, data-base: 0x809D68E8

ROM: System Bootstrap, Version 11.3(2)XA4, RELEASE SOFTWARE (fc1)

Router uptime is 2 hours, 2 minutes
System returned to ROM by power-on
System image file is "flash:c2600-i-mz.122-2.T1"

cisco 2610 (MPC860) processor (revision 0x203) with 28672K/4096K bytes
of memory
..
Processor board ID JAD05400A2X (221771976)
M860 processor: part number 0, mask 49
Bridging software.
X.25 software, Version 3.0.0.
1 Ethernet/IEEE 802.3 interface(s)
4 Serial(sync/async) network interface(s)
32K bytes of non-volatile configuration memory.
8192K bytes of processor board System flash (Read/Write)

Configuration register is 0x2102

Hi,
you have roundabout 7% collissions which is pretty high, I think.
I suggust the appropriate switch interface is running in full-duplex mode causing a duplex mismatch. This would be a typical reason for your described behaviour.
cheers
Horst

Thanks Horst for the reply

I tried changing from half to full duplex but no luck. and here is
another 2610 router connected to the same switch with even more
collissions but 255/255 reliability, I have a bad feeling that this
router is dying.

Router17>sh int eth 0/0
Ethernet0/0 is up, line protocol is up
Hardware is AmdP2, address is 0002.163c.7ea0 (bia 0002.163c.7ea0)
Internet address is q.w.e.r/x
MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
reliability 255/255, txload 36/255, rxload 22/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
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 02:49:04
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 0 drops
5 minute input rate 889000 bits/sec, 343 packets/sec
5 minute output rate 1424000 bits/sec, 365 packets/sec
3411352 packets input, 1201522959 bytes, 0 no buffer
Received 35681 broadcasts, 0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 input packets with dribble condition detected
3465994 packets output, 1827465139 bytes, 0
underruns(153225/361246/0)
0 output errors, 514471 collisions, 0 interface resets
0 babbles, 0 late collision, 211997 deferred
0 lost carrier, 0 no carrier
0 output buffer failures, 0 output buffers swapped out

Oh sorry,
that was a misunderstanding. Maybe I used the wrong english expression. I wanted you to change the switch to half-duplex because I supposed that the switch was running full-duplex and the router half-duplex. That would have been a good reason for such an behaviour.
Changing the switch to full-duplex is just the opposit of that what I wanted!
I've no Idea what else than a duplex mismatch can cause such a high percentage of collissions.
You are right, the second interface is even worse with 514471 collisions / 3465994 packets output. The average packetsize is roundabut 500Byte, which is o.k.
So my guess is still a duplex mismatch but you have to change the switch to half-duplex because these router interfaces look like they can only run half-duplex.
cheers Horst

Many Thanks Horst, you are sure right it's duplex missmatch, i changed
both the router and the switch to full-duplex and every thing is
running fine now zero collision & 255/255 rely. what i can't understand
is how was it running for the past 2 years !!!.
Thanks Again for the usefull help Horst.