Cisco Telnet

mvip has asked for the wisdom of the Perl Monks concerning the following question:

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Re: Cisco Telnet by McA (Priest) on Aug 16, 2013 at 11:37 UTC
Checkout whether Net::Telnet::Cisco has the possiblity to define a network timeout. Update: A quick look at the manual pages let me find this: `$ok = $obj->login([Name => $username,] [Password => $password,] [Passcode => $passcode,] # for Secur-ID/XTACACS [Prompt => $match,] [Timeout => $secs,]);` [download] I would try to find a feasible value for 'Timeout'. McA	[reply] [d/l]
Re^2: Cisco Telnet by mvip (Acolyte) on Aug 19, 2013 at 11:23 UTC
Tnx for the reply ... McA i wast trying with that but not working ... i put 10 seconds for timeout but nothing the script just end stoped ....	[reply]
Re^3: Cisco Telnet by McA (Priest) on Aug 19, 2013 at 11:30 UTC
Hi, In Re: Cisco Telnet ~~David~~ is showing you how to wrap the call to `login` with an eval block to catch an exception. Then you are able to log that issue and proceed in your loop. Is that what you meant? McA	[reply] [d/l]
Re^4: Cisco Telnet by mvip (Acolyte) on Aug 21, 2013 at 05:51 UTC
Re^5: Cisco Telnet by McA (Priest) on Aug 21, 2013 at 07:19 UTC
Some notes below your chosen depth have not been shown here
Re: Cisco Telnet by ~~David~~ (Hermit) on Aug 16, 2013 at 18:46 UTC
You could always eval the login: `use Net::Telnet::Cisco; for ($i = 1; $i <= 254; $i++){ $device = "172.16.$i.251"; my $session = Net::Telnet::Cisco->new(Host => "$device", Input_log => "perllogrouter/router$i.log",); eval { $session->login('admin', 'admin') or die "Could not connect +to $device" }; if ( $@ ){ # log here #; next } #some command $session->cmd ("show running-config "); $session->close;` [download] ~~David~~	[reply] [d/l]
Re^2: Cisco Telnet by 5mi11er (Deacon) on Aug 16, 2013 at 19:42 UTC
I have scripts that do the ping first test. I like Net::Ping::External as it allows, on linux, non-root users to run the scripts. -Scott	[reply]
Re^2: Cisco Telnet by mvip (Acolyte) on Aug 19, 2013 at 11:29 UTC
Im new to perl im still reading the "Beginning of perl" book, and im not familiar with eval ... i was riding about it and i think i get the point for something... for example `use Net::Telnet::Cisco; for ($i = 1; $i <= 254; $i++){ $device = "172.16.$i.251"; my $session = Net::Telnet::Cisco->new(Host => "$device", Input_log => "perllogrouter/router$i.log",); eval { $session->login('admin', 'admin') or die "Could not connect +to $device" };` [download] in this part i understand that "for loop" make from 1 to 254 and ctr... the part of eval is execute this `{ $session->login('admin', 'admin') or die "Could not connect +to $device" };` [download] and i guess this means if it's negative or not connected `if ( $@ ){ # log here #; next }` go to the next part ... and the next part is again "for loop". So my question is how can i go the for loop again ...	[reply] [d/l] [select]
Re^2: Cisco Telnet by mvip (Acolyte) on Aug 20, 2013 at 05:37 UTC
Im new to perl im still reading the "Beginning of perl" book, and im not familiar with eval ... i was riding about it and i think i get the point for something... for example `use Net::Telnet::Cisco; for ($i = 1; $i <= 254; $i++){ $device = "172.16.$i.251"; my $session = Net::Telnet::Cisco->new(Host => "$device", Input_log => "perllogrouter/router$i.log",); eval { $session->login('admin', 'admin') or die "Could not connect +to $device" };` [download] in this part i understand that "for loop" make from 1 to 254 and ctr... the part of eval is execute this `{ $session->login('admin', 'admin') or die "Could not connect +to $device" };` [download] and i guess this means if it's negative or not connected if ( $@ ){ # log here #; next } go to the next part ... and the next part is again "for loop". So my question is how can i go the for loop again ...	[reply] [d/l] [select]
Re: Cisco Telnet by McA (Priest) on Aug 22, 2013 at 07:11 UTC
Hi, after doing all advice theoretically (I'm not a network admin), I coded a small test to see where the problem is: `1 #!/usr/bin/env perl 2 use 5.010; 3 use strict; 4 use utf8; 5 use warnings qw(all); 6 7 use local::lib 'cisco'; 8 9 use Net::Telnet::Cisco; 10 11 my $session = Net::Telnet::Cisco->new( 12 Host => "192.168.168.2", 13 Timeout => 3, 14 ); 15 $session->login(Password => 'secret');` [download] A run of that shows: `problem connecting to "192.168.168.2", port 23: connect timed-out at a +m304.pl line 11` [download] AAAAHHH, the exception is thrown on line 11. It seems that the method `new` is doing a connect to host mentioned. IMHO that's an API misdesign, but anyways. Conclusion: `eval` around the new method. reduce a problem to the minimal to find the problem. BUT: Now the interesting part. Putting an eval around the method `new` can catch the exception, but not the exception message. And that's worth another thread herein. Best regards McA	[reply] [d/l] [select]
Re^2: Cisco Telnet by mvip (Acolyte) on Aug 26, 2013 at 14:20 UTC
Hi, tnx McA i get it now ... i have put the eval in wrong place. Here is what iv done `eval { my $session = Net::Telnet::Cisco->new(Host => "$device", Input_log => "perllogrouter/router$i.log", ); $session->login(Password => $curpwd); if ($session->enable("$curpwd")) { # Execute a command @output = $session->cmd ('show running-config \| section hostname') +; print "@output\n"; print " ======================================================\n"; } $session->close; }; if ($@) {print "Error: $@\n"}` [download] before i was put the eval in "$seesion->login(password=>$curpwd);" , now its works fine ... tnx again for the help and support.	[reply] [d/l]
Re^2: Cisco Telnet by mvip (Acolyte) on Aug 26, 2013 at 14:25 UTC
i would like if its possible to write in the log file the error form eval in this code. From "perllogrouter/router$i.log"the eval error to be put there if its possible. `eval { my $session = Net::Telnet::Cisco->new(Host => "$device", Input_log => "perllogrouter/router$i.log", ); $session->login(Password => $curpwd); if ($session->enable("$curpwd")) { # Execute a command @output = $session->cmd ('show running-config \| section hostname') +; print "@output\n"; print " ======================================================\n"; } $session->close; }; if ($@) {print "Error: $@\n"}` [download]	[reply] [d/l]
Re^3: Cisco Telnet by mvip (Acolyte) on Aug 27, 2013 at 16:18 UTC
sorry for the noob questions but i done this. So here it is for shearing `if ($@) { my $logtext = 'ruterproba.txt'; open my $fh, '>>',$logtext or die "Nemoze da zapise vo $logtext poradi:$! "; print $fh "Error: $@\n"}` [download] I dont know why i start learning perl, but i have to admit i have finish great jobs with him :)) i love it and im continuing to learn more and more :) and tnx for support .....	[reply] [d/l]
Re: Cisco Telnet by Anonymous Monk on Aug 17, 2013 at 02:07 UTC
Just change errmode() to "return". See the section "What To Know Before Using" in the Net::Telnet documentation.	[reply]
Re: Cisco Telnet by Anonymous Monk on Apr 01, 2015 at 15:49 UTC
The Net::Telnet module by default dies when a timeout occurs. You should add the 'Errmode' type in the constructor: `my $ip = 'x.x.x.x'; my $session = Net::Telnet::Cisco->new( Timeout => 10, Errmode => 'retu +rn');` [download] And next, a handle for the error. In this case, the script closes the tcp session: `$session->open($ip); if($session->errmsg){ $session->close; }` [download] Check the Net::Telnet module for more info. I personally use this module to automate Cisco tasks because I have found some problems with the Net::Telnet::Cisco module.	[reply] [d/l] [select]