Host Mac Addresses on a Cisco Switch

I have to find where a server nic is connected in the network. I was certain there was a way to know what mac address was on which port but I needed Google to find a good article to show me how to get that information.

Once on the switch you can simply execute:

sh mac address-table

to see all the mac addresses the switch is aware of but when you are looking for a specific mac address you can execute this:

sh mac-address-table address 0011.bbcc.ddzz

Very simple and very convenient if I could only find the nic somewhere.

Ref.: http://www.itsyourip.com/cisco/howto-find-switchport-for-a-mac-address-on-a-cisco-catalyst-switch/

Cisco VPN Client and Linux Kernel 2.6.21

I had some problems installing the Cisco VPN client 4.8 on my Slackware 12.0 workstation so I searched a bit on the net and fond a page that had almost everything to the t: http://blog.360.yahoo.com/blog-.WURHFYwdq8.zfEosWC6j8jQ?p=55. A few very small differences that are due to the fact that the kernel has changed a bit more since this doc. So here are the very quick steps:

  1. cd /usr/src/linux/
  2. make menuconfig – and check that everything is good
  3. make bzImage
  4. cd include/linux
  5. ln -s autoconf.h config.h
  6. cd /whereever/vpnclient/
  7. perl -p -i -e ‘s/CHECKSUM_HW/CHECKSUM_COMPLETE/g’ interceptor.c – to replace references of CHECKSUM_HW with CHECKSUM_COMPLETE; there are only 2 to fix
  8. perl -p -i -e ‘s/skb_checksum_help(.*)/skb_checksum_help(skb)/g’ interceptor.c – to replace the 5 references to skb_checksum_help() with the proper parameters
  9. ./vpn_install – to install the Cisco VPN client

If you have a different experience don’t hesitate to let me know how it works for you.