NTP

Introduction

The Network Time Protocol (NTP) service can be used to keep the appliance clock accurate. This is important for recording accurate timestamps in the filesystem, and for protocol authentication. The appliance records times using the UTC timezone. The times that are displayed in the BUI use the timezone offset of your browser.

Properties

Changing services properties is documented in the BUI and CLI sections of Services.

Validation

If an invalid configuration is entered, a warning message is displayed and the configuration is not committed. This will happen if:

• A multicast address is used but no NTP response is found.

• An NTP server address is used, but that server does not respond properly to NTP.

Authentication

To prevent against NTP spoofing attacks from rogue servers, NTP has a private key encryption scheme whereby NTP servers are associated with a private key that is used by the client to verify their identity. These keys are not used to encrypt traffic, and they are not used to authenticate the client -- they are only used by the NTP client (that is, the appliance) to authenticate the NTP server. To associate a private key with an NTP server, the private key must first be specified. Each private key has a unique integer associated with it, along with a type and key. The type must be one of the following:

After the keys have been specified, an NTP server can be associated with a particular private key. For a given key, all of the key number, key type and private key values must match between client and server for an NTP server to be authenticated.

BUI

To add NTP authentication keys in the BUI, click on the plus icon and specify the key number, type and private value for the new key. After the key has been added, it will appear as an option next to each specified NTP server.

CLI

Under configuration services ntp, edit authorizations with the authkey command:

clownfish:configuration services ntp> authkey
clownfish:configuration services ntp authkey>

From this context, new keys can be added with the create command:

clownfish:configuration services ntp authkey> create
clownfish:configuration services ntp authkey-000 (uncommitted)> get
                        keyno = (unset)
                         type = (unset)
                          key = (unset)
clownfish:configuration services ntp authkey-000 (uncommitted)> set keyno=1
                        keyno = 1 (uncommitted)
clownfish:configuration services ntp authkey-000 (uncommitted)> set type=A 
                         type = A (uncommitted)
clownfish:configuration services ntp authkey-000 (uncommitted)> set key=coconuts
                          key = ******** (uncommitted)
clownfish:configuration services ntp authkey-000 (uncommitted)> commit
clownfish:configuration services ntp authkey> 

To associate authentication keys with servers via the CLI, the serverkeys property should be set to a list of values in which each value is a key to be associated with the corresponding server in the servers property. If a server does not use authentication, the corresponding server key should be set to 0. For example, to use the key created above to authenticate the servers "gefilte" and "carp":

clownfish:configuration services ntp> set servers=gefilte,carp
                      servers = gefilte,carp (uncommitted)
clownfish:configuration services ntp> set serverkeys=1,1
                   serverkeys = 1,1 (uncommitted)
clownfish:configuration services ntp> commit
clownfish:configuration services ntp>

To authenticate the server "gefilte" with key 1, "carp" with key 2 and "dory" with key 3:

clownfish:configuration services ntp> set servers=gefilte,carp,dory
                      servers = gefilte,carp,dory (uncommitted)
clownfish:configuration services ntp> set serverkeys=1,2,3
                   serverkeys = 1,2,3 (uncommitted)
clownfish:configuration services ntp> commit
clownfish:configuration services ntp>

To authenticate the servers "gefilte" and "carp" with key 1, and to additionally have an unauthenticated NTP server "dory":

clownfish:configuration services ntp> set servers=gefilte,carp,dory
                      servers = gefilte,carp,dory (uncommitted)
clownfish:configuration services ntp> set serverkeys=1,1,0
                   serverkeys = 1,1,0 (uncommitted)
clownfish:configuration services ntp> commit
clownfish:configuration services ntp>

BUI Clock

To the right of the BUI screen are times from both the appliance (Server Time) and your browser (Client Time). If the NTP service is not online, the "SYNC" button can be clicked to set the appliance time to match your client browser time.

Tips

If you are sharing filesystems using SMB, the client clocks must be synchronized to within five minutes of the appliance clock to avoid user authentication errors. One way to ensure clock synchronization is to configure the appliance and the SMB clients to use the same NTP server.

To view service logs, refer to the Logs section from Services.

Tasks

NTP Tasks

BUI Clock Synchronization

This will set the appliance time to match the time of your browser.

1. Disable the NTP service.
2. Click the "SYNC" button.