Health Check Link Aggregation

The Health Check LAG (Link Aggregation Group) application allows you to create a link aggregation group where individual member links can monitor a particular TCP/IP address and TCP port.

When connectivity to the TCP/IP address and TCP port fails, the member link is removed from the link aggregation group.

Establishing the status of a TCP connectivity is based on standard TCP socket connections. As long as the switch can establish a TCP connection to the target switch and TCP port, the connection is considered up. The TCP connection will retry based on the configured frequency and miss settings.

A typical use case for this application is when a user wishes to connect each member link to a Security Server to validate traffic. Each member link of the Health Check LAG is connected to an individual Security Server. The LAG is added to a VLAN on the same subnet as the Security Server IP addresses they wish to monitor. Each member port is configured to monitor a particular IP address and TCP port. The Health Check LAG application attempts to do a TCP connect to each IP/TCP port through each member port. The Health Check LAG, by virtue of the sharing algorithm, will load balance traffic across the member links. If a TCP connection cannot be established through the member link, the port is removed from the aggregator and traffic through that particular link is redistributed to the other LAG member links.

The following figure displays an example of a Health Check LAG.

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Health Check LAG Example
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