Abstract: Some embodiments provide a method of performing load balancing on client traffic sent to a cluster of servers that are associated with a common network address (e.g., for a VIP address associated with a service provided by the cluster of servers). The method assigns a cluster of two or more transparent load balancers to the common network address associated with the server cluster. The method configures at least two of these transparent load balancers as active transparent load balancers that concurrently (1) receive data message flows sent by clients directed to the common network address, (2) select one of the servers for each flow, and (3) forward each flow to the server selected for the flow without modifying a source network address (e.g., IP network address) of the flow.

Abstract: Some embodiments provide a novel method for performing network address translation to share a limited number of external source network addresses among a large number of connections. Instead of allocating an external source network address for an egressing packet just based on its internal source network address, the method of some embodiments allocates the external source network address based on the egressing packet's source network address and destination network address. This allows a limited number of external source network addresses to be re-used for different destination network address. For instance, in some embodiments, the method's network address allocation scheme allows the same 64K (e.g., 2{circumflex over (?)}16) external source ports to be used for 64K connections for each destination network address.

Abstract: Some embodiments provide a novel method for performing network address translation to share a limited number of external source network addresses among a large number of connections. Instead of allocating an external source network address for an egressing packet just based on its internal source network address, the method of some embodiments allocates the external source network address based on the egressing packet's source network address and destination network address. This allows a limited number of external source network addresses to be re-used for different destination network address. For instance, in some embodiments, the method's network address allocation scheme allows the same 64K (e.g., 2{circumflex over (?)}16) external source ports to be used for 64K connections for each destination network address.

Abstract: The method of synchronizes network address translation (NAT) records between an active gateway and a standby gateway. The method of some embodiments synchronizes NAT records of long-term data flows more frequently than those of short-term flows. Multiple data flows pass between a device at an internal source address and a device at an external destination address through the active NAT gateway. For each flow, the method generates a NAT record. The method then determines whether the data flow is a short-term flow or a long-term flow and synchronizes the NAT records of the long-term flows, but not the NAT records of the short-term flows, with the standby gateway. The method of some embodiments synchronizing NAT records more frequently when NAT records are being generated quickly relative to prior generation rates and less frequently when NAT records are being generated slowly relative to the prior generation rates.

Abstract: The method of synchronizes network address translation (NAT) records between an active gateway and a standby gateway. The method of some embodiments synchronizes NAT records of long-term data flows more frequently than those of short-term flows. Multiple data flows pass between a device at an internal source address and a device at an external destination address through the active NAT gateway. For each flow, the method generates a NAT record. The method then determines whether the data flow is a short-term flow or a long-term flow and synchronizes the NAT records of the long-term flows, but not the NAT records of the short-term flows, with the standby gateway. The method of some embodiments synchronizing NAT records more frequently when NAT records are being generated quickly relative to prior generation rates and less frequently when NAT records are being generated slowly relative to the prior generation rates.

Abstract: Some embodiments provide a novel method for performing network address translation to share a limited number of external source network addresses among a large number of connections. Instead of allocating an external source network address for an egressing packet just based on its internal source network address, the method of some embodiments allocates the external source network address based on the egressing packet's source network address and destination network address. This allows a limited number of external source network addresses to be re-used for different destination network address. For instance, in some embodiments, the method's network address allocation scheme allows the same 64K (e.g., 2{circumflex over (?)}16) external source ports to be used for 64K connections for each destination network address.

Abstract: Some embodiments provide a novel method for performing network address translation to share a limited number of external source network addresses among a large number of connections. Instead of allocating an external source network address for an egressing packet just based on its internal source network address, the method of some embodiments allocates the external source network address based on the egressing packet's source network address and destination network address. This allows a limited number of external source network addresses to be re-used for different destination network address. For instance, in some embodiments, the method's network address allocation scheme allows the same 64K (e.g., 2{circumflex over (?)}16) external source ports to be used for 64K connections for each destination network address.

Abstract: Some embodiments provide a novel method for performing network address translation to share a limited number of external source network addresses among a large number of connections. Instead of allocating an external source network address for an egressing packet just based on its internal source network address, the method of some embodiments allocates the external source network address based on the egressing packet's source network address and destination network address. This allows a limited number of external source network addresses to be re-used for different destination network address. For instance, in some embodiments, the method's network address allocation scheme allows the same 64K (e.g., 2{circumflex over (?)}16) external source ports to be used for 64K connections for each destination network address.

Abstract: Described herein are systems, methods, and software to dynamically set a keepalive status for a client-server connection. In one implementation, a load balancer, providing load balancing operations for a plurality of servers, identifies a first FIN packet from a client to a server of the plurality of servers and sets a Transmission Control Protocol (TCP) keepalive status in association the connection between the client and the load balancer. The proxy further identifies a second FIN packet from the server to the client and removes the TCP keepalive status in association with the connection in response to the second FIN packet.

Abstract: The method of some embodiments synchronizes NAT records between an active gateway and a standby gateway. The active gateway encodes a NAT record that includes at least an external source IP address. The encoded NAT record does not include the external source IP address but does include an identifier that uniquely specifies the external source IP address. The active gateway sends the encoded NAT record to the standby gateway.