Ip ssh authentication-retries – Brocade Communications Systems Brocate Ethernet Access Switch 6910 User Manual

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168

Brocade 6910 Ethernet Access Switch Configuration Guide

53-1002581-01

Secure Shell

9

Authenticating SSH v1.5 Clients

a. The client sends its RSA public key to the switch.

b. The switch compares the client's public key to those stored in memory.

c. If a match is found, the switch uses its secret key to generate a random 256-bit string as a

challenge, encrypts this string with the user’s public key, and sends it to the client.

d. The client uses its private key to decrypt the challenge string, computes the MD5

checksum, and sends the checksum back to the switch.

e. The switch compares the checksum sent from the client against that computed for the

original string it sent. If the two check sums match, this means that the client's private key
corresponds to an authorized public key, and the client is authenticated.

Authenticating SSH v2 Clients

a. The client first queries the switch to determine if DSA public key authentication using a

preferred algorithm is acceptable.

b. If the specified algorithm is supported by the switch, it notifies the client to proceed with

the authentication process. Otherwise, it rejects the request.

c. The client sends a signature generated using the private key to the switch.

d. When the server receives this message, it checks whether the supplied key is acceptable

for authentication, and if so, it then checks whether the signature is correct. If both checks
succeed, the client is authenticated.

NOTE

The SSH server supports up to eight client sessions. The maximum number of client sessions
includes both current Telnet sessions and SSH sessions.

The SSH server can be accessed using any configured IPv4 or IPv6 interface address on the switch.

ip ssh authentication-retries

This command configures the number of times the SSH server attempts to reauthenticate a user.
Use the no form to restore the default setting.

Syntax

ip ssh authentication-retries count

no ip ssh authentication-retries

count – The number of authentication attempts permitted after which the interface is
reset. (Range: 1-5)

Default Setting

3

Command Mode

Global Configuration

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