Wireless/Redundant Edge Services xl Module Management and Configuration Guide WS.02.xx and greater

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Configuring the ProCurve Wireless Edge Services xl Module
Enabling Secure Network Time Protocol (NTP)
You can control four types of access to NTP resources:
■ Full Access—The Wireless Edge Services xl Module accepts all messages
from devices permitted by the associated ACL and will synchronize with
these devices. This is typically the type of access that you would grant
your NTP neighbors.
■ Only Control Queries—The module accepts only control queries from
devices permitted by the ACL. NTP peers might exchange both time
requests and control queries, so you should usually grant NTP peers full
access instead.
■ Server and Query Access—The module accepts both time requests and
control queries from devices permitted by the ACL, but does not synchro-
nize with these devices.
■ Only Server Access—The module only accepts time requests from these
devices. Grant this type of access to authorized NTP clients—which might
be any device in the world or only devices in your LAN.
Table 2-8 summarizes these types of access control.
Table 2-8. Controlling NTP Access
To grant no access of a particular type, leave the respective ACL ID at 0.
Field Queries That Permitted
Devices Can Send
Can the Module
Synchronize with
Permitted Devices?
Type of Devices for Which the
Access Control Is Used
Full Access Time requests and control
queries
Yes Trusted Secure NTP servers
Only Control Queries Control queries No Secure NTP servers (which might
be vulnerable to attack or less
accurate)
Server and Query Access Time requests and control
queries
No Secure NTP servers in a peer
relationship (which might be
vulnerable to attack or less
accurate)
Only Server Access Time queries No Any device on the Internet or any
device in your network