HP 7102dl - ProCurve Secure Router Configuration Manual page 755

N o t e
Router A
Network 2
10.1.2.0 /24
Network 1
10.1.1.0 /24
Figure 15-4. Network That Cannot Use Route Summaries
For example, in Figure 15-4, Router B connects to Router A through subnet
1.1.1.0 /30, and to Router C through subnet 2.2.2.0 /30. Both Router A and C
attempt to advertise network 10.0.0.0 /8. When the route is accurate for
Network 3, Router B misroutes traffic to Networks 1 and 2 and vice versa. In
network environments such as this one, you must disable auto-summary so
that Router C can advertise Network 2 as 10.1.2.0 /24, and Router A can do the
same for its local networks.
You cannot use route summaries when your network includes non-contiguous
subnets. Disable auto summarization under these conditions:
The router connects to subnets in the same classful network through at
least two different connections.
These connections cross a classful network boundary.
To disable route summarization, enter:
ProCurve(config-rip)# no auto-summary
You cannot disable route summaries for RIP v1. (Although you can enter the
no auto-summary command in conjunction with RIP v1, RIP v1 will continue
to use route summaries.) If your network includes discontinuous subnets, you
must use RIP v2.
IP Routing—Configuring RIP, OSPF, BGP, and PBR
WAN Connection
1.1.1.0 /30
Router B
Router C
Network 3
10.1.3.0 /24
Configuring RIP
Network 1 Next hop A
Network 2 Next hop A
Network 3 Next hop C
WAN Connection
2.2.2.0 /30
15-29