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To configure a name for a PNNI node, use the name node-level subcommand. To return to the default value, use the no form of this command.
The value assigned by the hostname command.
The LightStream 1010 PNNI node name is distributed to all other nodes via PNNI flooding. This allows all LightStream 1010 PNNI nodes to use this node name to identify this node in the following PNNI show commands:
This command only applies to PNNI nodes.
For more information, refer to the LightStream 1010 ATM Switch Software Configuration Guide.
The following example configures the node name to be eng_1.
Note This command or some of its parameters might not function as expected in the LightStream 1010 ATM switch environment.
To name an existing network connection, use the name-connection EXEC command.
The name can be any string of up to 8 characters that does not include blanks.
The following example assigns a name to an internal adapter interface.
To allow the recovered clock to specify a particular port to provide network clocking, use the network-clock-select global configuration commands. Use the no form of this command to disable this feature.
This command applies only to SONET interfaces.
The following example shows how to configure ATM 3/0/1 as a network clock source of priority 2 and to configure ATM 0/1/0 to use network-clock mode.
| Warning Make sure a network clock-source is configured before a port uses it as its clock source, which could cause serious problems on the link. |
To create, delete, enable, or disable nodes running on this switch and to specify or change the level of a node, use the node ATM router PNNI configuration command. PNNI node configuration mode is started when this command is entered. To remove a previously set node index, use the no form of this command.
With LightStream 1010 ATM switch's autoconfiguration capabilities, a lowest-level PNNI node, with the node index 1, is automatically created and by default runs on all PNNI interfaces (including interfaces determined by ILMI to be PNNI interfaces and on interfaces configured to run PNNI).
The default level is 56, the proper level for lowest-level nodes using autoconfigured Cisco ATM addresses in a single level hierarchy.
ATM router PNNI configuration.
Currently only a single lowest-level node with node index 1 is supported.
Only a node running at the lowest level can be configured to run on an interface.
The level of a node can only be modified when the node is disabled.
Enable and disable can be used to reinitialize PNNI. For example, the node ID and peer group ID are recalculated based on the switch's first ATM address and the node-level whenever a node is enabled.
For more information, refer to the LightStream 1010 ATM Switch Software Configuration Guide.
The following example shows how to enter PNNI node configuration mode.
The following example shows how to create a lowest-level PNNI node with node index 1 at level 96 (assuming no node currently exists on this switch).
atm address
atm router pnni
show atm pnni node
To enable terminal notification about pending output from other connections, use the notify line configuration command. The no form of this command ends notification.
This command has no arguments or keywords.
The command sets a line to inform a user with multiple, concurrent Telnet connections when output is pending on a connection other than the current one.
The following example sets up notification of pending output from connections on virtual terminal lines 0 to 4.
To control access to the system's Network Time Protocol (NTP) services, use the ntp access-group global configuration command. To remove access control to the system's NTP services, use the no form of this command.
No access control (full access granted to all systems).
The ntp-access group command scans the options in the following order from least restrictive to most restrictive:
Access is granted for the first match found. If no access groups are specified, complete access is granted to all sources. If any access groups are specified, only the specified access is granted. This facility provides minimal security. If more security is desired, use the NTP authentication facility.
In the following example, the system is configured to allow itself to be synchronized by a peer from access list 99. However, the system restricts access to allow only time requests from access list 42.
To enable Network Time Protocol (NTP) authentication, use the ntp authenticate global configuration command. Use the no form of this command to disable the feature.
This command has no keywords or arguments.
Use this command if you want authentication. If this command is specified, the system does not synchronize to a system unless it carries one of the authentication keys specified in the ntp trusted-key command.
The following example enables NTP authentication.
ntp authentication-key
ntp trusted-key
To define an authentication key for Network Time Protocol (NTP), use the ntp authentication-key global configuration command. Use the no form of this command to remove the authentication key for NTP.
No authentication key is defined for NTP.
Use this command to define authentication keys for use with other NTP commands to provide a higher degree of security.
The following example sets authentication key 10 to aNiceKey.
ntp peer
ntp server
ntp trusted-key
To specify that a specific interface should send Network Time Protocol (NTP) broadcast packets, use the ntp broadcast interface configuration command. Use the no form of this command to disable this capability.
In the following example, Ethernet interface 2/0/0 is configured to send NTP version 2 packets.
ntp broadcast client
ntp broadcastdelay
To allow the system to receive NTP broadcast packets on an interface, use the ntp broadcast client interface configuration command. Use the no form of this command to disable this capability.
This command has no arguments or keywords.
Use this command to allow the system to listen to broadcast packets on an interface-by-interface basis.
In the following example, the switch synchronizes to NTP packets broadcast on Ethernet interface 2/0/0.
ntp broadcast
ntp broadcastdelay
To set the estimated round-trip delay between the switch and a Network Time Protocol (NTP) broadcast server, use the ntp broadcastdelay global configuration command. Use the no form of this command to revert to the default value.
Use this command when the switch is configured as a broadcast client and the round-trip delay on the network is other than 3000 microseconds.
In the following example, the estimated round-trip delay between the switch and the broadcast client is set to 5000 microseconds.
ntp broadcast
ntp broadcast client
| Caution Do not use this command; it is documented for informational purposes only. The system automatically generates this command as Network Time Protocol (NTP) determines the clock error and then compensates. |
As NTP compensates for the error in the system clock, it keeps track of the correction factor for this error. The system automatically saves this value into the system configuration using the ntp clock-period global configuration command. The system uses the no form of this command to revert to the default.
If a copy running-config startup-config command is entered to save the configuration to memory, this command is automatically added to the configuration. It is a good idea to perform this task after NTP has been running for a week or so; this helps NTP synchronize more quickly if the system is restarted.
To prevent an interface from receiving Network Time Protocol (NTP) packets, use the ntp disable interface configuration command. To enable receipt of NTP packets on an interface, use the no form of this command.
This command has no arguments or keywords.
This command provides a simple method of access control.
In the following example, Ethernet interface 2/0/0 is prevented from receiving NTP packets.
To configure the switch as a Network Time Protocol (NTP) master clock to which peers synchronize themselves when an external NTP source is not available, use the ntp master global configuration command. To disable the master clock function, use the no form of this command.
| Caution Use this command with extreme caution. It is very easy to override valid time sources using this command, especially if a low stratum number is configured. Configuring multiple machines in the same network with the ntp master command can cause instability in timekeeping if the machines do not agree on the time. |
By default, the master clock function is disabled. When enabled, the default stratum is 8.
Since the Cisco implementation of NTP does not support directly attached radio or atomic clocks, the switch is normally synchronized, directly or indirectly, to an external system that has such a clock. In a network without Internet connectivity, such a time source may not be available. The ntp master command is used in such cases.
If the system has ntp master configured and it cannot reach any clock with a lower stratum number, the system claims to be synchronized at the configured stratum number, and other systems synchronize to it via NTP.
Note The system clock must have been set from some source, including manually before ntp master has any effect. This protects against distributing erroneous time after the system is restarted.
In the following example, the switch is configured as an NTP master clock to which peers may synchronize.
To configure the switch's system clock to synchronize a peer or to be synchronized by a peer, use the
ntp peer global configuration command. To disable this capability, use the no form of this command.
No peers are configured by default. If a peer is configured, the default NTP version number is 3, no authentication key is used, and the source IP address is taken from the outgoing interface.
Use this command if you want to allow this machine to synchronize with the peer or vice versa. Using the prefer keyword reduces switching back and forth between peers.
If you are using the default version of 3 and NTP synchronization does not occur, try using NTP version number 2. Many NTP servers on the Internet run version 2.
In the following example, the switch is configured to allow its system clock to be synchronized with the clock of the peer (or vice versa) at IP address 131.108.22.33 using NTP version 2. The source IP address is the address of Ethernet 2/0/0.
ntp authentication-key
ntp server
ntp source
To allow the switch's system clock to be synchronized by a time server, use the ntp server global configuration command. To disable this capability, use the no form of this command.
No peers are configured by default. If a peer is configured, the default NTP version number is 3, no authentication key is used, and the source IP address is taken from the outgoing interface.
Use this command if you want to allow this machine to synchronize with the specified server. The server does not synchronize to this machine.
Using the prefer keyword reduces switching back and forth between servers.
If you are using the default version of 3 and NTP synchronization does not occur, try using NTP version number 2. Many NTP servers on the Internet run version 2.
In the following example, the switch is configured to allow its system clock to be synchronized with the clock of the peer at IP address 128.108.22.44 using NTP version 2.
ntp authentication-key
ntp peer
ntp source
To use a particular source address in Network Time Protocol (NTP) packets, use the ntp source global configuration command. Use the no form of this command to remove the specified source address.
Source address is determined by the outgoing interface.
Use this command when you want to use a particular source IP address for all NTP packets. The address is taken from the named interface. This command is useful if the address on an interface cannot be used as the destination for reply packets. If the source keyword is present on an ntp server or ntp peer command, that value overrides the global value.
In the following example, the switch is configured to use the IP address of Ethernet 2/0/0 as the source address of all outgoing NTP packets.
If you want to authenticate the identity of a system to which Network Time Protocol (NTP) synchronizes, use the ntp trusted-key global configuration command. Use the no form of this command to disable authentication of the identity of the system.
If authentication is enabled, use this command to define one or more key numbers (corresponding to the keys defined with the ntp authentication-key command) that a peer NTP system must provide in its NTP packets in order for this system to synchronize to it. This provides protection against accidentally synchronizing the system to a system that is not trusted because the other system must know the correct authentication key.
In the following example, the system is configured to synchronize only to systems providing authentication key 42 in its NTP packets.
To periodically update the calendar from Network Time Protocol (NTP), use the ntp update-calendar global configuration command. Use the no form of this command to disable this feature.
This command has no arguments or keywords.
If a switch is synchronized to an outside time source via NTP, you should periodically update the calendar with the time learned from NTP. Otherwise, the calendar tends to gradually lose or gain time. The calendar is updated only if NTP has synchronized to an authoritative time server.
In the following example, the system is configured to periodically update the calendar from the system clock.
clock read-calendar
clock update-calendar
Posted: Thu Jan 23 20:57:32 PST 2003
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