Arrangements for constructing a virtual private network (VPN) using forwarding techniques
First Claim
1. A forwarding apparatus including multiple VPN routing and forwarding tables (VRFs) configured to individually have routing tables provided for respective virtual private networks (VPNs),wherein each of the routing tables is structured to record a communication route of a packet based on a layer 3 address specifying an address of the packet and a forwarding destination layer 3 address specifying a forwarding destination of the packet from an assigned VRF or a VRF assigned to the routing table, as well as an extranet communication route of forwarding the packet from the assigned VRF to another VRF,the forwarding apparatus comprising:
- a first storage module configured to store a layer 2-layer 3-integrated forwarding table structured to record at least one entry, wherein each entry includes VRF information and a packet destination layer 3 address as search conditions for specifying the forwarding destination of the packet, as well as a forwarding destination layer 3 interface, a forwarding destination layer 3 address, and a forwarding destination layer 2 address as search results, when a correspondence relation of the forwarding destination layer 3 address to the forwarding destination layer 2 address is unresolved for an entry, the entry including specific data representing an ‘
unresolved’
state of the forwarding destination layer 2 address;
a route introducer configured to introduce each communication route, which is recorded in each of the routing tables, into the layer 2-layer 3-integrated forwarding table;
an address resolving module configured to introduce a correspondence relation of a layer 3 address to a layer 2 address of an adjacent device as an adjacent device layer 3 address-to-layer 2 address correspondence relation with regard to the forwarding destination layer 3 interface of an entry recorded in the layer 2-layer 3-integrated forwarding table, into the layer 2-layer 3-integrated forwarding table; and
a forwarding destination identification module configured to search the layer 2-layer 3-integrated forwarding table with a layer 3 address specifying an address recorded in the packet as a search key to specify the forwarding destination of the packet,in response to presence of an entry, which includes a direct route using a packet destination layer 3 address as the forwarding destination layer 3 address and the VRF information as the search condition for specifying the forwarding destination of the packet that is different from a VRF assigned to the forwarding destination layer 3 interface, in the layer 2-layer 3-integrated forwarding table, the address resolving module utilizing VRF information identical with the VRF information as the search condition to introduce the adjacent device layer 3 address-to-layer 2 address correspondence relation into the layer 2-layer 3-integrated forwarding table;
a second storage module configured to store a direct route VRF table that is structured to record at least one entry, wherein each entry includes a correspondence relation of a layer 3 interface and a layer 3 address to a VRF identifier group,wherein the address resolving module searches the direct route VRF table with a layer 3 interface connected to the adjacent device and the layer 3 address of the adjacent device as search keys to obtain a VRF identifier group and uses each VRF identifier of the obtained VRF identifier group for the VRF information as the search condition of specifying the forwarding destination of the packet to introduce the adjacent device layer 3 address-to-layer 2 address correspondence relation into the layer 2-layer 3-integrated forwarding table.
1 Assignment
0 Petitions
Accused Products
Abstract
An extranet direct route allowing extranet forwarding to a directly linked device is written in a layer 2-layer 3-integrated forwarding table. The procedure of introducing a layer 3 address-to-layer 2 address correspondence relation table entry into the layer 2-layer 3-integrated forwarding table searches the layer 2-layer 3-integrated forwarding table with a layer 3 address of the correspondence relation table entry and a layer 3 interface as search keys to retrieve any forwarding entry relating to an extranet direct route as a forwarding destination. The procedure subsequently extracts a VRF of each retrieved forwarding entry and introduces the correspondence relation table entry for the extracted VRF into the layer 2-layer 3-integrated forwarding table.
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Citations
16 Claims
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1. A forwarding apparatus including multiple VPN routing and forwarding tables (VRFs) configured to individually have routing tables provided for respective virtual private networks (VPNs),
wherein each of the routing tables is structured to record a communication route of a packet based on a layer 3 address specifying an address of the packet and a forwarding destination layer 3 address specifying a forwarding destination of the packet from an assigned VRF or a VRF assigned to the routing table, as well as an extranet communication route of forwarding the packet from the assigned VRF to another VRF, the forwarding apparatus comprising: -
a first storage module configured to store a layer 2-layer 3-integrated forwarding table structured to record at least one entry, wherein each entry includes VRF information and a packet destination layer 3 address as search conditions for specifying the forwarding destination of the packet, as well as a forwarding destination layer 3 interface, a forwarding destination layer 3 address, and a forwarding destination layer 2 address as search results, when a correspondence relation of the forwarding destination layer 3 address to the forwarding destination layer 2 address is unresolved for an entry, the entry including specific data representing an ‘
unresolved’
state of the forwarding destination layer 2 address;a route introducer configured to introduce each communication route, which is recorded in each of the routing tables, into the layer 2-layer 3-integrated forwarding table; an address resolving module configured to introduce a correspondence relation of a layer 3 address to a layer 2 address of an adjacent device as an adjacent device layer 3 address-to-layer 2 address correspondence relation with regard to the forwarding destination layer 3 interface of an entry recorded in the layer 2-layer 3-integrated forwarding table, into the layer 2-layer 3-integrated forwarding table; and a forwarding destination identification module configured to search the layer 2-layer 3-integrated forwarding table with a layer 3 address specifying an address recorded in the packet as a search key to specify the forwarding destination of the packet, in response to presence of an entry, which includes a direct route using a packet destination layer 3 address as the forwarding destination layer 3 address and the VRF information as the search condition for specifying the forwarding destination of the packet that is different from a VRF assigned to the forwarding destination layer 3 interface, in the layer 2-layer 3-integrated forwarding table, the address resolving module utilizing VRF information identical with the VRF information as the search condition to introduce the adjacent device layer 3 address-to-layer 2 address correspondence relation into the layer 2-layer 3-integrated forwarding table; a second storage module configured to store a direct route VRF table that is structured to record at least one entry, wherein each entry includes a correspondence relation of a layer 3 interface and a layer 3 address to a VRF identifier group, wherein the address resolving module searches the direct route VRF table with a layer 3 interface connected to the adjacent device and the layer 3 address of the adjacent device as search keys to obtain a VRF identifier group and uses each VRF identifier of the obtained VRF identifier group for the VRF information as the search condition of specifying the forwarding destination of the packet to introduce the adjacent device layer 3 address-to-layer 2 address correspondence relation into the layer 2-layer 3-integrated forwarding table. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A forwarding apparatus including multiple VPN routing and forwarding tables (VRFs) configured to individually have routing tables provided for respective virtual private networks (VPNs),
wherein each of the routing tables is structured to record a communication route of a packet based on a layer 3 address specifying an address of the packet and a forwarding destination layer 3 address specifying a forwarding destination of the packet from an assigned VRF or a VRF assigned to the routing table, as well as an extranet communication route of forwarding the packet from the assigned VRF to another VRF, the forwarding apparatus comprising: -
a first storage module configured to store a layer 2-layer 3-integrated forwarding table structured to record at least one entry, wherein each entry includes VRF information and a packet destination layer 3 address as search conditions for specifying the forwarding destination of the packet, as well as a forwarding destination layer 3 interface, a forwarding destination layer 3 address, and a forwarding destination layer 2 address as search results, when a correspondence relation of the forwarding destination layer 3 address to the forwarding destination layer 2 address is unresolved for an entry, the entry including specific data representing an ‘
unresolved’
state of the forwarding destination layer 2 address;a route introducer configured to introduce each communication route, which is recorded in each of the routing tables, into the layer 2-layer 3-integrated forwarding table; an address resolving module configured to introduce a correspondence relation of a layer 3 address to a layer 2 address of an adjacent device as an adjacent device layer 3 address-to-layer 2 address correspondence relation with regard to the forwarding destination layer 3 interface of an entry recorded in the layer 2-layer 3-integrated forwarding table, into the layer 2-layer 3-integrated forwarding table; and a forwarding destination identification module configured to search the layer 2-layer 3-integrated forwarding table with a layer 3 address specifying an address recorded in the packet as a search key to specify the forwarding destination of the packet, in response to presence of an entry, which includes a direct route using a packet destination layer 3 address as the forwarding destination layer 3 address and the VRF information as the search condition for specifying the forwarding destination of the packet that is different from a VRF assigned to the forwarding destination layer 3 interface, in the layer 2-layer 3-integrated forwarding table, the address resolving module utilizing VRF information identical with the VRF information as the search condition to introduce the adjacent device layer 3 address-to-layer 2 address correspondence relation into the layer 2-layer 3-integrated forwarding table; a determination module configured to, upon specification of an ‘
unresolved’
forwarding destination layer 2 address as a result of the search in the layer 2-layer 3-integrated forwarding table by the forwarding destination identification module, determine whether a corresponding entry as the result of the search is related to the direct route using the packet destination layer 3 address as the forwarding destination layer 3 address and whether a VRF as the search condition for specifying the forwarding destination of the packet is different from the VRF assigned to the forwarding destination layer 3 interface;a retrieval module configured to, in response to an affirmative determination by the determination module, search the layer 2-layer 3-integrated forwarding table with a forwarding destination layer 3 interface and a packet destination layer 3 address of the corresponding entry with the affirmative determination as search keys to retrieve a condition-satisfying adjacent device layer 3 address-to-layer 2 address correspondence relation; and a first introduction module configured to, when the condition-satisfying adjacent device layer 3 address-to-layer 2 address correspondence relation retrieved by the retrieval module has already been learnt, use a packet-receiving VRF for the VRF information as the search condition for specifying the forwarding destination of the packet to introduce the learnt adjacent device layer 3 address-to-layer 2 address correspondence relation into the layer 2-layer 3-integrated forwarding table. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A forwarding method effected in a forwarding apparatus including multiple VPN routing and forwarding tables (VRFs) configured to individually have routing tables provided for respective virtual private networks (VPNs), the forwarding method comprising
structuring each of the routing tables to record a communication route of a packet based on a layer 3 address specifying an address of the packet and a forwarding destination layer 3 address specifying a forwarding destination of the packet from an assigned VRF or a VRF assigned to the routing table, as well as an extranet communication route of forwarding the packet from the assigned VRF to another VRF, storing a layer 2-layer 3-integrated forwarding table structured to record at least one entry, wherein each entry includes VRF information and a packet destination layer 3 address as search conditions for specifying the forwarding destination of the packet, as well as a forwarding destination layer 3 interface, a forwarding destination layer 3 address, and a forwarding destination layer 2 address as search results, when a correspondence relation of the forwarding destination layer 3 address to the forwarding destination layer 2 address is unresolved for an entry, the entry including specific data representing an ‘ - unresolved’
state of the forwarding destination layer 2 address;introducing, via a route introducer, each communication route, which is recorded in each of the routing tables, into the layer 2-layer 3-integrated forwarding table; introducing, via an address resolving module, a correspondence relation of a layer 3 address to a layer 2 address of an adjacent device as an adjacent device layer 3 address-to-layer 2 address correspondence relation with regard to the forwarding destination layer 3 interface of an entry recorded in the layer 2-layer 3-integrated forwarding table, into the layer 2-layer 3-integrated forwarding table; and searching, via a forwarding destination identification module, the layer 2-layer 3-integrated forwarding table with a layer 3 address specifying an address recorded in the packet as a search key to specify the forwarding destination of the packet, in response to presence of an entry, which includes a direct route using a packet destination layer 3 address as the forwarding destination layer 3 address and the VRF information as the search condition for specifying the forwarding destination of the packet that is different from a VRF assigned to the forwarding destination layer 3 interface, in the layer 2-layer 3-integrated forwarding table, the address resolving module utilizing VRF information identical with the VRF information as the search condition to introduce the adjacent device layer 3 address-to-layer 2 address correspondence relation into the layer 2-layer 3-integrated forwarding table; storing, via a second storage module, a direct route VRF table that is structured to record at least one entry, wherein each entry includes a correspondence relation of a layer 3 interface and a layer 3 address to a VRF identifier group, wherein the address resolving module searches the direct route VRF table with a layer 3 interface connected to the adjacent device and the layer 3 address of the adjacent device as search keys to obtain a VRF identifier group and uses each VRF identifier of the obtained VRF identifier group for the VRF information as the search condition of specifying the forwarding destination of the packet to introduce the adjacent device layer 3 address-to-layer 2 address correspondence relation into the layer 2-layer 3-integrated forwarding table.
- unresolved’
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16. A forwarding method effected in a forwarding apparatus including multiple VPN routing and forwarding tables (VRFs) configured to individually have routing tables provided for respective virtual private networks (VPNs), the forwarding method comprising
structuring each of the routing tables to record a communication route of a packet based on a layer 3 address specifying an address of the packet and a forwarding destination layer 3 address specifying a forwarding destination of the packet from an assigned VRF or a VRF assigned to the routing table, as well as an extranet communication route of forwarding the packet from the assigned VRF to another VRF, storing a layer 2-layer 3-integrated forwarding table structured to record at least one entry, wherein each entry includes VRF information and a packet destination layer 3 address as search conditions for specifying the forwarding destination of the packet, as well as a forwarding destination layer 3 interface, a forwarding destination layer 3 address, and a forwarding destination layer 2 address as search results, when a correspondence relation of the forwarding destination layer 3 address to the forwarding destination layer 2 address is unresolved for an entry, the entry including specific data representing an ‘ - unresolved’
state of the forwarding destination layer 2 address;introducing, via a route introducer, each communication route, which is recorded in each of the routing tables, into the layer 2-layer 3-integrated forwarding table; introducing, via an address resolving module, a correspondence relation of a layer 3 address to a layer 2 address of an adjacent device as an adjacent device layer 3 address-to-layer 2 address correspondence relation with regard to the forwarding destination layer 3 interface of an entry recorded in the layer 2-layer 3-integrated forwarding table, into the layer 2-layer 3-integrated forwarding table; and searching, via a forwarding destination identification module, the layer 2-layer 3-integrated forwarding table with a layer 3 address specifying an address recorded in the packet as a search key to specify the forwarding destination of the packet, in response to presence of an entry, which includes a direct route using a packet destination layer 3 address as the forwarding destination layer 3 address and the VRF information as the search condition for specifying the forwarding destination of the packet that is different from a VRF assigned to the forwarding destination layer 3 interface, in the layer 2-layer 3-integrated forwarding table, the address resolving module utilizing VRF information identical with the VRF information as the search condition to introduce the adjacent device layer 3 address-to-layer 2 address correspondence relation into the layer 2-layer 3-integrated forwarding table; determining, via a determination module, upon specification of an ‘
unresolved’
forwarding destination layer 2 address as a result of the search in the layer 2-layer 3-integrated forwarding table by the forwarding destination identification module, whether a corresponding entry as the result of the search is related to the direct route using the packet destination layer 3 address as the forwarding destination layer 3 address and whether a VRF as the search condition for specifying the forwarding destination of the packet is different from the VRF assigned to the forwarding destination layer 3 interface;searching, via a retrieval module, in response to an affirmative determination by the determination module, the layer 2-layer 3-integrated forwarding table with a forwarding destination layer 3 interface and a packet destination layer 3 address of the corresponding entry with the affirmative determination as search keys to retrieve a condition-satisfying adjacent device layer 3 address-to-layer 2 address correspondence relation; and using, when the condition-satisfying device layer 3 address-to-layer 2 address correspondence relation retrieved by the retrieval module has already been learnt, a packet-receiving VRF for the VRF information as the search condition for specifying the forwarding destination of the packet to introduce the learnt adjacent device layer 3 address-to-layer 2 address correspondence relation into the layer 2-layer 3-integrated forwarding table.
- unresolved’
Specification