Cisco 2600 router and Telnet

[Brad Dunn]

If you were saying Blocking ALL ICMP in the middle of two routers, this
would be an instance where it might not apply. Anyway I don't think we all
need to worry about the ways people check things to much, as everyone tends
to have different drives and objectives in monitoring stuff.

b r a d  d u n n          
s y s t e m s  a d m i n i s t r a t o r
.  .  .

pretzelLogic 
Ph:  +61 8 9218 8588
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-----Original Message-----
From: Marc Powell [mailto:mpowell at ena.com] 
Sent: Friday, 2 May 2003 11:01 AM
To: Jamie Baddeley; nagios-users at lists.sourceforge.net
Subject: RE: [Nagios-users] Cisco 2600 router and Telnet


Under what circumstances wouldn't a ping check be sufficient for the same
purpose? I'm monitoring over 1700 routers in this manner and it's been
accurate for over a year.

--
Marc

-----Original Message-----
From: Jamie Baddeley [mailto:jamie.baddeley at vpc.co.nz] 
Sent: Thursday, May 01, 2003 9:57 PM
To: Marc Powell; Brad Dunn; nagios-users at lists.sourceforge.net
Subject: Re: [Nagios-users] Cisco 2600 router and Telnet

ahh, but what if one is doing telnet checks to establish reachability of the
device instead of ping checking....

hmmm. catch 22.
----- Original Message -----
From: "Marc Powell" <mpowell at ena.com>
To: "Brad Dunn" <Brad at pretzel.com.au>; <nagios-users at lists.sourceforge.net>
Sent: Friday, May 02, 2003 1:29 PM
Subject: RE: [Nagios-users] Cisco 2600 router and Telnet


> Cisco's have a limited number of VTY's available for interactive
network
> sessions (5 I think). It seems to me that the router is waiting for
the
> connection that Nagios is making to result in an actual login and not 
> timing out properly if it doesn't. This isn't a Nagios specific issue
as
> I'll bet that if you repeatedly telnet'd to the port and immediately 
> dropped the connection a number of times you'd see the same behavior.
If
> it were me I would either a) look at upgrading the current running IOS 
> on that router to see if that corrected the issue or b) not do telnet 
> checks as a telnet failure on a Cisco router is an exceedingly rare 
> occurrence that doesn't usually affect any other services the router
is
> providing.
>
> marc
>
> -----Original Message-----
> From: Brad Dunn [mailto:Brad at pretzel.com.au]
> Sent: Thursday, May 01, 2003 6:57 PM
> To: 'nagios-users at lists.sourceforge.net'
> Subject: [Nagios-users] Cisco 2600 router and Telnet
>
> Hey there, I wasn't sure if this is the best place to send this, but I 
> thought id just see if there was anyone out there who had been
involved
> with
> a similar issue.
>
> In a nutshell all my nagios runs sweet without to many problems. 
> However, the only thing I've noticed, is I have a check on telnet on a 
> Cisco 2600.
>
> This is what the check looks like.
>
> [checkcommands.cfg]
> # 'check_telnet' command definition
> define command{
>         command_name    check_telnet
>         command_line    $USER1$/check_tcp -H $HOSTADDRESS$ -p 23
>         }
>
>
> [services.cfg]
> # Service definition
> define service{
>         use                             generic-service         ; Name
> of
> service template to use
>
>         host_name                       Cisco-2600
>         service_description             PING
>         is_volatile                     0
>         check_period                    24x7
>         max_check_attempts              3
>         normal_check_interval           1
>         retry_check_interval            1
>         contact_groups                  router-admins
>         notification_interval           240
>         notification_period             24x7
>         notification_options            c,r
>         check_command                   check_ping!500.0,20%!700.0,60%
>         }
>
>
> Now my only problem, is that every now and then telnet just dies, and
I
> am
> unable to login to the router remotely. Now before I was doing nagios 
> checks every so often, back when I didn't use nagios, telnet has NEVER 
> died.
I
> was
> just wondering, is it at all possible that maybe the telnet sessions 
> aren't being established or closed off properly or something like 
> that?
>
> If anyone has a better way to check the service as well id like to
hear
> it.
>
> Thanks a lot.
>
> b r a d  d u n n
> s y s t e m s  a d m i n i s t r a t o r
> .  .  .
>
> pretzelLogic
> Ph:  +61 8 9218 8588
> Fax: +61 8 9218 8599
> Lvl 9 256 adelaide tce perth wa 6000 http://www.pretzel.com.au
>
>
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_______________________________________________
Nagios-users mailing list
Nagios-users at lists.sourceforge.net
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::: Please include Nagios version, plugin version (-v) and OS when reporting any issue. 
::: Messages without supporting info will risk being sent to /dev/null