H3C Technologies H3C S10500 Series Switches - Manual (Page 272)

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To do… Use the command… Remarks
Advertise routes permitted by a
specified routing policy to a UPE
peer { group-name | ip-address }
upe route-policy route-policy-name
export
By default, BGP does not advertise
default routes to a VPNv4 peer.
With the peer default-route-advertise vpn-instance command configured, the SPE always advertises a
default route using the local address as the next hop address to the UPE, regardless of whether the default
route is present in the local routing table or not.
NOTE:
•
The default routes of a VPN instance can be advertised to only a BGP peer or peer group that is UPE.
• Do not configure both the peer default-route-advertise vpn-instance command and the peer upe
route-policy command at the same time.
• Do not connect an SPE to a CE directly. If an SPE must be directly connected to a CE, the VPN instance
on the SPE and that on the UPE must be configured with different RDs.
Configuring an OSPF sham link
The sham link is considered an OSPF intra-area route. It is used to ensure that the VPN traffic is
transmitted over the backbone instead of the backdoor link between two CEs.
The source and destination addresses of the sham link must be loopback interface addresses with 32-bit
masks. Besides, the loopback interfaces must be bound to the VPN instances and be advertised through
BGP.
Configuration prerequisites
Before you configure an OSPF sham link, complete the following tasks:
• Configure basic MPLS L3VPN (OSPF is used between PEs and CEs)
• Configure OSPF in the LAN where CEs reside
Configuring a loopback interface
Follow these steps to configure a loopback interface:
To do… Use the command… Remarks
Enter system view system-view —
Create a loopback interface and
enter loopback interface view interface loopback
interface-number
Required
Bind the loopback interface to a
VPN instance ip binding vpn-instance
vpn-instance-name
Required
By default, an interface is
associated with no VPN instance.
Configure the address of the
loopback interface ip address ip-address { mask |
mask-length }
Required