Cisco Cisco Expressway メンテナンスマニュアル
Authentication
method
method
Description
Symmetric key
Symmetric key authentication. When using this method a Key ID, Hash method and Pass phrase
must be specified. The values entered here must match exactly the equivalent settings on the
NTP server. You can use the same symmetric key settings across multiple NTP servers. However,
if you want to configure each server with a different pass phrase, you must also ensure that each
server has a unique key ID.
must be specified. The values entered here must match exactly the equivalent settings on the
NTP server. You can use the same symmetric key settings across multiple NTP servers. However,
if you want to configure each server with a different pass phrase, you must also ensure that each
server has a unique key ID.
Private key
Private key authentication. This method uses an automatically generated private key with which to
authenticate messages sent to the NTP server.
authenticate messages sent to the NTP server.
Displaying NTP status information
The synchronization status between the NTP server and the Expressway is shown in the Status area as follows:
■
Starting: the NTP service is starting.
■
Synchronized: the Expressway has successfully obtained accurate system time from an NTP server.
■
Unsynchronized: the Expressway is unable to obtain accurate system time from an NTP server.
■
Down: the Expressway's NTP client is not running.
■
Reject: the NTP service is not accepting NTP responses.
Note that updates may take a few minutes to be displayed in the status table.
Other status information available includes:
Field
Description
NTP server
The actual NTP server that has responded to the request. This may be different to the NTP server
in the NTP server address field.
in the NTP server address field.
Condition
Gives a relative ranking of each NTP server. All servers that are providing accurate time are given a
status of Candidate; of those, the server that the Expressway considers to be providing the most
accurate time and is therefore using shows a status of sys.peer.
status of Candidate; of those, the server that the Expressway considers to be providing the most
accurate time and is therefore using shows a status of sys.peer.
Flash
A code giving information about the server's status.
00 ok
means there are no issues. See the
for a complete list of codes.
Authentication Indicates the status of the current authentication method. One of ok, bad or none. none is
specified when the Authentication method is Disabled.
Event
Shows the last event as determined by NTP (for example reachable or sys.peer)
Reachability
Indicates the results of the 8 most recent contact attempts between the Expressway and the NTP
server, with a tick indicating success and a cross indicating failure. The result of the most recent
attempt is shown on the far right.
server, with a tick indicating success and a cross indicating failure. The result of the most recent
attempt is shown on the far right.
Each time the NTP configuration is changed, the NTP client is restarted and the Reachability field
will revert to all crosses apart from the far right indicator which will show the result of the first
connection attempt after the restart. However, the NTP server may have remained contactable
during the restart process.
will revert to all crosses apart from the far right indicator which will show the result of the first
connection attempt after the restart. However, the NTP server may have remained contactable
during the restart process.
Offset
The difference between the NTP server's time and the Expressway's time.
Delay
The network delay between the NTP server and the Expressway.
Stratum
The degree of separation between the Expressway and a reference clock.
1
indicates that the NTP
server is a reference clock.
47
Cisco Expressway Administrator Guide
Network and System Settings