From: Carcarius <heath.novak@...>
Date: 2007-12-06T12:26:17+09:00
Subject: Telnet - attempting to initiate a telnet session within an 	established telnet session

My company builds a product that has a dual slot architecture for
redundancy.  Each slot has 2 significant Ethernet interfaces; one for
network connectivity and one for connectivity between slots.  Only one
of the slots is accessible from the network at a time (the other is
meant to be a backup).  The two slots communicate via a common
Ethernet backplane and each slot has a different IP address (10.0.0.9
and 10.0.0.10).

I am trying to build a script with Ruby that allows me to first telnet
into the active slot using it's network address (easy - mission
accomplished) but then to also telnet into the backup slot over the
Ethernet backplane within the same telnet session.  I want to issue
commands in order to gather data such as uptime, disk usage, etc...

I am getting hung up on the password prompt when trying to connect to
the second slot.  I can't seem to send the password info with carriage
return so I can gain access to the second slot and issue additional
commands.

The code I have written is in the testing phase and is clearly not
perfect.

Here is my code:

require 'net/telnet'

top_node = ARGV[0]

tn = Net::Telnet::new( "Host" => top_node,
                              "Timeout" => 10,
                              "Prompt" => /[$%#>] \z/n)
 tn.login("root", "lab") { |c| print c }
 tn.cmd("date") { |c| print c }
 print ARGV[0]
 print " - "
 tn.cmd("./uptime") { |c| print c }
 test = tn.cmd("ifconfig eth0 | ifconfig eth0 | awk '/inet addr:/
{print $2 }'")

 if test.include?("addr:10.0.0.9")
    tnbackup = "10.0.0.10"
 else
    tnbackup = "10.0.0.9"
 end

 print "\n\nTelnetting to Backup HFM " + "(" + tnbackup + ")\n\n"

 tn.cmd("telnet " + tnbackup + " -l root") { |c| print c }

 tn.waitfor(/Password:\s*/im) { |c| print c }
 tn.puts("lab")
 tn.cmd("ifconfig eth0 | ifconfig eth0 | awk '/inet addr:/ {print
$2 }'") { |c| print c }
 tn.cmd("exit") { |c| print c }
 tn.close

Has anyone successfully telnet into other devices from within an
established telnet session?  Let me know if I am not clear with my
problem and if I need to clarify it more.

Any help is greatly appreciated.

Thanks,

Heath