Mce - HP 6125XLG Configuration Manual

Figure 2 VPN-IPv4 address structure
The MCE device does not support advertising VPN routes through MP-BGP. However, to run BGP VPN
instances on the MCE device, you must configure a unique RD for each VPN instance to distinguish
between the VPN instances.
An RD can be in one of the following formats distinguished by a 2-byte Type field:
When the value of the Type field is 0, the Administrator subfield occupies two bytes, the Assigned
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number subfield occupies four bytes, and the RD format is 16-bit AS number:32-bit user-defined
number. For example, 100:1.
When the value of the Type field is 1, the Administrator subfield occupies four bytes, the Assigned
•
number subfield occupies two bytes, and the RD format is 32-bit IPv4 address:16-bit user-defined
number. For example, 172.1.1.1:1.
When the value of the Type field is 2, the Administrator subfield occupies four bytes, the Assigned
•
number subfield occupies two bytes, and the RD format is 32-bit AS number:16-bit user-defined
number, where the minimum value of the AS number is 65536. For example, 65536:1.
To guarantee global uniqueness for an RD, do not set the Administrator subfield to any private AS
number or private IP address.
Route target attributes
MPLS L3VPN uses the BGP extended community attributes called route target attributes or route target
attributes, to control the advertisement of VPN routing information.
A VPN instance on a PE supports the following types of route target attributes:
Export target attribute—A PE sets the export attribute for VPN-IPv4 routes learned from directly
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connected sites before advertising them to other PEs.
Import target attribute—A PE checks the export target attribute of VPN-IPv4 routes received from
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other PEs. If the export target attribute matches the import target attribute of the VPN instance, the
PE adds the routes to the VPN routing table.
In other words, route target attributes define which sites can receive a VPN-IPv4 route, and from which
sites that a PE can receive routes.
Similar to RDs, route target attributes can be one of the following formats:
16-bit AS number:32-bit user-defined number. For example, 100:1.
•
32-bit IPv4 address:16-bit user-defined number. For example, 172.1.1.1:1.
•
32-bit AS number:16-bit user-defined number, where the minimum value of the AS number is 65536.
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For example, 65536:1.

MCE

BGP/MPLS VPN transmits private network data through MPLS tunnels over the public network. However,
the traditional MPLS L3VPN architecture requires each VPN instance use an exclusive CE to connect to a
PE, as shown in Figure 1.
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