Submitted by
guvnor on Fri, 02/12/2010 - 12:15
Introduction
As you probably are aware the Cisco ASA is the successor to the Cisco PIX. If you are like me you are used to using the "debug packet" command for doing a lot of your connectivity trouble shooting. With the ASA you can use a command which is similar (albeit improved) version of the debug packet called "capture". As well as the new capture command the Cisco ASA also has a graphic logging tool known as the Cisco ASA ASDM logging tool.
This tool is very handy for seeing what is going on your network. It can however, get very busy depending on your setup. So busy in fact that can't tell if the traffic you are looking for is in the log or not.
To remedy this the Cisco Real Time Logging tool has filter setting which lets you specify what you are looking for (See below)

The other day I was trouble shooting a connection and I specified the IP address of a mainframes within the real time monitors filter so I could see what was happening with the traffic from that particular device.
Nothing showed up - okay bad sign.

I checked the traffic with the capture command and that was showing connectivity. So why wasn't it showing up in the logs. I was pretty sure my rules were set to log.
I discovered a little gotcha - if you have set the host you are looking for in as a network object and given it a name you need to use the name you specified for it to work. Otherwise nothing shows up.
In my case I used the name UKMAINFRAME for the ip address (names and IPs changed of course) I as looking for and good news the traffic began showing up.
So in otherwords if you have set a device up as as a name (think Cisco PIX "names" command) you need to specify that in your filter for it to work properly.
See below: