H3C Technologies H3C S5560 Series Switches - Manual (Page 396)

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Configuring stub routers
A stub router is used for traffic control. It reports its status as a stub router to neighboring OSPFv3 routers.
The neighboring routers can have a route to the stub router, but they do not use the stub router to forward
data.
Use either of the following methods to configure a router as a stub router:
• Clear the R-bit of the Option field in Type-1 LSAs. When the R-bit is clear, the OSPFv3 router can
participate in OSPFv3 topology distribution without forwarding traffic.
• Use the OSPFv3 max-metric router LSA feature. This feature enables OSPFv3 to advertise its locally
generated Type-1 LSAs with a maximum cost of 65535. Neighbors do not send packets to the stub
router as long as they have a route with a smaller cost.
To configure a router as a stub router:
Step Command Remarks
1. Enter system view. system-view N/A
2. Enter OSPFv3 view.
ospfv3 [ process-id | vpn-instance
vpn-instance-name ] *
N/A
3. Configure the router as a
stub router.
• Method 1:
stub-router r-bit [ include-stub |
on-startup { seconds | wait-for-bgp
[ seconds ] } ] *
• Method 2:
stub-router max-metric
[ external-lsa [ max-metric-value ] |
summary-lsa [ max-metric-value ] |
include-stub | on-startup { seconds
| wait-for-bgp [ seconds ] } ] *
By default, the router is not
configured as a stub router.
A stub router is not related to a stub
area.
Configuring prefix suppression
By default, an OSPFv3 interface advertises all of its prefixes in LSAs. To speed up OSPFv3 convergence,
you can suppress interfaces from advertising all of their prefixes. This function helps improve network
security by preventing IP routing to the suppressed networks.
When prefix suppression is enabled:
• OSPFv3 does not advertise the prefixes of suppressed interfaces in Type-8 LSAs.
• On broadcast and NBMA networks, the DR does not advertise the prefixes of suppressed interfaces
in Type-9 LSAs that reference Type-2 LSAs.
• On P2P and P2MP networks, OSPFv3 does not advertise the prefixes of suppressed interfaces in
Type-9 LSAs that reference Type-1 LSAs.
IMPORTANT:
If you want to use prefix suppression, H3C recommends that you configure prefix suppression on all
OSPFv3 routers.