H3C Technologies H3C SR8800 - Manual (Page 355)

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100.1.1.2/32 Direct 0 0 127.0.0.1 InLoop0
120.1.1.0/24 OSPF 10 3126 100.1.1.1 GE4/1/1
4. Configure a sham link
# Configure PE 1.
[PE1] interface loopback 1
[PE1-LoopBack1] ip binding vpn-instance vpn1
[PE1-LoopBack1] ip address 3.3.3.3 32
[PE1-LoopBack1] quit
[PE1] ospf 100
[PE1-ospf-100] area 1
[PE1-ospf-100-area-0.0.0.1] sham-link 3.3.3.3 5.5.5.5 cost 10
[PE1-ospf-100-area-0.0.0.1] quit
[PE1-ospf-100] quit
# Configure PE 2.
[PE2] interface loopback 1
[PE2-LoopBack1] ip binding vpn-instance vpn1
[PE2-LoopBack1] ip address 5.5.5.5 32
[PE2-LoopBack1] quit
[PE2] ospf 100
[PE2-ospf-100] area 1
[PE2-ospf-100-area-0.0.0.1] sham-link 5.5.5.5 3.3.3.3 cost 10
[PE2-ospf-100-area-0.0.0.1] quit
[PE2-ospf-100] quit
After completing the configurations, issue the display ip routing-table vpn-instance command again on
the PEs. You can see that the path to the peer CE is now along the BGP route across the backbone, and
that a route to the sham link destination address is present. Take PE 1 as an example:
[PE1] display ip routing-table vpn-instance vpn1
Routing Tables: vpn1
Destinations : 6 Routes : 6
Destination/Mask Proto Pre Cost NextHop Interface
3.3.3.3/32 Direct 0 0 127.0.0.1 InLoop0
5.5.5.5/32 BGP 255 0 2.2.2.9 NULL0
20.1.1.0/24 OSPF 10 1563 100.1.1.1 GE4/1/1
100.1.1.0/24 Direct 0 0 100.1.1.2 GE4/1/1
100.1.1.2/32 Direct 0 0 127.0.0.1 InLoop0
120.1.1.0/24 BGP 255 0 2.2.2.9 NULL0
Issue the display ip routing-table command on the CEs. You can see that the cost of the OSPF route to the
peer CE is now 10 (the cost configured for the sham link), and that the next hop is now the
GigabitEthernet interface connected to the PE. This means that VPN traffic to the peer will be forwarded
over the backbone. Take CE 1 as an example:
[CE1] display ip routing-table
Routing Tables: Public
Destinations : 9 Routes : 9
Destination/Mask Proto Pre Cost NextHop Interface
20.1.1.0/24 Direct 0 0 20.1.1.1 POS2/1/1
20.1.1.1/32 Direct 0 0 127.0.0.1 InLoop0
20.1.1.2/32 Direct 0 0 20.1.1.2 POS2/1/1