nanog mailing list archives

RE: Nipper and Cisco configuration results


From: Subba Rao <castellan2004-nsm () yahoo com>
Date: Thu, 2 Apr 2009 17:25:08 -0700 (PDT)

I did not scan the routers yet with nmap.  These results are from Nipper analysis.  None of the access lists are 
showing "port 513" as Nipper is complaining about.  The IOS version is 12.4

Subba Rao


--- On Thu, 4/2/09, Jo¢ <jbfixurpc () gmail com> wrote:

From: Jo¢ <jbfixurpc () gmail com>
Subject: RE: Nipper and Cisco configuration results
To: castellan2004-nsm () yahoo com, nanog () nanog org
Date: Thursday, April 2, 2009, 8:18 PM

What IOS version are you using? I don't see that behavior (rlogin/rsh) by
default, but I'm a few revisions behind on the latest. @ 12.2
I do see from the router: 
RCMD-4-RSHPORTATTEMPT Attempted to connect to RSHELL from 192.168.1.52
from nmaps, but theres no response to the SYN packet of the attempting IP. I
think this has been
the case since w-a-y earlier versions of IOS for logging levels but not sure
at which level.
Looks to only be logging an attempt, no session is made, sort of like a
firewall 
just letting you know there was an attempt. The router gets the request but
it falls on deaf
ears, no one home. Unless perhaps theres some other sort of flag/bit that
can be presented to 
open that connection(extremely doubtful) I don't believe theres any way to
connect. 

Perhaps turning down your logging will prevent your testing program from
reporting a false positive?
I'd snoop/sniff the traffic and see if your router is SYN/ACK-ing the
request of rlogin/rsh to be sure.

<sarcasm>And make sure their not to close to one another, incase their using
undocumented 
internal wireless units as a means to complete the connection, those Cisco
guys you know..</sarcasm>

Regards
Joe Blanchard

-----Original Message-----
From: Subba Rao [mailto:castellan2004-nsm () yahoo com] 
Sent: Thursday, April 02, 2009 6:33 PM
To: nanog () nanog org
Subject: Nipper and Cisco configuration results

I am using Nipper for verifying my Cisco configuration.  
Nipper is finding the "rlogin" service that is not in the 
configuration.  I have searched the access lists and do not 
see it anywhere.  The explanation by Nipper about this 
finding, "....Telnet protocol implemented by this 
service...." is confusing.  Here is the Nipper's output:

______________________________
Rlogin Service Settings

The Rlogin service enables remote administrative access to a 
CLI on Cisco Router Devices.  The Telnet protocol implemented 
by th service is simple and provides no encryption of the 
network communications between client and the server.  This 
section details the Rlogin settings.

Description                Setting
Rlogin Service            Enabled
Service TCP Port        513
______________________________

I have checked a few other routers where SSH was not enabled 
with the same results.

Can someone explain why Nipper is saying "Rlogin is enabled" 
when I do not see it in the configuration file?  Is there 
something else that I need to be looking at?

Thank you in advance for any help.

Subba Rao


Current thread: