To those saying Denial of Service attack, you misread him. The OP is likely old school and is referring to Command Prompt as Dos, remember good old MS Dos? http://en.wikipedia.org/wiki/MS-DOS. The actual commands are: netstat, tracert, ping. There is nothing denial of service attack like in this.

That said, this is a bit odd, because the servers are on the same network... If you have a bad connection to one, you will have a bad connection to all on that network as it travels the same path so these commands are not going to give you very good results that would be different from you realizing you're on a popular server. Character creation during peak will tell you which server is most busy and you can then decide which to go to.

You will not get lag on 1 server and not on another through the simple fact of your own connection to that server, the lag comes from how popular that server is that results in it being overloaded with congestion. This means you might think X server is good, but it might not be X Servers peak time where as Y server might be bad but thats because its peak time or most congested was at the time you did these tests, but do you play at that time? Was it common for it to hit that congestion, lots of variables.