Configuring RTR

Last Updated : Apr 26, 2013 |

About this task

For each remote device whose state you wish to monitor:

Procedure

  1. Enter rtr, followed by a number from 1 to 30, to create the RTR.

    For example:

    Gxxx-001(config)# rtr 5
Gxxx-001(config-rtr 5)#
  2. Use the type command to specify the remote device by address, and specify the probing method to be employed by the RTR probe: ICMP Echo or TCP Connection.

    If you specify a TCP Connection operation, also specify which port to probe in the remote device.

    Examples:

    Gxxx-001(config-rtr 5)# type echo protocol ipIcmpEcho 10.0.0.1
Gxxx-001(config-rtr icmp 5)#
    Gxxx-001(config-rtr 5)# type tcpConnect dest-ipaddr 147.42.11.1 dest-port 
80
Gxxx-001(config-rtr tcp 5)#
  3. Optionally, use the frequency command to specify the frequency at which RTR probes are sent.

    If you do not configure this parameter, the default value of five seconds is used.

    For example:

    Gxxx-001(config-rtr icmp 5)# frequency 2 seconds
Done!
  4. Optionally, use the dscp command to set the DSCP value in the IP header of the probe packet, thus setting the packets’ priority.

    If you do not configure this parameter, the default value of 48 is used.

    For example:

    Gxxx-001(config-rtr icmp 5)# dscp 43
Done!
  5. Optionally, use the next-hop command to specify the next-hop for the RTR probe, and bypass normal routing.

    The next-hop command is disabled by default.

    Use the next-hop command when the Branch Gateway is connected to a remote device via more than one interface, and you wish to monitor the state of one specific interface. When you specify the next-hop as the interface you wish to monitor, you ensure that the RTR will probe that interface.

    When the RTR is used to monitor a static route, a PBR next hop, or the DHCP client default route, you must specify the same next-hop for the RTR. This ensures it will be sent over the next hop it should monitor.

    If the interface is an Ethernet interface (FastEthernet not running PPPoE) or VLAN interface, specify also the interface’s MAC address.

    For example:

    Gxxx-001(config-rtr icmp 5)# next-hop interface fastethernet 10/2 
mac-address 00:01:02:03:04:05
Done!
  6. Optionally, use the source-address command to specify a source IP address, instead of using the output interface’s address.

    By default, the source-address command is disabled, and RTR probes use the output interface’s address.

    Use the source-address command when you are probing a device located on the Internet, and specify as the source-address the Branch Gateway public IP address.

    For example:

    Gxxx-001(config-rtr icmp 5)# source-address 135.64.102.5
Done!
  7. Optionally, configure the RTR parameters that determine when the state of the remote device is considered up or down.

    If you do not configure these characteristics, their default values are used:

    • Use the wait-interval command to specify how long to wait for a response from the device. When the wait-interval is exceeded, the probe is considered an unanswered probe. The default value is the current value of frequency.

    • Use the fail-retries command to specify how many consecutive unanswered probes change the state of an RTR from up to down. The default value is 5.

      Note:

      When an RTR starts running, its state is considered up.

    • Use the success-retries command to specify how many consecutive answered probes change the state of an RTR from down to up. The default value is 5.

      For example:

      Gxxx-001(config-rtr icmp 5)# wait-interval 2 seconds
Done!
Gxxx-001(config-rtr icmp 5)# fail-retries 3
Done!
Gxxx-001(config-rtr icmp 5)# success-retries 1
Done!
  8. Exit the RTR type context, and activate the RTR with the rtr-schedule command.

    To deactivate the RTR, use the no rtr-schedule command.

    For example:

    Gxxx-001(config-rtr icmp 5)# exit
Gxxx-001(config)# rtr-schedule 5 start-time now life forever

    Once an RTR’s probing method and remote device address are configured, you cannot change them. If you exit the RTR type context and you want to modify the configuration of the RTR, you can enter the RTR context using the rtr command and specifying the RTR ID. From the RTR context, you can run the various modification commands described in Steps 3 to 7.