Cisco Cisco Expressway Maintenance Manual
Note: SNMP is disabled by default, because of the potentially sensitive nature of the information involved.
Do not enable SNMP on an Expressway on the public internet or in any other environment where you do not
want to expose internal system information.
Do not enable SNMP on an Expressway on the public internet or in any other environment where you do not
want to expose internal system information.
Configuring time settings
The
Time
page (
System > Time
) is used to configure the Expressway's NTP servers and to specify the
local time zone.
An NTP server is a remote server with which the Expressway synchronizes in order to ensure its time is
accurate. The NTP server provides the Expressway with UTC time.
accurate. The NTP server provides the Expressway with UTC time.
Accurate time is necessary for correct system operation.
Configuring the NTP servers
To configure the Expressway with one or more NTP servers to be used when synchronizing system time,
enter the Address of up to five servers in one of the following formats, depending on the system's DNS
settings (you can check these settings on the
enter the Address of up to five servers in one of the following formats, depending on the system's DNS
settings (you can check these settings on the
DNS
page,
System > DNS
):
n
if there are no DNS servers configured, you must use an IP address for the NTP server
n
if there are one or more DNS servers configured, you can use an FQDN or IP address for the NTP server
n
if there is a DNS Domain name configured in addition to one or more DNS servers, you can use the
server name, FQDN or IP address for the NTP server
server name, FQDN or IP address for the NTP server
Three of the Address fields default to NTP servers provided by Cisco.
You can configure the Authentication method used by the Expressway when connecting to an NTP server.
Use one of the following options for each NTP server connection:
Use one of the following options for each NTP server connection:
Authentication
method
method
Description
Disabled
No authentication is used.
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.
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.
Private key
Private key authentication. This method uses an automatically generated private key with which
to authenticate messages sent to the NTP server.
to 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:
n
Starting: the NTP service is starting.
n
Synchronized: the Expressway has successfully obtained accurate system time from an NTP server.
n
Unsynchronized: the Expressway is unable to obtain accurate system time from an NTP server.
Cisco Expressway Administrator Guide (X8.1.1)
Page 37 of 343
Network and system settings
Network services