Abstract: IP Multinetting on a local area network is simulated by performing VLAN translation at a port connecting to the local area network. This allows IP addresses from multiple subnets to be associated with a single VLAN on the Local Area Network (LAN), while allowing the core switch to process the packets with a one-to-one correspondence between IP Subnet and VLAN. When a packet is received from the local area network at an IP multinetting port, the VLAN ID will be read to determine if the packet contains the IP Multinetting VLAN ID. The IP Subnet address will also be checked to see if the packet is associated with an IP Subnet that is part of the Multinetting. If so, the multinetting VLAN ID will be changed to an IP Subnet specific VLAN ID before the packet is processed by the core switch. In the reverse direction, IP subnet specific VLAN IDs will be translated to the IP Multinetting VLAN ID.

Abstract: Nodes on a link state protocol controlled Ethernet network implement a link state routing protocol such as IS-IS. Nodes assign an IP address or I-SID value per VRF and then advertise the IP addresses or I-SID values in IS-IS LSAs. When a packet is to be forwarded on the VPN, the ingress node identifies the VRF for the packet and performs an IP lookup in customer address space in the VRF to determine the next hop and the IP address or I-SID value of the VRF on the egress node. The ingress node prepends an I-SID or IP header to identify the VRFs and then creates a MAC header to allow the packet to be forwarded to the egress node on the link state protocol controlled Ethernet network. When the packet is received at the egress node, the MAC header is stripped from the packet and the appended I-SID or IP header is used to identify the egress VRF.

Abstract: Nodes on a link state protocol controlled Ethernet network implement a link state routing protocol such as IS-IS. Nodes assign an IP address or I-SID value per VRF and then advertise the IP addresses or I-SID values in IS-IS LSAs. When a packet is to be forwarded on the VPN, the ingress node identifies the VRF for the packet and performs an IP lookup in customer address space in the VRF to determine the next hop and the IP address or I-SID value of the VRF on the egress node. The ingress node prepends an I-SID or IP header to identify the VRFs and then creates a MAC header to allow the packet to be forwarded to the egress node on the link state protocol controlled Ethernet network. When the packet is received at the egress node, the MAC header is stripped from the packet and the appended I-SID or IP header is used to identify the egress VRF.

Abstract: MP-BGP VPN infrastructure based on IETF RFC 4364/2547 is used to configure a layer 2 VPN on an IP network. VRFs for the VPN are configured on Ethernet switches and service IP addresses are associated with each configured VRF. The service IP addresses are exchanged to enable VPN traffic to be encapsulated for transport over the IP network. To enable a L2 VPN to be established on the network, a VPN-VLAN ID will be configured for the L2 VPN and import/export route targets for the VPN-VLAN will be set in each VRF and UNI-VLAN that is part of the VPN. The VPN-VLAN will be announced to all PEs using MP-iBGP with export route targets set for this VPN-VLAN. The PE's control plane learns the VPN-VLAN on a logical port if the import RT matches the export RT received by the MP-iBGP control plane. Once the VPN-VLAN is learned on a logical port, the PE will perform MAC learning on that logical port and treat the logical port as if it were part of the L2 VLAN.

Abstract: IP Multinetting on a local area network is simulated by performing VLAN translation at a port connecting to the local area network. This allows IP addresses from multiple subnets to be associated with a single VLAN on the Local Area Network (LAN), while allowing the core switch to process the packets with a one-to-one correspondence between IP Subnet and VLAN. When a packet is received from the local area network at an IP multinetting port, the VLAN ID will be read to determine if the packet contains the IP Multinetting VLAN ID. The IP Subnet address will also be checked to see if the packet is associated with an IP Subnet that is part of the Multinetting. If so, the multinetting VLAN ID will be changed to an IP Subnet specific VLAN ID before the packet is processed by the core switch. In the reverse direction, IP subnet specific VLAN IDs will be translated to the IP Multinetting VLAN ID.

Abstract: Techniques for routing data between network area are disclosed, In one particular exemplary embodiment, the techniques may be realized as a method for routing data between layer 2 network areas of backbone bridges comprising the steps of receiving data at a network element containing an internally terminated Network to Network Interface (NNI) for a plurality of network areas, identifying a destination address associated with the data, determining a network area of the plurality of network areas associated with the data, and performing one or more data flow treatments associated with the data using the internally terminated Network to Network Interface (NNI).

Abstract: Multicast traffic may be routed using DVMRP or PIM over a Split MultiLink Trunk (SMLT). Network elements on the split side of the SMLT are interconnected by an Inter-Switch Trunk (IST) to enable them to exchange control messages associated with the multicast. When a control message is received on the IST, the network element will determine if the multicast control message is associated with a normal multicast or is associated with multicast over an SMLT link. Control messages related to SMLT links will be processed as if they were received over the SMLT link rather than the IST link. To prevent traffic from being forwarded by multiple network elements over the SMLT link, data traffic from an IST link may not be transmitted over an SMLT link. Flags are used to indicate whether a link is a SMLT link or regular link. Fast recovery may occur by causing participants to transmit triggered join messages upon recovery from a failure.

Abstract: In a communications network, a cluster switch is provided, where the cluster switch has plural individual switches. An abstraction layer is provided in the cluster switch, such that an interface having a set of ports is provided to upper layer logic in the cluster switch. The set of ports includes a collection of ports of the individual switches. Control traffic and data traffic are communicated over virtual tunnels between individual switches of the cluster switch, where each virtual tunnel has an active channel and at least one standby channel.

Abstract: Multicast traffic may be routed using DVMRP or PIM over a Split MultiLink Trunk (SMLT). Network elements on the split side of the SMLT are interconnected by an Inter-Switch Trunk (IST) to enable them to exchange control messages associated with the multicast. When a control message is received on the IST, the network element will determine if the multicast control message is associated with a normal multicast or is associated with multicast over an SMLT link. Control messages related to SMLT links will be processed as if they were received over the SMLT link rather than the IST link. To prevent traffic from being forwarded by multiple network elements over the SMLT link, data traffic from an IST link may not be transmitted over an SMLT link. Flags are used to indicate whether a link is a SMLT link or regular link. Fast recovery may occur by causing participants to transmit triggered join messages upon recovery from a failure.

Abstract: Nodes on a link state protocol controlled Ethernet network implement a link state routing protocol such as IS-IS. Nodes assign an IP address or I-SID value per VRF and then advertise the IP addresses or I-SID values in IS-IS LSAs. When a packet is to be forwarded on the VPN, the ingress node identifies the VRF for the packet and performs an IP lookup in customer address space in the VRF to determine the next hop and the IP address or I-SID value of the VRF on the egress node. The ingress node prepends an I-SID or IP header to identify the VRFs and then creates a MAC header to allow the packet to be forwarded to the egress node on the link state protocol controlled Ethernet network. When the packet is received at the egress node, the MAC header is stripped from the packet and the appended I-SID or IP header is used to identify the egress VRF.

Abstract: A new type of Provider Edge (PE) device is used to support BGP-based IP-VPNs. Each VRF instance in a PE device is associated with a dedicated IP address (Service IP address). Each service IP address is dedicated to a VRF in a PE device. The service IP address is distributed by BGP for VPN route association. Customer/VRF IP packets can be sent to a VRF instance in the egress PE device using service IP header encapsulation (with IP Destination Address=Service IP address of egress PE's VRF & IP Source Address=Service IP address of ingress PE's VRF). This obviates the need for explicit tunnels in the core.

Abstract: In a communications network, a cluster switch is provided, where the cluster switch has plural individual switches. An abstraction layer is provided in the cluster switch, such that an interface having a set of ports is provided to upper layer logic in the cluster switch. The set of ports includes a collection of ports of the individual switches. Control traffic and data traffic are communicated over virtual tunnels between individual switches of the cluster switch, where each virtual tunnel has an active channel and at least one standby channel.

Abstract: In one embodiment, the invention relates to a method in which at least two aggregation devices, which logically operate as a single device, are interconnected by an Inter Switch Trunk (IST) link. Thereafter, forwarding records of local routing instances between the at least two aggregation devices are synchronized to enable one aggregation device to support data traffic for the other aggregation device if it has failed or a link to the aggregation device has failed.

Abstract: A VLAN is implemented with a logical hub and spoke topology that obviates local switching. Member devices are connected to a hub device such as a router via intermediate devices such as Layer 2 switches that support individual IP subnets within the VLAN. The Layer 2 switch does not allow bridging, so there is no IP subnet broadcast domain. Further, the Layer 2 switch implements only a single logical broadcast uplink port which is connected to the router. The Layer 2 switch also implements only point-to-point downlink ports, i.e., to individual member devices. Consequently, all traffic is forced to flow through the router, e.g., broadcast traffic, multicast traffic and traffic of unknown destination received by the Layer 2 switch from a member device is only flooded to the router, and the router performs intra-subnet routing in addition to routing between subnets and between VLANs.

Abstract: A first node includes ports and a controller to receive a test packet at a first one of the ports. The first node determines whether the received test packet has a destination address that matches one or more predefined addresses associated with a second node. Presence of a loop in a communications network in which the first and second nodes are located is indicated in response to detecting receipt of the test packet containing the matching destination address.

Abstract: A multilink trunk from a client device in a communication network is split between two aggregation devices such that each aggregation device is connected to at least one link of the multilink trunk. The aggregation devices work in conjunction to appear to the client device as a single device connected to the client device over the multilink trunk. The aggregation devices transmit identical bridge protocol data units to the client device over their respective links of the multilink trunk. The aggregation devices exchange operational information and data packets over inter-device communication ports. A failure of the split multilink trunk at one aggregation device is restored through the other aggregation device.

Abstract: In one embodiment, the invention relates to a method in which at least two aggregation devices, which logically operate as a single device, are interconnected by an Inter Switch Trunk (IST) link. Thereafter, forwarding records of local routing instances between the at least two aggregation devices are synchronized to enable one aggregation device to support data traffic for the other aggregation device if it has failed or a link to the aggregation device has failed.

Abstract: A multilink trunk from a client device in a communication network is split between two aggregation devices such that each aggregation device is connected to at least one link of the multilink trunk. The aggregation devices work in conjunction to appear to the client device as a single device connected to the client device over the multilink trunk. The aggregation devices transmit identical bridge protocol data units to the client device over their respective links of the multilink trunk. The aggregation devices exchange operational information and data packets over inter-device communication ports. A failure of the split multilink trunk at one aggregation device is restored through the other aggregation device.