Controlling Route Distribution And Reception; Configuring Bgp Route Summarization - HPE 5800 Series Configuration Manual

Step
Enable route redistribution
3.
from IGP into BGP.
Enable default route
4.
redistribution into BGP.

Controlling route distribution and reception

Configuring BGP route summarization

To reduce the number of routes to be redistributed and the routing table size on medium and large
BGP networks, configure route summarization on BGP routers. BGP supports the following
summarization modes: automatic and manual. Manual summary routes have a higher priority than
automatic ones.
Configuring automatic route summarization
After automatic route summarization is configured, BGP summarizes redistributed IGP subnets to
advertise only natural networks. Routes injected with the network command cannot be summarized.
To configure automatic route summarization:
Step
Enter system view.
1.
Enter BGP view or
2.
BGP-VPN instance view.
Configure automatic route
3.
summarization.
Configuring manual route summarization
By configuring manual route summarization, you can summarize both redistributed routes and
routes injected using the network command and determine the mask length for a summary route as
needed.
The output interface of a BGP summary route is Null 0. With route summarization, BGP advertises
fewer routes to its peers. A summary route must not be optimal; otherwise, BGP will fail to forward
the packets matching the route. If a summarized specific route has the same mask as but has a
lower priority than the summary route, the summary route becomes the optimal route. In this case,
you must change the priority of the summary or the specific route to make the specific route as the
optimal route.
To configure BGP manual route summarization:
Step
Enter system view.
1.
Command
import-route protocol
[ { process-id | all-processes }
[ allow-direct | med med-value |
route-policy route-policy-name ]
* ]
default-route imported
Command
system-view
•
Enter BGP view:
bgp as-number
•
Enter BGP-VPN instance
view:
a. bgp as-number
b. ipv4-family
vpn-instance
vpn-instance-name
summary automatic
Command
system-view
188
Remarks
Not enabled by default.
The allow-direct keyword is
available only when the specified
routing protocol is OSPF.
Not enabled by default.
Remarks
N/A
Use either approach.
Not configured by default.
Remarks
N/A