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Cisco Router and Security Device Manager Version 2.2 User’s Guide
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Chapter30 More About....
DMVPN Configuration Recommendations
Assigning Spoke Addresses
All routers in the DMVPN must be in the same subnet. Th erefore, the hub
administrator must assign addresses in the subnet to the spoke routers so that
address conflicts do not occur, and so that everyone is using the same subnet
mask.
Recommendations for Configuring Routing Protocols for DMVPN
The following are guidelines that you should note when configuring routing
protocols for DMVPN. You can choose to ignore these guidelines, but SDM has
not been tested in scenarios outside the guidelines and may not be able to let you
edit configurations within SDM after you enter them.
These recommendations are listed in best-choice order:
•If a routing process exists that advertises inside networks, use this process to
advertise networks to the DMVPN.
•If a routing process exists that advertises tunnel networks for VPNs, for
example GRE over IPSec tunnels, use this process to advertise the DMVPN
networks.
•If a routing process exists that advertises networks for the WAN interfaces,
then be sure to use an AS number or process ID that the WAN interfaces do
not use to advertise networks.
•When you configure DMVPN routing information SDM checks whether the
Autonomous System number (EIGRP) or area ID (OSPF) you enter is already
used to advertise networks for the router’s physical interface. If the value is
already in use, SDM informs you of this and recommends that you either use
a new value, or that you select a different routing protocol to advertise
networks on the DMVPN.
Using Interfaces with Dialup Configurations
Selecting an interface that uses a dialup connection may cause the connection to
be always up. You can examine supported interfaces in Interfaces and
Connections to determine if a dialup connection, such as an ISDN or Async
connection has been configured for the physical interface you selected.