Sunday, March 15, 2009

Cisco's Interface Config Cache

Ever notice that doing a show run on a large 3750 Stack or a 6513 can take a (relatively) long time? Enter Cisco's Interface Config Cache:

Basically, what it does is cache the config in memory, so that your "show run"s execute a LOT faster. Normally, everytime you do show run, it has to query EVERY interface in the system to determine the config for each, and then displays it.

This command tells the IOS to cache it the first time "show run" is executed, so every subsequent "show run" is loading a cache'd copy. Every time a config change is made, the cache is cleared, to keep itself fresh.

In other words, this command won't make a difference the first time you do a "show run" after a config change, but every "show run" thereafter(until the next interface change) will be loaded from the cache and be SUPER speedy.

For the impatient, the command is:
parser config cache interface

Saturday, March 14, 2009

Sun JRE Native 64-bit Plugin support in Firefox

Finally, 64-bit Linux computing is becoming usable for the masses, I'm sure the major distros will pick up on this and make this even easier for those without patience.

Anyway, Sun's JRE 6.0 Update 12 added 64-bit support. I recommend downloading Update 14 build 03 to get the latest and greatest. (as of this writing of course)

I've not tried this in Vista 64 or XP 64bit.

Under Linux, download the 64-bit bin file, chmod it to run(I recommend the /opt directory), and it will extract and install itself. Then you only need to add a symbolic link in your firefox plugin directory to the file in the /lib/amd64 subdirectory of the newly installed JRE.

Here is what I did under Ubuntu 8.10:
cd /opt
sudo mv ~/Desktop/jre-6u14-ea-bin-b03-linux-amd64-10_mar_2009.bin ./
sudo chmod 777 jre-6u14-ea-bin-b03-linux-amd64-10_mar_2009.bin
sudo ./jre-6u14-ea-bin-b03-linux-amd64-10_mar_2009.bin
cd /usr/lib/mozilla/plugins
sudo ln -s /opt/jre1.6.0_14/lib/amd64/

Taken from:

Friday, March 6, 2009

Testing Copper Cables with Cisco Switches (TDR)

You can quickly detect any cable problems from your test with any 3560G/3750G/4500(with Gig Ports)/6500(with Gig Ports) by using the built-in IOS TDR. It will tell you the length of the cable and if there are any open pairs(and if so, where in the line they occur). This is better than running up to the location with a Fluke in hand to test cable problems.

First, you must run the test(its intrusive on the interface its being run on, so only run it on something that is OK to be unreachable for about a minute):
test cable-diagnostics tdr interface <InterfaceName>

After it completes, all you have to do is view the result:
show cable-diagnostics tdr interface <InterfaceName>

See the link below for the full scoop from Cisco: