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Beginner

Results of NMAP scan on IOS Zone Based Firewalls: Questions

I have a few 2911 ISR's running on my network that are running zone based or CBAC firewalls depending on when it was deployed.  I am testing both configurations the following 2 NMAP scans with the following results which are puzzling.

1. TCP SYN Scan- shows that all ports are filtered. (Yay!)

2. TCP Connect Scan- Shows 2 ports open. (Boo!)

  1. 80/HTTP 
  2. 1720/H.323/Q.931.

I feel confident in my configurations but am looking for council to help me understand why these come back open on a TCP Connect Scan.

So just to be sure my configs are solid, I have verified this to be the case on both a CBAC configuration with ACL denying just about everything from the outside and on a Zone Based firewall.  I have also used shut down the IP http server and secure server.  Doing a "Show IP HTTP Server status" shows it is disabled.  I even ran the Cisco "Auto secure" command as an additional step locking it down but these ports are still showing open on a TCP connect scan. 

Should this behavior be expected?

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VIP Advisor

Any NAT configured?

Any NAT configured?

I would try upgrading to a gold star software release if you aren't running one already.  You may simply be running into an issue already resolved.

Engager

hi,

hi,

are you running NMAP from 'inside' or 'outside'?

please post sanitized config.