August 26, 2009

Cisco IOS hidden tools

Hello there,

Just a quick overview over a couple of cisco hidden command useful in certain circumstances

1. ttcp

ttcp is only available on routers/layer 3 switches (of course ;-) )

For those familiar with iperf, ttcp is a kinda”ish” iperf

Start ttcp on one router in point 2 point scenario and ttcp on the other endpoint. One router will be in receiving mode, while the other will be in sending mode… running the command is quite straight forward, thus I will not demonstrate it here.

2. test crash

Ok this used to be hidden, but isn’t in newer IOS version. Test crash allows to simulate a crash.. so you came to the office one morning and found your switch dead… not log, not knowing what happened. test crash can help you dig into the problem by simulating the crash

**3. **test transmit

This is a very cool feature :-D (ah I love cisco :) ). You can simulate traffic to interfaces, using specific encapsulations and protocols…

4. ip route profile and show ip route profile

Used in conjonction, this “debug” command enables you to see route fluctuation.

5. csim start “number”

This emulates a voice call to the specified number… practical for VoIP testing environment.

6. show controller switch

Need to get a quick overview on your switch traffic stats. Suspect a congestion network? show controller switch will give you the quick heads up on where you stand

7. debug ip osfp monitor

This command enables you to monitor the OSPF SPF process

8. ip-con 2 con

Available on cisco 7500… it enables you to enter the VIP console to execute VIP commands on VIP boards

9.  ip osfp interface retry

Back to OSPF :) (the coolest routing protocol), by default OSPF pools retry on the interface 10 times… having too much fluctuation of states on the interface of your router? increase the pooling period.

10. show region

Displays how the memory is partitioned on the device

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