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Creating a sham link
To create a sham link:
To do…
Use the command…
Remarks
Enter system view
system-view
—
Enter OSPF view
ospf
[
process-id
|
router-id
router-id
|
vpn-instance
vpn-instance-name
] *
—
Configure the external route tag for
imported VPN routes
route-tag
tag-value
Required
Enter OSPF area view
area
area-id
Required
Configure a sham link
sham-link
source-ip-address
destination-ip-address
[
cost
cost
|
dead
dead-interval
|
hello
hello-interval
|
retransmit
retrans-interval
|
trans-delay
delay
|
simple
[
cipher
|
plain
]
password
| {
md5
|
hmac-md5
}
key-id
[
cipher
|
plain
]
password
]*
Required
By default, no sham link is
configured.
NOTE:
•
If you start OSPF but do not configure the router ID, the system will automatically elect one. However, the
same election rules produce the same router ID. HP recommends that you configure the router ID when
starting an OSPF process. For the election rules, see
Layer 3—IP Routing Configuration Guide.
•
If you configure multiple OSPF VPN instances but do not configure the route tag, the system will
automatically create one based on the AS number configured. If you do not configure BGP, the tag will
be 0. However, the same calculation rule produces the same tag, and hence the same tag will be created
for multiple OSPF VPN instances on the same PE or PEs with the same AS number. Therefore, HP
recommends configuring different tags for different OSPF VPN instance.
Configuring routing on an MCE
MCE implements service isolation through route isolation. MCE routing configuration includes:
•
MCE-VPN site routing configuration
•
MCE-PE routing configuration
On the PE in an MCE network environment, disable routing loop detection to avoid route loss during
route calculation and disable route redistribution between routing protocols to save system resources.
Configuration prerequisites
Before you configure routing on an MCE, complete the following tasks:
•
On the MCE, configure VPN instances, and bind the VPN instances with the interfaces connected
to the VPN sites and those connected to the PE.
•
Configure the link layer and network layer protocols on related interfaces to ensure IP connectivity.
