station and place the host public key in it. An entry for a public key in the known
hosts file would appear similar to the following example:
10.1.0.54 1024 35 15684995401867669259333946775054617325313674890836547254
15020245593199868544358361651999923329781766065830956 10825913212890233
76546801726272571413428762941301196195566782 59566410486957427888146206
519417467729848654686157177393901647793559423035774130980227370877945452
4083971752646358058176716709574804776117
3. Import Client’s Public Key to the Switch – Use the copy tftp public-key
command (page 23-11) to copy a file containing the public key for all the SSH
client’s granted management access to the switch. (Note that these clie nts must
be configured locally on the switch via the User Accounts pa ge as descr ibed on
page 6-1.) The clients are subsequently authenticated using these keys. The
current firmware only accepts public key files based on standard UNIX forma t as
shown in the following example for an RSA key:
1024 35 1341081685609893921040944920155425347631641921872958921143173880
055536161631051775940838686311092912322268285192543746031009371877211996
963178136627741416898513204911720483033925432410163799759237144901193800
609025394840848271781943722884025331159521348610229029789827213532671316
29432532818915045306393916643 steve@192.168.1.19
4. Set the Optional Parameters – On the SSH Settings page, configure the optional
parameters, including the authentication timeout, the number of retries, and the
server key size.
5. Enable SSH Service – O n t he SSH Settings page, enable the SS H s erver on the
switch.
6. Authentication – One of the following a uthent icati on met hods is empl oyed:
Password Authentication (for SSH v1.5 or V2 Clients)
a. The client sends its password to the server.
b. The switch compares the client's passwo rd to those stored in m emory.
c. If a match is found, the connection is allowed.
Note:
To use SSH with only password authentication, the host public key must still be
given to the client, either during initial connection or manually entered into the
known host file. However, you do not need to configure the client’s keys.
Public Key Authentication – When an SSH client attempts to contact the switch,
the SSH server uses the host key pair to negotiate a session key and encryption
method. Only clients that have a private key corresponding to the public ke ys
stored on the switch can access it. The following exchanges take place during
this process:
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 st ored in m emory.
c. If a match is found, the switch uses its secret k ey to ge nerat e a random
256-bit string as a challenge, encrypts this string with the user ’s p ublic key,
and sends it to the client.
6-9Configuring the Secure She
6