Command Manual – MPLS 
Quidway S8500 Series Routing Switches  Chapter 2  BGP/MPLS VPN Configuration Commands
 
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backbone, you need to configure a Sham-link between the two PE routers. The sham 
link between VPN PE routers is taken as a link within the OSPF area. When configuring 
the Sham-link command, the optional parameters are not mutually exclusive. You can 
only choose in the undo command those parameters which are selected in the 
corresponding sham-link command.  
 
  Caution:  
z  The source and destination addresses of a sham link are both Loopback interface 
addresses with a 32-bit mask, which must be bound to a VPN instance and imported 
into BGP through a direct-connect route. 
z  In an OSPF processes of VPN, the Loopback interface routes used by the 
Sham-link cannot be imported directly (so the import direct command cannot be 
used in the OSPF processes of VPN). OSPF can only advertise the route by 
importing a BGP route. 
z  The source and destination addresses of a sham link cannot be the same. 
z  The same sham link cannot be configured for different OSPF processes. 
z  50 sham links can be configured for an OSPF process at most. 
 
Example 
# Configure a Sham-link, with its source address 1.1.1.1 and destination address 
2.2.2.2. 
[Quidway-ospf-100-area-0.0.0.1] sham-link 1.1.1.1 2.2.2.2 cost 100 
2.1.68  summary  
Syntax 
summary 
undo summary 
View 
VPN-instance subaddress family view  
Parameter 
None 
Description 
Use the summary command to enable BGP to perform auto summary to subnet 
routes.