We have a system which uses port 139 NetBIOS to broadcast, which in turn allows PC users to map drives to the server. BUT, our firewall team will not allow such traffic across the network. Are they being pedantic and why would they impose such restrictions.

    Requires Free Membership to View

Dear Jcowie:
NetBIOS over TCP/IP (port 139) is not secured and should be blocked from inbound or outbound access through the firewall to the Internet/DMZ for security reasons. To allow this port through the firewall is to defeat the purpose of having a firewall in the first place. Windows NT uses Port 139 for null sessions and for file sharing; Windows 2000 uses (for SMB) port 445 if port 139 is not enabled.

Hope this provided the information you needed.
Take care,
Luis

This was first published in August 2002

There are Comments. Add yours.

 
TIP: Want to include a code block in your comment? Use <pre> or <code> tags around the desired text. Ex: <code>insert code</code>

REGISTER or login:

Forgot Password?
By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy
Sort by: OldestNewest

Forgot Password?

No problem! Submit your e-mail address below. We'll send you an email containing your password.

Your password has been sent to: