Trigger packet drop on WS-C4948

[rprasant82]

Hi all

I am running  (cat4500-ENTSERVICES-M), Version 12.2(53)SG2 on the switch.

I have a scenario where I have 3 end user equipments connected to a cisco 4948 L3 switch.

At the switch end port 1/46, 1/47, 1/48 are the terminating points for these 3 devices . I have added these three ports to VLAN140 (switchport access vlan140 on the gig interfaces).

The device connected to 1/46 is the one Im testing some signalling features on. My requirement is to have intermittent packet drop on this interface so that my signalling associations would go down now and then. Im trying to simulate a real-time network congestion/latency/packet drop in a simple manner.

I do not want to shut/noshut the 1/46 intf to cause this.

Can experts point me to some way to acheive intermittent packet drop on this gig1/46 intf ?

[Wilson Bonilla]

Hello Prashant.

It would be difficult to trigger output drops under normal conditions, I would suggest te following step:

1- Enable qos on the switch.

2- Make sure all traffic coming from that interface is only handled by one specific queue.

3- Lower the bandwidth, buffers ... thresholds resources as much as possible for the queue in use.

That will definitely cause packet loss, now pay attention: the fact that you have to enable qos globally will change modify how the switch handles packet overall. you need to very very careful cause you can cause packet loss in other interfaces accidentally.

I hope this helps.

Regards

Wilson B.

[rprasant82]

Wilson

Thanks for the reply. I am using a dedicated switch for this scenario so I would not be bothered about packet loss pon other interfaces.

Shall try qos config on the switch. Can you share any specific doc/config that I can use ?

Thanks

Prashant R

[Wilson Bonilla]

Hello:

Enable qos

Configure terminal

qos

and then modify the interfaces tx-queues,

** Set the bandwidth queues values to accordingly to the amount of traffic you can generate to trigger output drops.

This link contains configuration examples:

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps4324/prod_white_paper0900aecd8041691c.html

Regards.

Wilson