Breaking a Trace Route in Cisco Routers and Switches

This is a pretty useful piece of information that will make your network troubleshooting go quicker. I find it kind of hard to remember as it breaks with convention. You can’t use CTRL+Break, or any other normal ways to break a trace, ping or whatever in windows (CTRL+Z, CTRL+ESC, CTRL+C).

How to Break a Trace or Ping in Cisco Routers and Switches

Step 1 – Hit Control+Shift+6. That’s it. Some routers seem to want you to do it twice.

Adding ShoreTel Option 156 to Old Cisco Routers

Found this in my book of notes today. Thought I’d pass this along. There’s a lot of old Cisco Routers out there that configured as DHCP servers on small networks with ShoreTel phones on them. Here’s how to set them up to auto-configure your phones.

I’m assuming the router’s DHCP pool has already been set up. You can use SDM, SDM Express, or any number of other GUI’s to do this. For the options though you have to be in command line. I’m also assuming a basic knowledge of Cisco Routers.

Step 1- Telnet or console into the router. Get into configuration mode (type en, enter your password, then type config t and enter your password if it asks.)

Step 2 – Type: ip dhcp pool [pool name] (might check your running config to get this). If you set the pool up in SDM it should be something like sdm-pool1.

Step 3 – Type: option 156 [ASCII] “ftpservers=xxx.xxx.xxx.xxx”. You may or may not be required to type in the ASCII option, newer routers need it, older routers don’t. Entirely dependent on your IOS version. Also if you have VLANS, set up your string accordingly, the router can pass this information on as well.

If you have older versions of ShoreTel I think the option is 66 for the ftp server. That option will work for newer versions too, but 156 is the more flexible.

Step 4 – Exit out of config mode, save your work and reboot your phones. They should now be getting FTP server information.