Configuring Tunnel Keepalives

The controller determines the status of a GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel by sending periodic keepaliveSignal sent at periodic intervals from one device to another to verify that the link between the two devices is working. If no reply is received, data will be sent by a different path until the link is restored. A keepalive can also be used to indicate that the connection should be preserved so that the receiving device does not consider it timed out and drop it. frames on the Layer-2 or Layer-3 GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel. When you enable tunnel keepalives, the tunnel is considered down when the keepalives fail repeatedly.

If you configure a firewallFirewall is a network security system used for preventing unauthorized access to or from a private network. policy rule to redirect traffic to the tunnel, traffic is not forwarded to the tunnel until it is up. When the tunnel comes up or goes down, an SNMPSimple Network Management Protocol. SNMP is a TCP/IP standard protocol for managing devices on IP networks. Devices that typically support SNMP include routers, switches, servers, workstations, printers, modem racks, and more. It is used mostly in network management systems to monitor network-attached devices for conditions that warrant administrative attention.  trap and logging message is generated. The remote endpoint of the tunnel does not need to support the keepaliveSignal sent at periodic intervals from one device to another to verify that the link between the two devices is working. If no reply is received, data will be sent by a different path until the link is restored. A keepalive can also be used to indicate that the connection should be preserved so that the receiving device does not consider it timed out and drop it. mechanism.

The controller sends keepaliveSignal sent at periodic intervals from one device to another to verify that the link between the two devices is working. If no reply is received, data will be sent by a different path until the link is restored. A keepalive can also be used to indicate that the connection should be preserved so that the receiving device does not consider it timed out and drop it. frames at 60-second intervals by default and retries keepalives up to three times before the tunnel is considered down. You can change the default values of the intervals:

For the interval, specify a value between 1 and 86400 seconds.

For the retries, specify a value between 1 and 30.

To interoperate with Cisco network devices, use the cisco option.

You can configure tunnel keepalives using the WebUI or CLICommand-Line Interface. A console interface with a command line shell that allows users to execute text input as commands and convert these commands to appropriate functions..

Configuring ICMP based GRE Tunnels

Starting from ArubaOS 8.5.0.0, GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel will support ICMPInternet Control Message Protocol. ICMP is an error reporting protocol. It is used by network devices such as routers, to send error messages and operational information to the source IP address when network problems prevent delivery of IP packets. based health-check feature to monitor the status of WANWide Area Network. WAN is a telecommunications network or computer network that extends over a large geographical distance. reachability from remote uplink. ICMPInternet Control Message Protocol. ICMP is an error reporting protocol. It is used by network devices such as routers, to send error messages and operational information to the source IP address when network problems prevent delivery of IP packets. echo requests are periodically sent through the tunnel to a user configured destination. For example in Figure 1, Controller A will send an ICMPInternet Control Message Protocol. ICMP is an error reporting protocol. It is used by network devices such as routers, to send error messages and operational information to the source IP address when network problems prevent delivery of IP packets. echo request to Controller B to ping the destination in WANWide Area Network. WAN is a telecommunications network or computer network that extends over a large geographical distance. . If Controller A does not receive ICMPInternet Control Message Protocol. ICMP is an error reporting protocol. It is used by network devices such as routers, to send error messages and operational information to the source IP address when network problems prevent delivery of IP packets. echo response , it will bring down the tunnel to Controller B and the standby tunnel to Controller C will become active. This feature helps in detecting WANWide Area Network. WAN is a telecommunications network or computer network that extends over a large geographical distance. / Internet failure and will signal the controller to pass the traffic through the secondary / standby GREGeneric Routing Encapsulation. GRE is an IP encapsulation protocol that is used to transport packets over a network. tunnel.

Figure 1  ICMP based GRE Tunnel

In the CLI

To configure ICMPInternet Control Message Protocol. ICMP is an error reporting protocol. It is used by network devices such as routers, to send error messages and operational information to the source IP address when network problems prevent delivery of IP packets. based tunnel keepalives, use the following command:

(host)[mynode](config-submode) #tunnel keepalive icmp <ipaddr> <next-hop>

<next-hop> parameter must be configured for L2 tunnels only.