about Telnetlib problem

[JEHERUL]

Dear All

I am trying to telnet to a Cisco router . Following is my code .

#code router.py

import getpass
import sys
import telnetlib

HOST = "router address"               # router address is ommitted for
security reason
user = raw_input("Username : ")
password = getpass.getpass()

tn = telnetlib.Telnet(HOST)

tn.read_until("Username: ")
tn.write(user + "\n")
tn.read_until("Password: ")
tn.write(password + "\n")


tn.read_until("I>")
tn.write("sh int f0/0")

print "Just to check"


print tn.read_all()

print "after read"
tn.write("exit\n")



But when I execute the program I got the following error .


Traceback (most recent call last):
  File "router.py", line 23, in ?
    print tn.read_all()
  File "/usr/lib/python2.4/telnetlib.py", line 330, in read_all
    self.fill_rawq()
  File "/usr/lib/python2.4/telnetlib.py", line 521, in fill_rawq
    buf = self.sock.recv(50)

Please help me .

Regards
-- 
Jeherul Islam
Indian Institute of Information Technology and Management .
Gwalior (MP)
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