nmap from the router

[Gideon Goddard]

Hi,

A colleague just told me he was able to do a nmap from a router to know which host and services associated the router was able to "view" on the network.

But when connecting on IOS I don't find any nmap command:

R1#nmap
Translating "nmap"

Translating "nmap"

% Unknown command or computer name, or unable to find computer address
R1#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R1(config)#nmap
            ^
% Invalid input detected at '^' marker.

Is there other nmap-like command I do not know ?

Regards

[Jonathan Unger · Accepted solution]

There is no port scanning utility built into Cisco IOS.

The only "built in" method I am aware of to check for open ports from the router to another device on the network is to use "telnet" directed at a specific ip and port. Example "telnet 1.2.3.4 80"

However, someone has put together a tcl script which can perform nmap "like" functions called "IOSMap". I have never tried this, and I would not recommend running it on production gear, but might be good for a laugh in the lab. Give it a google if you are interested. Again though, don't run random scripts on production gear unless you understand exactly what they are doing.