Communication Channels - Nortel Secure Network Access Switch 4050 User Manual

38 Chapter 1 Overview

Communication channels

Communications between the Nortel SNAS 4050 and key elements of the Nortel
SNA solution are secure and encrypted.
channels in the network.
Table 1
Communication
Between Nortel SNAS 4050 and edge
switches
Between Nortel SNAS 4050 devices in a
cluster
Between Nortel SNAS 4050 and client PC
(TunnelGuard applet)
Between Nortel SNAS 4050 and SREM
From edge switch to EPM
From EPM to edge switch
From authorized endpoint to DHCP server
Telnet or SSH can be used for management communications between remote PCs
and the Nortel SNAS 4050 devices.
About SSH
The Secure Shell (SSH) protocol provides secure and encrypted communication
between the Nortel SNAS 4050 and the network access devices, and between
Nortel SNAS 4050 devices and remote management PCs not using Telnet.
SSH uses either password authentication or public key authentication. With public
key authentication, pairs of public/private SSH host keys protect against "man in
the middle" attacks by providing a mechanism for the SSH client to authenticate
the server. SSH clients keep track of the public keys to be used to authenticate
different SSH server hosts.
SSH clients in the Nortel SNA network do not silently accept new keys from
previously unknown server hosts. Instead, they refuse the connection if the key
does not match their known hosts.
320818-A
Communication channels in the Nortel SNA network
Table 1 shows the communication
Communication protocol
SSH
TCP and UDP
SSL/TLS
SSH
SNMPv3 Inform
Telnet over SSH
UDP