Siemens RUGGEDCOM ROX II User Manual page 449

RUGGEDCOM ROX II
CLI User Guide
Traditionally, GRE tunnels are stateless, meaning that remote endpoints retain no information about one another.
As a result, an endpoint will not know when the other endpoint becomes unreachable and continue sending
frames, even though the other end is unable to receive them.
With keepalive messages enabled, RUGGEDCOM ROX II will send keepalive messages to the other endpoint and
wait for a response. If a response is not received before the next message is scheduled to be sent, it begins to
count the number of consecutive messages sent that did not receive a reply. After so many failures to reply,
the other endpoint is considered unreachable and a Link Down alarm is raised. This is the cue to the network
administrator to bring down the GRE tunnel and investigate.
By default, keepalive messages are sent every 10 seconds and the remote endpoint has three opportunities to
reply. These thresholds are user configurable.
To enable or disable keepalive messages for a GRE tunnel, do the following:
1. Make sure the CLI is in Configuration mode.
2. Enable or disable keepalive messages by typing:
Enable
tunnel gre name gre-keepalives enabled
Disable
no tunnel gre name gre-keepalives enabled
Where name is the interface name of the GRE tunnel network. The interface name must start with a lowercase
letter, but may contain any combination of lowercase letters, numbers and dashes up to a maximum of 10
characters. The prefix gre- will be added to this interface name.
3. If keepalive messages are enabled, configure the following parameters:
Parameter
interval { interval }
retries { retries }
Type commit and press Enter to save the changes, or type revert and press Enter to abort.
4.
Section 12.7.6
Deleting a GRE Tunnel
To delete a GRE tunnel, do the following:
1. Make sure the CLI is in Configuration mode.
2. Delete the GRE tunnel by typing:
no tunnel gre name
Where:
• name is the name of the GRE tunnel
Type commit and press Enter to save the changes, or type revert and press Enter to abort.
3.
Deleting a GRE Tunnel
Synopsis: A 16-bit unsigned integer between 1 and 32767
Default: 10
The interval in second(s) at which keepalive messages are sent to the remote endpoint.
Synopsis: An 8-bit unsigned integer between 1 and 255
Default: 3
The number of keepalive message the remote endpoint can ignore before it is considered
unreachable.
Tunneling and VPNs
Description
Chapter 12
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