Forum: Ruby about Net::telnet

hi,
I use Net::telnet connecting my router,rename hosname,show current
users,but I got an error.
My code below:
<code>
require 'net/telnet'

tn = Net::Telnet.new({'Host'=> '3333::1', 'Waittime'=> '100'})
sleep 1
#tn.login()
tn.cmd("config\r\nhostname TEST\r") {|c| puts c}
sleep 1
tn.cmd("show user") {|c| puts c}
sleep 1
tn.close
</code>

but I got an error as the attachment,I don`t konw how to fix this
error.Pls help me.Thx~~~