topic Re: python telnet client response how to decode it in Controllers

python telnet client response how to decode it

globantt — Fri, 12 Apr 2024 08:01:18 GMT

python telnet client response how to decode it I think it is a specific response as all cisco servers have the same response . What is the name of this text and how do I decrypt it '\xff\xfb\x01\xff\xfb\x03\xff\xfd\x18\xff\xfd\x1f' import socket import sys HOST = 'xxx.xxx.xxx.xxx' # this is my cisco server ip PORT = 23 import socket import gzip s = socket.socket() #Connecting using telnet s.connect((HOST,23)) a = s.recv(10000) print(str(a)) #'\xff\xfb\x01\xff\xfb\x03\xff\xfd\x18\xff\xfd\x1f'

Re: python telnet client response how to decode it

bigevilbeard — Fri, 12 Apr 2024 10:00:07 GMT

It's a series of bytes that tell the client and server what features they want to enable for the connection.

Decoding the Bytes:

\xff: This byte marks the start of a Telnet command.
\xfb: This byte indicates the "WILL" option, meaning the server is proposing to enable a feature.
\x01: This byte signifies the Echo option. With Echo enabled, the server will send back whatever it receives from the client.
\x03: This byte represents the Suppress Go Ahead (SGA) option. When enabled, the server won't send a "Go Ahead" character (usually a CR or \r) after receiving a command from the client.
\xfd: This byte marks the start of a Telnet subnegotiation (used for options with additional parameters).
\x18: This byte specifies the Echo character (typically a CR or \r).
\x1f: This byte signifies the Erase character (usually a backspace or BS).

In simpler terms:

The server is proposing to enable Echo, meaning it will echo back what the client sends.
The server also suggests disabling the "Go Ahead" signal after commands.
The server defines the Echo character (carriage return) and Erase character (backspace) if these options are negotiated.

Hope this helps.

Re: python telnet client response how to decode it

Ruben Cocheno — Fri, 12 Apr 2024 12:38:02 GMT

@globantt

Try to use netmiko