Using NTP
Creating a broadcastclient association
To configure an NTP client as a broadcast client, consult the manufacturer's documentation.
To configure a generic NTP broadcast client with MD5 authentication, the user would upload
the ntp.keys file to the /etc directory and add the following lines to the ntp.conf file (example
values italicized):
broadcastclient
enable auth
keys
/etc/ntp.keys
trustedkey
1
The key number identified by
trustedkey
must match the key number on the SyncServer or
broadcast server.
To configure a SyncServer as a broadcast client:
1. Configure authentication. For example, use
NTP - MD5
to upload the keys file.
2. Add or edit an association on the
NTP - Conf
page.
3. For
Role
, select
Broadcast Client
.
4. For
MD5
, select the appropriate method and
Key
if needed.
5. Click the
SAVE
button.
6. Click the
RESTART
button. When the NTP daemon finishes restarting, it listens for broad-
cast messages.
Also see:
n
Working with Generic NTP Devices
(on page 160)
n
Using MD5 Keys on a SyncServer
(on page 161)
n
Using NTP Authentication
(on page 160)
AddingMulticastAssociations
NTP multicasting is similar to broadcasting, but uses a routable multicast address so that the
NTP messages can reach multiple subnets. Use the IANA-designated address for NTP mul-
ticasting, 224.0.1.1, or carefully select another non-conflicting address. Also take steps to
protect multicast messages from affecting neighboring networks.
Also see
Adding Broadcast Associations
(on page 156) and
NTP - Config
(on page
43).
Configuring the multicast server
To configure a SyncServer as a multicast server:
1. Configure authentication as described in
Using NTP Authentication
(on page 160).
For example, use
NTP - MD5
to generate and download keys to your workstation.
2. Add or edit an association on the
NTP - Conf
page.
3. For
Role
, select
Broadcast
.
4. For
Address
, enter 224.0.1.1 (or another carefully selected non-conflicting address)
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