Abstract: A system and method for intelligently detecting a duplicate address attack is described. The system and method comprise transferring a first address conflict check message; receiving a first address conflict check response message; performing intelligent Duplicate Address Detection (DAD) to determine if the duplicate address attack is valid; and if the duplicate address attack is valid, then reporting the duplicate address attack to a monitoring server. An intelligent switch that detects the DAD attack blocks further address conflict check response messages from the attacker's MAC address.

Abstract: Systems and methods include determining if a destination address for a destination host is on-link; when the destination address is on-link, negotiating and selecting a Link-Local (LL) source address and a LL destination address that is on-link; and, when the destination address is not on-link, utilizing an address for the destination host separate from LL addresses. The destination host can be a multi-homed host. The negotiating and selecting and the utilizing are based on a plurality of rules performed in order. The plurality of rules are defined in RFC 6724, September 2012.

Abstract: Systems and methods include determining if a destination address for a destination host is on-link; when the destination address is on-link, negotiating and selecting a Link-Local (LL) source address and a LL destination address that is on-link; and, when the destination address is not on-link, utilizing an address for the destination host separate from LL addresses. The destination host can be a multi-homed host. The negotiating and selecting and the utilizing are based on a plurality of rules performed in order. The plurality of rules are defined in RFC 6724, September 2012.

Abstract: Systems, methods, software and apparatus to enhance connectivity to an IPv6-only SIP client and an IPv4-only server and/or client. In one embodiment, a method comprises assigning the IPv6-only client an IPv4-translatable IPv6 Internet Protocol (IP) address. The method further includes determining the IPv6-only client is initiating the SIP communication session with the IPv4-only server or client. The method further includes extracting an IPv4 IP address from the IPv4 translatable IPv6 IP address, and using the extracted IPv4 address in a SIP contact header to register with an IPv4 SIP server and the Via header to get 200 OK responses. The IPv4 address used in the ‘c’ or ‘m’ lines is used to synthesize an IPv4 translatable IPv6 address for directly transferring media between an IPv6-only client and an IPv4-only client.

Abstract: A method, system, device, or apparatus for selecting an IP address for a message. The method, system, device, or apparatus is used when there are two or more IP addresses for a multihomed device. The method determines an IP address reachable from a destination for the message. The message is generated using the reachable IP address as the hostname of the multihomed device. The generated message is transferred to the destination.

Abstract: A system and method for intelligently detecting a duplicate address attack is described. The system and method comprise transferring a first address conflict check message; receiving a first address conflict check response message; performing intelligent Duplicate Address Detection (DAD) to determine if the duplicate address attack is valid; and if the duplicate address attack is valid, then reporting the duplicate address attack to a monitoring server. An intelligent switch that detects the DAD attack blocks further address conflict check response messages from the attacker's MAC address.

Abstract: A method of engineering media path selection is described. Addresses and media paths are selected using a media path selection policy. Additionally, a candidate address list may be considered. Using the media path selection policy, devices may select the first hop egress router and a remote default router for transferring data.

Abstract: A method, system, device, or apparatus for selecting an IP address for a message. The method, system, device, or apparatus is used when there are two or more IP addresses for a multihomed device. The method determines an IP address reachable from a destination for the message. The message is generated using the reachable IP address as the hostname of the multihomed device. The generated message is transferred to the destination.

Abstract: A method of updating/reordering the priority of a remote candidate list based on an early determination of connectivity. In one embodiment, the method of system comprises performing connectivity checks for routing table entries early and generating a reachable list. In another embodiment, the method and systems prioritize the remote candidate list based on a reachable list. When a session request is received, the remote candidate list can be compared to the reachable list and addresses in the remote candidate list with prefixes that match prefixes in the reachable list are given the highest priority. The enhanced connectivity provides for a better user experience and avoids initial delays between initial signaling and the start of media flow.

Abstract: A method of engineering media path selection is described. Addresses and media paths are selected using a media path selection policy. Additionally, a candidate address list may be considered. Using the media path selection policy, devices may select the first hop egress router and a remote default router for transferring data.

Abstract: Examples disclosed herein provide methods and systems for selecting Internet Protocol addresses for Session Initiation Protocol (SIP) communications. In at least one implementation, a method of operating a communication network utilizing a session initiation protocol (SIP) is provided. The method performed within a second communication device includes receiving a SIP invite from a first communication device, and determining a source IP address for the second communication device, using an IP address for a third communication device as a destination address within a source address selection algorithm (SASA) function. The method further includes adding a Via header within the SIP invite to include the SASA determined source IP address for the second communication device, adding a Record-Route header within the SIP invite to include the SASA determined source IP address for the second communication device, and transferring the modified SIP invite to the third communication device.

Abstract: Systems, methods, software and apparatus to enhance connectivity to nodes in a single-mode network environment. An ordered list of IP address is generated based on configuration order rules, and each IP address is probed to determine reachability.

Abstract: Embodiments disclosed herein provide systems, methods, and computer readable media for extending the lifetime of a network address when an address system is unavailable. In a particular embodiment, a method provides, upon determining that a first network address for a network element has reached a preferred lifetime for the first network address, transitioning the network element to an extended rebind state that allows the first network address to remain in the preferred state. While the network element is in the extended rebind state, the method provides attempting to contact an address system and determining whether a second network element is assigned the first network address. The method further provides maintaining the first network address in the preferred state and the network element in the extended rebind state until contact is made with the address system or the second network element is determined to be assigned the first network address.

Abstract: Examples disclosed herein provide methods and systems for selecting Internet Protocol addresses for Session Initiation Protocol (SIP) communications. In at least one implementation, a method of operating a communication network utilizing a session initiation protocol (SIP) is provided. The method performed within a second communication device includes receiving a SIP invite from a first communication device, and determining a source IP address for the second communication device, using an IP address for a third communication device as a destination address within a source address selection algorithm (SASA) function. The method further includes adding a Via header within the SIP invite to include the SASA determined source IP address for the second communication device, adding a Record-Route header within the SIP invite to include the SASA determined source IP address for the second communication device, and transferring the modified SIP invite to the third communication device.

Abstract: Examples disclosed herein provide methods and systems for selecting Internet Protocol addresses for Session Initiation Protocol (SIP) communications. In at least one implementation, a method of operating a first communication device includes applying a source address selection algorithm to determine at least one source Internet Protocol (IP) address for the first communication device, and transferring a communication invite that indicates the at least one source IP address. The method further provides, receiving, from a second communication device, a response to the invite that indicates at least one IP address for the second communication device, applying SASA to the at least one IP address to determine a third source IP address for the first communication device, and initiating a communication with the second communication device using the third source IP address.

Abstract: Examples disclosed herein provide methods and systems for selecting Internet Protocol addresses for Session Initiation Protocol (SIP) communications. In at least one implementation, a method of operating a first communication device includes applying a source address selection algorithm to determine at least one source Internet Protocol (IP) address for the first communication device, and transferring a communication invite that indicates the at least one source IP address. The method further provides, receiving, from a second communication device, a response to the invite that indicates at least one IP address for the second communication device, applying SASA to the at least one IP address to determine a third source IP address for the first communication device, and initiating a communication with the second communication device using the third source IP address.

Abstract: Embodiments disclosed herein provide systems, methods, and computer readable media for extending the lifetime of a network address when an address system is unavailable. In a particular embodiment, a method provides, upon determining that a first network address for a network element has reached a preferred lifetime for the first network address, transitioning the network element to an extended rebind state that allows the first network address to remain in the preferred state. While the network element is in the extended rebind state, the method provides attempting to contact an address system and determining whether a second network element is assigned the first network address. The method further provides maintaining the first network address in the preferred state and the network element in the extended rebind state until contact is made with the address system or the second network element is determined to be assigned the first network address.