> Source: [sk31336](https://support.checkpoint.com/results/sk/sk31336)

# sk31336 - Using Monitor Interface Link State feature to improve ClusterXL interface-failure-detection ability

| Property | Value |
|----------|-------|
| Solution ID | sk31336 |
| Date Created | 2005-11-20 |
| Last Modified | 2020-07-13 |
| Technical Level | Advanced |
| Products | Security Gateway |
| Versions | R82.10, R82, R81.20 |
| OS | Gaia |

## Symptoms

- ClusterXL is unable to conclusively detect and determine the cluster member that is associated with the failure of a monitored interface (either a cluster interface, a Sync interface, or a monitored private interface). The cluster state presents as Active Attention/Down. But the "down" cluster member might actually be the member with the interface that remains connected.

## Cause

Inconclusive ClusterXL detection is associated with the following scenario: A monitored interface in a two-member ClusterXL cluster is connected to a subnet. This subnet contains no other, directly connected network devices that can reply to ICMP Requests (Ping), as used by ClusterXL in its probing. There is also no other traffic from any other subnets transferring through these cluster members. The monitored interface fails. As a result of the disconnected interface, the cluster members cannot receive CCP packets from each other on that network. Furthermore, no other device on the subnet replies to any cluster member's ICMP probing. These conditions result in the cluster's inability to conclusively determine the cluster member associated with the failed interface.

## Solution

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