Setting NTP Access Authorities

Procedure

1. Run system-view

   The system view is displayed.

2. Create an ACL to filter network administrators.
   • To create an IPv4 ACL, run the acl acl-number command.
   • To create an IPv6 ACL, run the acl ipv6 acl6-number1 command.

3. Add a rule to the ACL.
   • Run the rule [ rule-id ] [ name rule-name ] { deny | permit } [ fragment-type { fragment | non-fragment | non-subseq | fragment-subseq | fragment-spe-first } | source { source-ip-address { source-wildcard | 0 | src-netmask } | any } | time-range time-name | [ vpn-instance vpn-instance-name | vpn-instance-any ] ] ^* command to create a rule for the basic ACL.
   • Run the rule [ rule-id ] [ name rule-name ] { deny | permit } [ fragment | source { source-ipv6-address { prefix-length | source-wildcard } | source-ipv6-address/prefix-length | any } | time-range time-name | [ vpn-instance vpn-instance-name | vpn-instance-any ] ] ^* command to create a rule for the basic ACL6.
   Before configuring access control rights in an ACL, check the ACL rule configuration.

   • If the ACL rule of a source IP address is set to permit, packets from the source IP address are permitted.
   • If the ACL rule of a source IP address is set to deny, packets from the source IP address are denied.
   • If a source IP address is not in an ACL rule, packets from the source IP address are denied.
   • If no rule exists in the ACL or the referenced ACL does not exist, packets from all source IP addresses are denied.

4. Run quit

   Return to the system view.

5. Run ntp-service access { peer | query | server | synchronization | limited } { { acl-number | acl-name acl-name } | ipv6 { acl6-number | acl6-name acl6-name } } ^*

   Access authority for the NTP service on the local router is configured.

   Before specifying an ACL number, make sure you have already created and configured this ACL.

   You can configure the ntp-service access command depending on the actual situation. Table 5-2 shows the detailed NTP access authorities.

   Table 5-2 Description of the NTP access authorities

   NTP Operation Mode	Limited NTP Query	Supported Devices
   Unicast NTP server/client mode	Synchronizing the client with the server	Client
   Unicast NTP server/client 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

6. Run commit

   The configuration is committed.