cisco

Sniffing traffic punted to CPU on Cisco 6500

Submitted by cliff on Wed, 21/03/2018 - 10:57

Sometimes your Cisco 6500 seems to having a hard time with high CPU. Most cases are pretty obvious, like rancid or librenms runs, arp or dhcpd storms. But sometimes it is not that obvious and you want to know which traffic flows to your CPU. Time to dump the packets to the CPU. The following has been retrieved from cisco.com.

Quick and Dirty Unsecure tunneling on IOS

Submitted by cliff on Mon, 12/03/2018 - 14:38

This is an old post, I posted here a couple of years ago for Arjen Halma. It was the first one I found, so i'm putting it back here for reference.

interface Tunnel0
 description tunnel to other side
 ip address <PTP-IP> <PTP-NETMASK>
 no ip redirects
 no ip unreachables
 no ip proxy-arp
 ip mtu 1480
 ip tcp adjust-mss 1420
 tunnel source Dialer0
 tunnel destination <TUNNELSERVER>
 tunnel mode ipip

Add additional routes for the network on the other sides ;)

 

Cisco QoS for SSH preference

Submitted by cliff on Fri, 28/04/2006 - 08:34

This post is a legacy post from my old weblog, it has been included as it seems to still have some hits. Old comments are included

Thanks to Saku Ytti, I have a little config snippet that will enable low delay QoS for Cisco 877W (with Advanced IP services) (Your mileage may vary on other Cisco's). It guarantees bandwidth on packets with a max of 200 bytes. This includes interactive SSH, icmp, VOIP and most games.

Cisco 877W Configuration

Submitted by cliff on Sat, 15/04/2006 - 08:17

This post is a legacy post from my old weblog, it has been included as it seems to still have some hits. Old comments are included

As promised in my last post I promised to put some configuration online for WIFI configuration on a 877W. But first, I experienced some problems getting VLANs working on the Ethernet ports. It seems you need an Advanced IP Services IOS for this and NOT the default Advanced Security Services IOS. Remember to get 12.4(4)T2 if you want ADSL2+ support!

The relevent WIFI config snippets:

Cisco / Foundry BGP Config to RPSL

Submitted by cliff on Fri, 17/09/2004 - 08:34

This post has been recoverd from the old site for archival purposes and as it has still been generating some hits.

Last year I built my self an Cisco/Foundry BGP config to RPSL generator to create RPSL for in an routing registry (I primarily use the RIPE database). I did this because there where only tools that could do the other way around, generate a config from your RPSL entries in the routing registry database. As I currently can't find any tool in the wild that can do this I'm hereby opening it to the world. 

Cisco IOS Password Recovery

Submitted by cliff on Fri, 19/03/2004 - 11:01

This post is a legacy post from my old weblog, it has been included as it seems to still have some hits. Old comments are included

This weblog was intended primarily to have an easy way to type my documents and to make them searchable commentable etc..

After looking at my webservers webstatistics, I saw some search requests for Cisco password recovery techniques. Well then let's explain it here for everyone to read: