Ping packet loss on ethernet interface

powys · ‎08-04-2006

Does anybody know why I am losing packets when pinging the router interface but when I ping a server on the LAN beyond the router interface I don't lose any packets? The router is a 3662 and doesn't look busy, all other interfaces are responding OK.

farkascsgy · ‎08-04-2006

Is there any ACL on this interface which deny echo reply packets?

What does it means not so busy?

bye

FCS

Please rate me if I helped.

jackyoung · ‎08-04-2006

Try to make a trace route and check the result. You can also try to ping from hosts to this router interface to compare the result.

Hope this helps.

powys · ‎08-07-2006

Trace route works ok. The hosts get the same poor ping response as myself. Other fast ethernet ports on the router are behaving fine including a port in teh same module.

powys · ‎08-07-2006

There is an ACL on this interface but it doesn't deny echo reply packets. I've removed the ACL and it makes no difference. The router's CPU utilisation normally runs at 1%. At it's busiest during weekend backups it runs at 15%.

abhayaa123 · ‎08-07-2006

1. Is the router in LAN or wan.

2. If wan how do u connect what is the connectivity .

3. Whether there are 2 links to the site and whether the traffic is getting load balanced betn two links.

4. Type of load balancing per-packet ot per destination.

jackyoung · ‎08-07-2006

Do you mean you ping from a LOCAL PC to the router Ethernet port w/o via any routing ?

If yes, I suspect it may be failure on this module / port. Because there is no problem on the same module but different port.

Can you provide the "show interface" of this interface ?

powys · ‎08-07-2006

If you ping from a local PC to the router (no routing it is the PC's gateway) you get a poor response.

I think the port may be faulty but I could try swapping this link into another port out of hours to check.

Please find enclosed show interface:

FastEthernet4/0 is up, line protocol is up

Hardware is AmdFE, address is 0001.4255.a241 (bia 0001.4255.a241)

Description: Fibre Link to Llandod HS

Internet address is 172.16.32.1/24

MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,

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

Encapsulation ARPA, loopback not set

Keepalive set (10 sec)

Full-duplex, 100Mb/s, 100BaseTX/FX

ARP type: ARPA, ARP Timeout 04:00:00

Last input 00:00:01, output 00:00:00, output hang never

Last clearing of "show interface" counters 3d02h

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 5000 bits/sec, 6 packets/sec

5 minute output rate 4000 bits/sec, 4 packets/sec

3958023 packets input, 2795845396 bytes

Received 251946 broadcasts, 0 runts, 0 giants, 0 throttles

0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored

0 watchdog

0 input packets with dribble condition detected

4285193 packets output, 3100303661 bytes, 3 underruns

3 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

ikizoo4 · ‎08-07-2006

Check the duplicate IP address..

b-ulrich · ‎08-07-2006

Hi, I have run across weirdness like this on 2651's. Try shut/no shutting the interface. This is what I do and the issue goes away. I believe what I usually run into is a bug in the IOS.

powys · ‎08-08-2006

Hi

Thanks - I've tried that and it's still having problems. I'm going to swap interfaces to see if the problem remains with the interface.