TFTP : UDP / TCP

daghighi.navid · ‎06-14-2007

Hi,

We know that TFTP uses UDP.

But may a TFTP application send some TCP segments ?

So when we want to block traffic to access TFTP server, we should go :

... deny udp ... eq 69

... deny tcp ... eq 69 ?

Thanks,

Navid

paolo bevilacqua · ‎06-14-2007

TFPT is UDP only.

Nothing prevents an application to use TCP on port 69, but that would not work with TFTP.

bjw · ‎06-14-2007

IMHO,

If you desire to block TFTP, then why not block both TCP and UDP on port 69. Any TCP connection on well known Port 69 would smell like a bad guy or other mal-intender.

Port 69 used to be a big screen door to hackers years ago, might still have a few listeners floating around today.

Bill