after a couple weeks lab practice, today I connected one of my new Cisco 1811 router to an ISP ADSL line.
PPP connect went fine, after that I ran a quick scan using NMAP on the router from the outside.
Here is the result:
PORT STATE SERVICE VERSION
21/tcp open tcpwrapped
22/tcp open ssh Cisco SSH 1.25 (protocol 2.0)
1720/tcp filtered H.323/Q.931
Well, I remember I configured SSH and disabled telnet during practice in the lab. But I can't remember I did anything FTP related.
I also read FTP is disabled by default on IOS.
What I'd like to know is: what is "tcpwrapped" on port 21? I don't think it's an FTP service as I wasn't able to connect to it using an FTP client.
Windows and Linux both have onboard utilities to troubleshoot listening ports, are there similar commands for IOS? How can I find out what is listening on a specific port?
What is the recommended way to post running config on this forum? I'd like to keep my posts clear.
Thanks in advance