Manual Chapter : Setting Connection Limits

Applies To:

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BIG-IP LTM

  • 11.6.5, 11.6.4, 11.6.3, 11.6.2, 11.6.1
Manual Chapter

Setting Connection Limits

Overview: About connection limits

You can configure a virtual server, pool member, or node to prevent an excessive number of connection requests during events such as a Denial of Service (DoS) attack or a planned, high-demand traffic event. To ensure the availability of a virtual server, pool member, or node, you can use the BIG-IP® Local Traffic Manager™ to manage the total number of connections and the rate at which connections are made.

When you specify a connection limit, the system prevents the total number of concurrent connections to the virtual server, pool member, or node from exceeding the specified number.

When you specify a connection rate limit, the system controls the number of allowed new connections per second, thus providing a manageable increase in connections without compromising availability.

Limiting connections for a virtual server, pool member, or node

You can improve the availability of a virtual server, pool member, or node by using the BIG-IP® Local Traffic Manager™ to specify a connection limit and a connection rate limit.
  1. On the Main tab, expand Local Traffic, and then click Virtual Servers, Pools, or Nodes.
  2. Click the name of the virtual server, pool, or node you want to modify.
  3. For virtual servers only, from the Configuration list, select Advanced.
  4. In the Connection Limit field, type a number that specifies the maximum number of concurrent open connections.
  5. In the Connection Rate Limit field, type a number that specifies the number of new connections accepted per second for the virtual server.
  6. Click Update to save the changes.
After configuring connection and connection rate limits on a virtual server, or after configuring these limits on a pool member or node associated with a virtual server, the system controls the total number of concurrent connections and the rate of new connections to the virtual server, pool member, or node.

Implementation results

Configuring a connection limit or a connection rate limit for a virtual server, pool member, or node prevents an excessive number of connection requests during events such as a Denial of Service (DoS) attack or a planned, high-demand traffic event. In this way, you can manage the total number of connections to a virtual server, pool member, or node, as well as the rate at which connections are made. When you specify a connection rate limit, the system controls the number of allowed new connections per second, thus providing a manageable increase in connections without compromising availability.