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Network Parameters
Network Time Protocol (NTP)
The Network Time Protocol (NTP) is a protocol that synchronizes computer clocks over the Internet. Devices that
support NTP contact a known public time server to periodically retrieve the correct date and time. See
http://www.ntp.org/
for more information on this protocol.
By default, the AP boots up using January 1, 1970 as the date and 00:00:00 as the time. The AP does not necessarily
need the correct date and time but you may want to the AP to report the correct date and time if you intend to enable
the
Logging
(Syslog) or
Credit Card Mirroring
functionality. Note that the AP’s
System Status
alarms are reported in
terms of the AP’s
Up Time
and not in terms of standard date and time.
From the
NTP Server Configuration
screen, you can configure the AP-2500 to contact a network time server to
retrieve the correct time and date each time the AP is turned on or rebooted. By default, NTP is disabled. If you want to
the AP to use the Network Time Protocol (NTP) to retrieve the time over the Internet, keep in mind the following:
•
The AP will only contact a time server during boot-up. Therefore, you need to reboot the AP after configuring this.
•
The AP must have a connection to the Internet to retrieve the date and time.
— If the AP cannot communicate with a time server during boot-up, it will generate a major severity alarm,
which is reported in the
System Status
screen as “No response from SNTP server.” SNTP stands for
Simple Network Time Protocol (a simplified version of the Network Time Protocol defined in RFC 2030 at
http://www.rfc-editor.org/
).
•
See
http://www.ntp.org/
to identify the IP addresses for public time servers in your area.
You can also manually set the date and time from the NTP Server Configuration screen. However, if NTP is disabled,
the AP will revert back to its default time (January 1, 1970 00:00:00) the next time it is rebooted (in other words, the AP
does not store the date and time in non-volatile memory).
See
Configure the Date and Time
for step-by-step instructions for configuring the NTP parameters.
Filtering
The Access Point’s Packet Filtering features help control the amount of traffic exchanged between the wired and
wireless networks. There are two sub-categories under the Filtering heading.
•
Ethernet Protocol
•
Static MAC
Ethernet Protocol
The Ethernet Protocol Filter blocks or forwards packets based on the Ethernet protocols they support.
Follow these steps to configure the Ethernet Protocol Filter:
1. Configure the
Ethernet Protocol Filter Table
. This table is pre-populated with existing Ethernet Protocol Filters,
however, you may enter additional filters by specifying the appropriate parameters.
•
To add an entry, click
Add
, and then specify the
Protocol Number
and a
Protocol Name
.
—
Protocol Number:
Enter the protocol number. See
http://www.iana.org/assignments/ethernet-numbers
for a list of protocol numbers.
—
Protocol Name:
Enter related information, typically the protocol name.
