throttles and overruns, why??

[hapklaar]

Hi, We're having problems with our Cisco 4500-M router, specifically it's fastethernet interface. With a show int fa 0 i get:
---cut---
Last clearing of "show interface" counters 09:36:42
Queueing strategy: fifo
Output queue 0/40, 0 drops; input queue 0/75, 177864 drops
5 minute input rate 1011000 bits/sec, 251 packets/sec
5 minute output rate 629000 bits/sec, 235 packets/sec
28908756 packets input, 2652872758 bytes
Received 79039 broadcasts, 0 runts, 0 giants, 2652 throttles
0 input errors, 0 CRC, 0 frame, 54687 overrun, 0 ignored
0 watchdog, 0 multicast
0 input packets with dribble condition detected
--- cut ---

As you can see the overruns and throttles are way too high and the input queue dropped a lot of packets. Does ne1 have a clue as to what might cause this?

PS the fastethernet interface never gets to handle more than about 40Mbit/sec

Thank you for your help!

Kind regards,
Erwin

 

[svermill]

Before I say anything, always remember to manually set your speed and duplex settings on all devices. Even Cisco recommends that you don't use their auto-negotiation "feature."

Now...

I can't remember what a "throttle" means. Someone posted that here or on another forum a few months back. You may find this a little helpful:

http://www.cisco.com/univercd/cc/td/doc/cisintwk/itg_v1/tr1904.htm

It's a basic ethernet troubleshooting guide. It addresses under-runs and over-runs, etc. Not throttles though.

Also, when was the last time you cleared those counters? They don't age out but accumulate until you 'clear counters.'

 

[CCIEWANNABE]

Throttles are an indication of an overloaded router. Route once; switch many

 

[CCIEWANNABE]

throttles indicate that the router is overloaded with traffic. The is the amount of times the receiver on the port has been disabled. Find the device MAC that is causing it use.

Check the output of the show interfaces switching command to see what kind of traffic that is overoading the port.
Use the show interfaces [ ] mac-accounting.
Once the source device's MAC address is found, the corresponding IP address can be found by checking the output of the show arp exec command.

There also could be a bug in the Cisco IOS Software version running. Route once; switch many

 

[hapklaar]

the router doesn't recognize the show interfaces switching command and show interfaces fastethernet 0 mac-accounting gives no output.. ?