?
Solved

Cisco router - check for open ports

Posted on 2011-09-13
9
Medium Priority
?
962 Views
Last Modified: 2012-05-12
Hi There,

We currently have a Cisco 1841 router and it only accessible via telnet and we are in the process of upgrading this router and was wanting to know if anyone was able to tell me the entire command line commands to run on this router in order to find all currently open ports?


Thanks in advance
Adrian
0
Comment
Question by:Adma1
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
9 Comments
 
LVL 35

Expert Comment

by:Ernie Beek
ID: 36528826
Well you should be able to see that in the config. So use show run or show start. All ports not explicitly defined in the access lists should be closed.
0
 
LVL 10

Assisted Solution

by:SuperTaco
SuperTaco earned 664 total points
ID: 36528831
I third party tool is an easier bet for you try using NMAP (ZenMap GUI) it will give you a readout of all open ports on your network.

http://nmap.org/zenmap/
0
 
LVL 35

Expert Comment

by:Ernie Beek
ID: 36528844
You can always double check by using something like shields up : https://www.grc.com/x/ne.dll?bh0bkyd2
0
What Is Blockchain Technology?

Blockchain is a technology that underpins the success of Bitcoin and other digital currencies, but it has uses far beyond finance. Learn how blockchain works and why it is proving disruptive to other areas of IT.

 
LVL 34

Accepted Solution

by:
Istvan Kalmar earned 668 total points
ID: 36529019
server#sh ip sockets


Proto    Remote      Port      Local       Port  In Out Stat TTY OutputIF
 17 192.168.212.1     514 10.150.0.3      53786   0   0 100010   0
 17   --listen--          10.150.0.3       1975   0   0   11   0
 17 0.0.0.0             0 10.150.0.3       2228   0   0  211   0
 17 10.155.12.44       68 10.150.0.3         67   0   0 2211   0
 17 10.155.0.110    61731 10.155.0.1        161   0   0    1   0
 17   --listen--          10.150.0.3        162   0   0   11   0
 17   --listen--          10.150.0.3      57131   0   0    1   0
0
 
LVL 35

Expert Comment

by:Ernie Beek
ID: 36529812
@ikalmar: it that just like a netstat -an ?
0
 
LVL 10

Expert Comment

by:SuperTaco
ID: 36529819
yes, very similar.  I didn't recommend it, because i usually like using scanning tools.  either way will work though.
0
 
LVL 35

Expert Comment

by:Ernie Beek
ID: 36529856
Cool, didn't know that one. Had my learning experience for today :)
0
 

Author Comment

by:Adma1
ID: 36533577
Thanks everyone for your responses,

Ikalmar: when I run the sh ip sockets command I receive the following error

'xxxx'-GW0#sh ip sockets
                     ^
% Invalid input detected at '^' marker.

is there a series of commands that I need to run prior to the sh ip sockets command?

Thanks,
Adrian
0
 
LVL 2

Assisted Solution

by:tirabytes
tirabytes earned 668 total points
ID: 37091240
Try: sh control-plane host open-ports

Or you can do it by checking both inbound nat and accesslist on your internet facing interface (if there is any).

sh conf | inc ip nat inside
or
sh ip nat trans

&

sh access-list



0

Featured Post

ATEN's HDBaseT Presentation at InfoComm 2017

Hear ATEN Product Manager YT Liang review HDBaseT technology, highlighting ATEN’s latest solutions as they relate to real-world applications during her presentation at the HDBaseT booth at InfoComm 2017.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Is your computer hacked? learn how to detect and delete malware in your PC
Keystroke loggers have been around for a very long time. While the threat is old, some of the remedies are new!
This video gives you a great overview about bandwidth monitoring with SNMP and WMI with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're looking for how to monitor bandwidth using netflow or packet s…
Monitoring a network: why having a policy is the best policy? Michael Kulchisky, MCSE, MCSA, MCP, VTSP, VSP, CCSP outlines the enormous benefits of having a policy-based approach when monitoring medium and large networks. Software utilized in this v…

718 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question