Port 445, 139 traffic?

It is SMB traffic. I'm in a domain. Everytime I browse to a folder on my local computer, it sends SMB packets to and from the PDC (Domain Controller).

Is this normal? Anyone know why it is happening? I've killed all programs running and it still happens.

This might help explain a little better.

<a href=http://www.petri.co.il/what's_port_445_in_w2k_xp_2003.htm>What is this</a>

Thanks for the link. I know it is SMB traffic, but I don't understand why it sends and receives packets on every folder I browse.

okay...so now after really reading your post, I think I get something here...
You are browsing your local PC, like a My Documents folder, yet when you do your PDC is getting send/receive packets for that directory?
Is you root directory on your local computer shared?

No, in fact the windows firewall is set to block file and print sharing inbound as well. Since my computer initiates the SMB session, it doesn't block it. I guess I'll put on Zone Alarm and block it all together and see what breaks.

I think you may find what it breaks.
Are you running some sort of webtool like Webtrends? or some sort of scanner?
A program like that, from what I have read tends to send/receive a lot of "un-necessary" packets thru the network.

I have no spyware/adware type programs on my computer. I have since loaded ZoneAlarm and the traffic is being blocked with no ill-effect. I keep getting SMB sessions being dropped by ZoneAlarm from the PDC and the BDC. Pretty weird.

It's "proabably" not a bad thing per-say, but if you are half way as anal as me...you don't like anything un-necessary.

Do you see any degredation in your browsing capabilities with Zone Alarm blocking the packets versus ZA disabled?

What you may be seeing are broadcast packets looking for any domain controllers or other machines on the network.

Let's say your machine has the following:

IP: 192.168.1.100
Subnet Mask: 255.255.255.0

Your machine may be sending out a packet to 192.168.1.255, the entire subnet you're in, looking for other available machines. Other machines listen for this traffic, and when they receive a packet, they send out their own. This is how SMB works to discover other machines on your network. These machines then show up in 'My
Network Places.'

Try doing some testing with the command: 'net view' in Windows Command Prompt (cmd.exe) while watching your firewall.