Configuring OSPF Sham Links

You can create an intra-area link or sham link between two provider edge (PE) routers so that the VPN backbone is preferred over the back-door link. Each sham link is identified by the combination of a local endpoint address and a remote endpoint address.

To configure a sham link, include the sham-link statement:

sham-link {local address;}

To configure the local endpoint address, specify the local option.

Note: In Junos OS Release 9.6 and later, an OSPF sham link is installed in the routing table as a hidden route. Additionally, a BGP route is not exported to OSPF if a corresponding OSPF sham link is available.

For a list of hierarchy levels at which you can include this statement, see the statement summary section for this statement.

To configure the remote endpoint address, include the sham-link-remote statement.

sham-link-remote address {ipsec-sa name;demand-circuit;metric metric;}

To configure the OSPF interface as a demand circuit, include the demand-circuit statement. To configure the remote endpoint metric value, include the metric statement. To configure IPsec authentication for the remote endpoint of a sham link, include the ipsec-sa name statement.