FTP port open on Cisco 1841

Apr 11, 2006 3 Replies
FTP port open on Cisco 1841 open original image

Hello,



I've got a brand new Cisco 1841 router for our SHDSL leased line, basic configured with nothing currently running behind it. Now I wanted to see what nmap (a unix scanning port tool) detects and surprisingly it detects that port 21 (FTP) is open as you can see here below:



% sudo nmap



Starting nmap 3.81 (

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) at 2006-04-11 23:35 CEST Interesting ports on (): (The 1662 ports scanned but not shown below are in state: closed) PORT STATE SERVICE



21/tcp open ftp

Nmap finished: 1 IP address (1 host up) scanned in 11.328 seconds


Somehow port 21 on our router's IP adresse answers but is not functional (no FTP service). Now haven't seen any FTP service in the router's configuration itself, I am wondering from where does this come and why is that ??? And how can I disable this without configuring an ACL ?



Many thanks



Regards


Here is the output of "show ip sockets":

router#show ip sockets Proto Remote Port Local Port In Out Stat TTY OutputIF 17 0.0.0.0 0 67 0 0 2211 0 17 --listen-- --any-- 123 0 0 1 0

since this will be an Internet facing router, i would suggest that you implment the IOS firewall feature.

see

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