Symmetricom Time Server user manual Sample information in a client ntp.keys file might look like

Extended Function Commands Chapter 4: Serial or Telnet I/O Functions

The NTP client “ntp.keys” file is identical to the one on the NTP server. For the specific keys used by the NTP server, the NTP client must have the identical line in its version of the file. You’ll want to use your own hard-to-guess key names, using random letters. The critical lines of the “ntp.keys” file are:

Id M Value

------- --------

1 M Symmetricom

2 M xyz123

where 1 and 2 are key identifiers.

The first column is the key identification number, which may range in whole positive numbers from 1 to 65,535. The second column is the type of key, which is always set to the letter M when using MD5 authentication. The third column is the private key that is ASCII text from 1 to 32 characters in length.

For maximum security, use a unique combination of 32 letters and numbers for each key identifier. For correct configuration, do not use zero as a key identifier. Zero means the key identification will not be used.

Editing the MD5 keys on the NTP Client

For NTP client authentication, the line trustedkey 1 2 in the “ntp.conf” file is required to enable the private keys 1 and 2 from the “ntp.keys” file. The line bclient is required for broadcast time packets to be processed by the NTP client. In this case, sample information from a client “ntp.conf” file might look like:

trustedkey 1 2

bclient

Sample information in a client “ntp.keys” file might look like:

1 M Symmetricom

2 M longshot

When you invoke the NTP client at the command line, use the following options:

•–b

to turn on broadcast reception

•–k /etc/ntp.keys

to specify the name and location of the keys file

•–d

for debugging.

An example command line might look like:

ntpd –d –d –d –b –k /etc/ntp.keys

After configuring all MD5 keys, carry out step 4 in the configuration procedure outlined above.

6000-100Ch4.fm Rev. D TimeVault™ User’s Manual 4-71