Cable Forum - View Single Post

RainmakerRaw · 11-02-2014, 17:04

I just ran a quick port scan on GRC/ShieldsUp after shutting down my IPFire machine and switching on routing for the SH2 again for a test. With the firewall off on the SH2 the scan showed all ports as closed except 53 (DNS) which was open. Since I don't run any DNS servers I was wondering about this, and after double checking nothing was running on 53 on my local machines (eg VPN) I turned on the SH2 firewall to 'Low'. Now the following appears:

What gives? Is port 53 open by default on the SH2 or have I missed something else locally? Since even without the firewall enabled the SH2 has NAT, and UPnP is disabled, I can't see how the port could be forwarding from a local machine and it turns to stealth once the SH2 firewall is enabled. So I'm guessing it has to be the SH2 broadcasting on 53? I use Google DNS set individually per NIC btw. Thanks in advance for any ideas.

11-02-2014, 17:04	#1
RainmakerRaw Inactive Join Date: Jan 2010 Services: Gig1 Posts: 230	Port 53 open by default on SH2? I just ran a quick port scan on GRC/ShieldsUp after shutting down my IPFire machine and switching on routing for the SH2 again for a test. With the firewall off on the SH2 the scan showed all ports as closed except 53 (DNS) which was open. Since I don't run any DNS servers I was wondering about this, and after double checking nothing was running on 53 on my local machines (eg VPN) I turned on the SH2 firewall to 'Low'. Now the following appears: What gives? Is port 53 open by default on the SH2 or have I missed something else locally? Since even without the firewall enabled the SH2 has NAT, and UPnP is disabled, I can't see how the port could be forwarding from a local machine and it turns to stealth once the SH2 firewall is enabled. So I'm guessing it has to be the SH2 broadcasting on 53? I use Google DNS set individually per NIC btw. Thanks in advance for any ideas.