3Com Switch 8800 Configuration Guide
Chapter 37 BGP/MPLS VPN Configuration
37-13
3)
Configure vpn-instance description
Perform the following configuration in vpn-instance view
Table 37-5
Configure vpn-instance description
Operation
Command
Configure vpn-instance description
description
vpn
-
instance
-
description
Delete vpn-instance description
undo description
4)
Configure vpn-target attribute for the vpn-instance
VPN-target attribute, a BGP extension community attribute, controls advertisement of
VPN routing information.
The following is the advertisement controlling process of VPN routing information:
z
When BGP is imported into a VPN route learned at CE, it associates a VPN-target
extension community attribute list for the route. Usually the list is the VPN-instance
output routing attribute list which is associated with CE.
z
VPN instance defines input routing attribute list according to the
import-extcommunity
in VPN-target, defines the acceptable route range and
import it.
z
VPN instance modifies VPN-target attributes for the routes to be advertised,
according to the
export-extcommunity
in VPN-target.
Like an RD, an extension community includes an ASN plus an arbitrary number or an IP
address plus an arbitrary number. There are two types of formats:
The first one is related to autonomous system number (ASN), in the form of 16-bit ASN
(can be 0 here): 32-bit user-defined number, for example, 100:1.
The second one is related to IP address, in the form of 32-bit IP address (can be 0.0.0.0
here):16-bit user-defined number, for example, 172.1.1.1:1.
Perform the following configuration in the vpn-instance view.
Table 37-6
Configure vpn-target attribute for the vpn-instance
Operation
Command
Configure vpn-target attribute for the
vpn-instance
vpn-target
vpn
-
target
-
extcommunity
[
import-extcommunity
|
export-extcommunity
|
both
]
Delete the specified route-target
attribute from the vpn-target attribute
list associated with the vpn-instance
undo vpn-target
vpn
-
target
-
extcommunity
[
import-extcommunity
|
export-extcommunity
|
both
]