HP 7102dl - ProCurve Secure Router Configuration Manual page 842

IP Routing—Configuring RIP, OSPF, BGP, and PBR
Configuring BGP
15-116
prefers certain routes from certain neighbors to help distribute outbound
traffic over the connections
clears any policies on inbound routes that prevent the router from adver-
tising them as necessary
To configure the router's IGP and its connection to the BGP neighbors, see
"Example 2: Baseline BGP Configuration for a Router that Runs an IGP" on
page 15-111. The following steps guide you through one way of implementing
the BGP policies outlined above:
1. Configure two prefix lists, each of which selects half of the network space
that you want to advertise.
a. In this example, the LAN uses the 10.1.0.0 /16 network.
ProCurve(config)# ip prefix-list LAN1 seq 10 permit 10.1.0.0/17
ProCurve(config)# ip prefix-list LAN2 seq 10 permit 10.1.128.0/17
This configuration only allows the two exact routes entered. If nec-
essary, add null routes to the networks you have specified in the prefix
lists.
ProCurve(config)# ip route 10.1.0.0 /17 null 0
ProCurve(config)# ip route 10.1.128.0 /17 null 0
b. Alternatively, you could allow the router to advertise routes to indi-
vidual subnets in the specified range.
ProCurve(config)# ip prefix-list LAN1 seq 10 permit 10.1.0.0/17 ge 20 le 23
ProCurve(config)# ip prefix-list LAN2 seq 10 permit 10.1.128.0/17 ge 20 le 23
c. If you allow the router to advertise routes to individual subnets, you
might want to prevent the router from advertising routes to private
networks that no external hosts should be able to access (for exam-
ple, networks that include private servers). In this example, private
routes are routes to any subnet in the 10.1.240.0 /20 range.
ProCurve(config)# ip prefix-list LAN1 seq 10 permit 10.1.0.0/20 ge 20 le 23
ProCurve(config)# ip prefix-list LAN2 seq 10 deny 10.1.240.0/20 ge 20
ProCurve(config)# ip prefix-list LAN1 seq 20 permit 10.1.128.0/17 ge 20 le 23
2. If necessary, configure a prefix list that selects routes that you want to
advertise to the ISP, but that you do not want the ISP to export to other
autonomous systems.
ProCurve(config)# ip prefix-list Private seq 10 permit 10.1.128.0/20 ge 20