Setting NTP Access Authorities

This section describes how to configure access permission control to restrict certain NTP requests.

Context

When receiving an access request packet, the NTP server matches the request packet with the access authority in descending order (from peer, server, synchronization, query to limited). The first matched authority takes effect.

Procedure

Access the system view.
```
system-view
```

Set the access permission for the NTP service on the FW.

ntp-service access { peer | query | server | synchronization | limited } { acl-number | ipv6 acl6-number } *

Where the ntp-service access command is run depends on the actual situations.

Table 1 shows the detailed NTP access authorities.

**Table 1** Description of the NTP access authorities
NTP Operation Mode	Limited NTP Query	Supported Devices
Unicast NTP client/server mode	Synchronizing the client with the server	Client
Unicast NTP client/server mode	Clock synchronization request from the client	Server
NTP peer mode	Clock synchronization with each other	Symmetric active end
NTP peer mode	Clock synchronization request from the active end	Symmetric passive end
NTP multicast mode	Synchronizing the client with the server	NTP multicast client
NTP broadcast mode	Synchronizing the client with the server	NTP broadcast client
NTP manycast client mode	Synchronizing the client with the server	NTP manycast client
NTP manycast client mode	Clock synchronization request from the client	NTP manycast server