H3C S9500 Series Operation Manual page 22

Operation Manual – MPLS L3VPN
H3C S9500 Series Routing Switches
Sham-links are required between two PEs when Backdoor links (that is, the OSPF links
that do not pass through the MPLS backbone network) exist between the two PEs and
data is expected to be transported over the MPLS backbone. A Sham-link between two
PEs is considered as a link in OSPF domain. Its source and destination addresses are
both the Loopback interface address with 32-bit mask, but this Loopback interface
should be bound to a VPN instance and direct routes must be imported into BGP by
BGP. OSPF processes of the VPN cannot directly import the routes of the Loopback
interface (so the import direct command cannot be executed in an OSPF processes of
VPN); instead, an OSPF process can only advertise the route indirectly by importing a
BGP route.
Perform the following configuration in the OSPF area view to configure Sham-link:
Configure Sham-link
Delete a Sham-link
By default, the cost value is 1, dead value is 40 seconds, hello value is 10 seconds,
retransmit value is 5 seconds and trans-delay value is 1 second.
4) Configure EBGP on PE
If you select EBGP between PE and CE, you should configure a neighbor for each VPN
in VPN instance address family sub-view, and import IGP route of CE.
Step 1: Configure peer group
Configuring peer group in VPN instance address family view to configure peer group:
Configure a peer group
Delete the specified peer group
By default, the peer group is configured as internal. When BGP mode is used for
PE-CE route switching, they often belong to different ASs, so you should configure
EBGP peer as external.
Step 2: Configure AS number for a specific neighbor and add group member to a peer
group
When EBGP mode is used for PE-CE route switching, you should configure AS number
for a specific neighbor for every CE VPN-instance.
Perform the following configuration in VPN instance address family view to configure
AS number for a specific neighbor:
To do...
sham-link source-addr destination-addr [ cost
cost-value ] [ simple password | md5 keyid key ] [ dead
seconds ] [ hello seconds ] [ retransimit seconds ]
[ trans-delay seconds ]
undo sham-link source-addr destination-addr
To do...
Chapter 1 MPLS L3VPN Configuration
Use the command...
Use the command...
group group-name [ internal | external ]
undo group group-name
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