Forwarding Apparatus, Forwarding Method, and Computer Program Product
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.
1 Assignment
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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.
52 Citations
17 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. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A forwarding method of forwarding a packet between 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 the 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 method comprising the steps of: -
(a) providing a layer 2-layer 3-integrated forwarding table structured to record at least one entry and introducing each communication route, which is recorded in each of the routing tables, into the layer 2-layer 3-integrated forwarding table, wherein each entry of the layer 2-layer 3-integrated forwarding table 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, and 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 includes specific data representing an ‘
unresolved’
state of the forwarding destination layer 2 address;(b) introducing 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 (c) searching 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, the step (c) including the step of; (c-1) 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, 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.
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17. A computer program product configured to cause a computer to forward a packet between 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 the 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 computer program product comprising: -
a first program code of providing a layer 2-layer 3-integrated forwarding table structured to record at least one entry and introducing each communication route, which is recorded in each of the routing tables, into the layer 2-layer 3-integrated forwarding table, wherein each entry of the layer 2-layer 3-integrated forwarding table 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, and 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 includes specific data representing an ‘
unresolved’
state of the forwarding destination layer 2 address;a second program code of introducing a correspondence relation of a layer 3 address to a layer 2 address of an adjacent device as 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; a third program code of searching 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; and a computer readable medium configured to store the first through the third program codes, the third program code including; a program code of, 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, 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.
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Specification