tcpdump

[shazzam1]

Hello all,

I should know this by now however can't figure it so here I am where always questions are answered.

Here is my situation have build a new linux webserver with PHP , mysql and vtiger this is a custom vtiger (crm) server. Now I like to know the command in tcpdump how to troubleshoot connections from outside to the server.

thanks in advance
t

 

[Annihilannic]

What kind of problem are you trying to troubleshoot? Connection losses? Or failure to make connections in the first place?

Annihilannic.

 

[shazzam1]

both..

thanks

 

[Annihilannic]

Well, it's a bit of a needle-in-haystack situation when you don't really know what you're looking for in tcpdump output.

Just start by looking at man tcpdump and finding the options that let you specify which interface you are expecting the connections to come in on, and which port number they are connecting to. Also I recommend using the option to dump the packets to a file initially, because then you can use tcpdump again to read from that file and display the contents in various formats depending on your requirements.

Annihilannic.

 

[3t0n1c]

Can you be more specific about what doesn't work?

Are you sure it's on your box, and not elsewhere like open ports being closed, etc?

Do you have iptables (aka firewall) running on your machine?
If so, does it allow connections to be made?

Let me know how you make out!