In An Introduction to Logs for Newbies: Pt. 1, I took a look at basic log accessing and monitoring.In this one we will take a look at some more advanced logging, but don't worry, you don't need a chainsaw!
First, we will take a look at searching logs using grep. If you want to look for an entry for, say, eth0, you would type:
grep eth0 /var/log/*
This will show you all log entries relating to eth0, which will look somewhat like this:
/var/log/warn:Apr 16 20:20:48 linux-vqbm dhcpcd: