Script to check various ping results

[localzuk]

Whenever our internet connection fails, I have to run through a series of checks, namely:

 

1. Check I can ping the edge router in school

2. Check I can ping the headend router at RM

3. Check I can ping the DNS server/Exchange Server etc... at our LEA

4. Check I can ping the RM proxy

 

Depending on the results of the above, I will then connect through to the switch on which the edge router connects and run various pings from that.

 

Eventually, I narrow it down to

 

a) Bust switch

b) Bust edge router

c) External issue

 

Now, are there any perl gurus out there who could code up a script that checks pings and their results? Also, is it possible to script a telnet or ssh session, and running a command on that session, looking at the result it returns?

 

Cheers in advance...

[powdarrmonkey]

Whenever our internet connection fails, I have to run through a series of checks, namely:

 

1. Check I can ping the edge router in school

2. Check I can ping the headend router at RM

3. Check I can ping the DNS server/Exchange Server etc... at our LEA

4. Check I can ping the RM proxy

 

I got the LA to tell me what path traffic took to various key things (our hosted boxes, for example) and watched them with Nagios.

[localzuk]

I got the LA to tell me what path traffic took to various key things (our hosted boxes, for example) and watched them with Nagios.

 

Yeah, I do the same, but when Nagios isn't as thorough as a sequential analysis of where the problem lies. For example, recently I could ping our edge router from the nagios server, but not from the switch it was connected to... A quick reset of the switch later and it was fine. But nagios couldn't have shown that, whereas my newly created 'checklist' does. And if I can perlify it, it means I can run it as a nagios check anyway...

[powdarrmonkey]

Well no, it's never going to be a replacement for going and having a proper look, but at least I could glance at it and see that intermediate stuff was working and so probably wasn't able to fix it.

 

Edit: oh, I should read your post more carefully. I monitored key switchgear along the way, so that I had a path to the edge not just the edge router.

Edited January 7, 2009 by powdarrmonkey

[kmount]

Straight answer is yes, it can be done including the SSH question with the caveat that there needs to be an ability to load an sshkey onto the "host" you wish to ssh into to perform commands as I'd be a bit wary of throwing the password in cleartext at it.

 

I could write that in bash now, but I'm on the track with perl hopefully this week and next to see whether I could do that also.

 

Sounds useful

[jedmondson]

If this can be done please share the code would find it useful

[Randi11]

localzuk:

 

I am NOT a scripting guru, but was able to put together for you a ping script quickly. (I am not a networking/systems guru either - just know a little bit of scripting.)

 

Here is the script. Feel free to use it, edit it, make it better, etc. It is in biterscripting - you can use any language. (I like biterscripting because you can write a script in no time at all.)

 

# PING SCRIPT
# Following are passed as input arguments. They are ip addresses.
var str edge, headend, server

# Ping edge first. We will look for the lost packets in the response.
var str reply
var int lost
system ping ("\""+$edge+"\"") > $reply
# Parse the reply to get number of lost packets. That number is between "Lost = " and " ".
stex "^Lost = ^]" $reply > null
stex "[^ ^" $reply > null
set $lost = makeint(str($reply))

if ($lost > 0)
 echo "EDGE ROUTER DOWN"
else
 # Edge router is OK.
 # Check the headend router the same way.
 .
 .
 .
 if ($lost > 0)
   echo "HEADEND ROUTER DOWN"
 else
   # Headend router is ok.
   # Check the server the same way.
   .
   .
   .
   if ($lost > 0)
     echo "SERVER DOWN"
   else
     .
     .
     .
     etc.
   endif # Check for server
 endif # Check for headend router
endif # Check for edge router

 

To run the script, save it in file ping.txt. Then call it using following command.

 

script ping.txt edge("1.2.3.4") headend("5.6.7.8") server("9.0.1.2")

 

Very simple, really. You can also use URLs instead of IP addresses, such as "http://www.somesite.com". If you don't have biterscripting - it is free - download and install it from http://www.biterscripting.com. You can also follow their installation directions. (For your purposes, I don't think you need to do anything other than just install, then call the ping script as above.)

 

Randi