Abstract: Redundant gateway methods, apparatus and systems using more than one gateway device in a gateway device group for communications directed outside of a LAN. Failover services are thus provided in the event that an active router or other gateway device fails. Network address translation (NAT) services are provided simultaneously by having all gateway devices in the redundancy group create and maintain IP aliases and static NAT mappings, while disabling all gateway devices operating in a non-active mode from replying to address resolution protocol requests from hosts. A gateway device may be configured to operate in a redundancy group in an active operating mode or a non-active operating mode. The gateway device handles transmissions into and out of the network to which it is connected only when the gateway device is in the active operating mode so as to avoid system corruption due to ARP activity and message transmissions by non-active gateway devices.

Abstract: Methods and apparatus for processing a DNS query by a NAT device are disclosed. A NAT device (e.g., NAT-PT device) receives the DNS query from a node. The NAT device then sends two DNS queries to a DNS server. Specifically, each of the DNS queries requests an IP address in a different version of IP (e.g., IPv4 or IPv6). For example, each of the DNS queries may request an A record or an AAAA record. When the NAT device receives two DNS replies from the DNS server, it forwards only one of the DNS replies to the node. Specifically, the DNS reply that is forwarded includes at least one answer record. DNS replies that do not include at least one answer record, or are received subsequent to forwarding the DNS reply to the node, are dropped by the NAT device.

Abstract: Gateway and NAT services to a single host or large number of hosts on a local network using a redundancy group having gateway devices. A pool of unique IP addresses are partitioned into address blocks, one of which is assigned to a gateway device. Using the unique IP addresses in its assigned address block, the gateway device translates local IP addresses of hosts on a local network to unique IP addresses from the gateway device's assigned address block for host packets destined for outside networks and creates a mapping of the translation. The gateway device notifies other gateway devices in the redundancy group of the mapping. A master mapping database or a local mapping database is updated whenever one of the gateway devices performs a translation.

Abstract: Disclosed are methods and apparatus for reliably handling Stream Control Transmission Protocol (SCTP) multi-homed connections across multiple translation (e.g., NAT devices), such that messages sent between endpoints, which include one or more multi-homed devices, reach their intended destination. In one embodiment, a method for handling SCTP multi-homed connections across multiple translation devices is disclosed. When an SCTP association between two hosts is being established through a particular translation device, multi-homing information for one or both of the hosts is communicated from the particular translation device to one or more other translation devices which are associated with the particular translation device.

Abstract: Methods and apparatuses for distributing network address translation. By having a gateway inform inside devices of global addresses, the gateway can avoid performing many functions of a traditional NAT box. Specifically, an inside device is informed of a global address shared by all devices on the inside device's network segment. Each device on that segment would be assigned a range of ports to distinguish messages from separate devices that use the same global address.

Abstract: Methods and apparatuses for distributing network address translation. By having a gateway inform inside devices of global addresses, the gateway can avoid performing many functions of a traditional NAT box. Specifically, an inside device is informed of a global address shared by all devices on the inside device's network segment. Each device on that segment would be assigned a range of ports to distinguish messages from separate devices that use the same global address.

Abstract: Disclosed are methods and apparatus for efficiently and reliably handling DNS (domain name service) PTR (pointer) queries and replies across IPv4 and IPv6 networks. In general terms, an IPv4 DNS PTR query which is sent by an IPv4 device to an IPv6 DNS Server is intercepted or received, for example, by a network device configured with NAT-PT and DNS-ALG. The received IPv4 DNS PTR query is then translated into two different types of IPv6 DNS PTR queries: a query having an “IP6.INT” string and a query having an “IP6.ARPA” string. Both types of IPv6 queries are then sent to the IPv6 destination DNS Server. Whether the DNS sends an IP6.ARPA or an IP6.INT type reply or both types of replies back, a valid reply is identified (if present) and then translated before reaching the IPv4 device.

Abstract: Disclosed are methods and apparatus for reliably handling Stream Control Transmission Protocol (SCTP) multi-homed connections across multiple translation (e.g., NAT devices), such that messages sent between endpoints, which include one or more multi-homed devices, reach their intended destination. In one embodiment, a method for handling SCTP multi-homed connections across multiple translation devices is disclosed. When an SCTP association between two hosts is being established through a particular translation device, multi-homing information for one or both of the hosts is communicated from the particular translation device to one or more other translation devices which are associated with the particular translation device.

Abstract: Disclosed are methods and apparatus for efficiently and reliably handling DNS (domain name service) PTR (pointer) queries and replies across IPv4 and IPv6 networks. In general terms, an IPv4 DNS PTR query which is sent by an IPv4 device to an IPv6 DNS Server is intercepted or received, for example, by a network device configured with NAT-PT and DNS-ALG. The received IPv4 DNS PTR query is then translated into two different types of IPv6 DNS PTR queries: a query having an “IP6.INT” string and a query having an “IP6.ARPA” string. Both types of IPv6 queries are then sent to the IPv6 destination DNS Server. Whether the DNS sends an IP6.ARPA or an IP6.INT type reply or both types of replies back, a valid reply is identified (if present) and then translated before reaching the IPv4 device.

Abstract: Gateway and NAT services to a single host or large number of hosts on a local network using a redundancy group having gateway devices. A pool of unique IP addresses are partitioned into address blocks, one of which is assigned to a gateway device. Using the unique IP addresses in its assigned address block, the gateway device translates local IP addresses of hosts on a local network to unique IP addresses from the gateway device's assigned address block for host packets destined for outside networks and creates a mapping of the translation. The gateway device notifies other gateway devices in the redundancy group of the mapping. A master mapping database or a local mapping database is updated whenever one of the gateway devices performs a translation.