# US 2014/0192808 A1 · Tunnel sub-interface using ip header field > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0192808 A1 - Document ID: US20140192808A1 - Status: Published application - Kind: A1 - Application number: 13/737,641 - Filed: 2013-01-09 - Published: 2014-07-10 - Earliest claimed: 2013-01-09 - Assignees: Cisco Technology, Inc. - Applicants: Cisco Technology, Inc. - Inventors: Pascal Thubert; Michael Behringer; Aswini Kumar Sattaluri - Web page: https://patentgrep.com/patent/US20140192808A1 ## CPC - H04L 45/74: Address processing for routing - H04L 12/4633: {Interconnection of networks using encapsulation techniques, e.g. tunneling} - H04L 45/64: using an overlay routing layer - H04L 45/68: {Pseudowire emulation, e.g. IETF WG PWE3} - H04L 63/164: {at the network layer} - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract In one implementation, sub-interfaces are defined in Layer three (L3) tunnels, such as generic routing encapsulization (GRE) or Internet protocol security (IPsec) tunnels. Sub-interfaces inside a L3 tunnel may be preferred to using several L3 tunnels. The flow label of the tunnel header is used to define sub-interfaces of a tunnel interface. The flow label is populated with a routing instance identifier to index the sub-interfaces. ## Claims ### Claim 1 A method comprising: creating tunnels between devices in a network; operating multiple routing instances for the network; inserting identifiers of the routing instances for packets of data traffic into flow label fields of the tunnels; communicating the packets of the data traffic between the devices with the tunnels; separating the packets of the data traffic based on the identifiers of the routing instances; and routing the separated packets according to the respective routing instances from the flow label fields. ### Claim 2 (depends on 1) The method of claim 1 wherein creating the tunnels comprises creating secure tunnels. ### Claim 3 (depends on 1) The method of claim 1 wherein creating the tunnels comprises creating the tunnels as IPsec tunnels. ### Claim 4 (depends on 1) The method of claim 1 wherein creating the tunnels comprises creating virtual point-to-point tunnels at layer three ### Claim 5 (depends on 1) The method of claim 1 wherein operating the multiple routing instances for the network comprises operating multiple routing instances of a routing protocol for low power and lossy networks (RPL), and wherein inserting comprises inserting RPL instance identifiers. ### Claim 6 (depends on 1) The method of claim 1 wherein operating the multiple routing instances comprises operating a control plane with different ones of the instances corresponding to network evolution over time in an autonomic network. ### Claim 7 (depends on 1) The method of claim 1 wherein operating the multiple routing instances comprises operating the multiple routing instances pursuant to a common virtual routing and forwarding. ### Claim 8 (depends on 1) The method of claim 1 wherein inserting the identifiers comprises inserting the identifiers of the routing instances into differentiated services code point fields. ### Claim 9 (depends on 1) The method of claim 1 wherein inserting the identifiers comprises inserting the identifiers into a tunnel header. ### Claim 10 (depends on 1) The method of claim 1 wherein inserting, communicating, and separating comprise establishing sub-interfaces in the tunnels without creating any parallel tunnels. ### Claim 11 (depends on 1) The method of claim 1 wherein communicating comprises adding tunnel headers including the flow label fields with the identifiers to the packets and transmitting pursuant to the tunnel headers. ### Claim 12 (depends on 1) The method of claim 1 wherein separating comprises extracting the identifiers from the flow label fields of tunnel headers, and wherein routing comprises removing the tunnel headers and transmitting the packets based on destinations in the packets. ### Claim 13 (depends on 1) The method of claim 1 further comprising including the flow label fields in message integrity checks. ### Claim 14 (depends on 1) The method of claim 1 wherein the flow label fields are of tunnel headers, further comprising swapping a flow label field of the packets with the flow label fields of the tunnel headers for the communicating, wherein the communicating comprises encrypting the packets. ### Claim 15 Logic encoded in one or more non-transitory computer-readable media that includes code for execution and when executed by a processor is operable to perform operations comprising: assigning a sub-interface of an interface of an Internet protocol (IP) tunnel at layer three with a flow label or differentiated services field of the interface of the IP tunnel; and transmitting traffic for the sub-interface over the IP tunnel. ### Claim 16 (depends on 15) The logic of claim 15 further comprising associating the sub-interface with an instance of a routing protocol, other sub-interfaces of the IP tunnel assigned for other instances of the same routing protocol. ### Claim 17 (depends on 15) The logic of claim 15 wherein assigning comprises assigning by an autonomic router for a control plane in an autonomic network. ### Claim 18 (depends on 15) The logic of claim 15 where assigning comprises indexing virtual routing and forwarding with the interface for the IP tunnel and the flow label or differentiated services field. ### Claim 19 (depends on 15) The logic of claim 15 further comprising protecting against modifications to the transmitted traffic by incorporating the flow label or differentiated services field into a packet signature, swapping a flow label or differentiated services field of the traffic with the flow label or differentiated services field of the interface prior to transmitting, or both incorporating and swapping. ### Claim 20 An apparatus comprising: a memory operable to store identifiers for different routing protocol instances of a same virtual routing and forwarding and to store a tunnel header for a tunnel interface; and a processor configured to tag sub-interfaces of the tunnel interface with the identifiers positioned in a flow label or a differentiated services field of the tunnel header. ### Claim 21 (depends on 20) The apparatus of claim 20 wherein the virtual routing and forwarding comprises a routing protocol for low power and lossy networks (RPL), the identifiers being for the different routing protocol instances of the RPL, the tunnel header comprising an IPsec tunnel, the identifiers positioned in the flow label of IPv6, and wherein the processor is configured to swap the flow label of the tunnel header with a flow label of a payload.