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Cisco Router and Security Device Manager Version 2.2 Users Guide
OL-4015-08
Chapter11 DMVPN
Dynamic Multipoint VPN
Re-register with hub when IP address of interface-name changesThis option
is available when the interface you selected receives a dynamic IP address via
DHCP or IPCP. Specifying this option will allow the spoke to re-register with the
hub when it receives a new IP address.
IP Address
Enter the IP address for the GRE interface to this hub. This must be a private
address and be in the same subnet as the GRE interfaces of the other routers in the
network. For example, the GRE interfaces might share the subnet 10.10.6.0, and
be given IP addresses in the range 10.10.6.1 through 10.10.6.254.
If you are configuring a spoke router, you must use the IP address assigned to your
router by the hub administrator. Failure to do so may result in address conflicts.
Subnet Mask
Enter the mask for the subnet that the GRE interfaces are in. This mask must be
assigned by the hub administrator and be the same for all routers in the DMVPN.
For example, the mask for the subnet 10.10.6.0 could be 255.255.255.0. For more
information, see IP Addresses and Subnet Masks.

Advanced Button

Click this button to provide NHRP and tunnel parameters for this connection.
SDM provides default values for advanced tunnel settings. However, the hub
administrator must decide on the tunnel settings and give them to the personnel
administering spoke routers so that they can make matching settings. If you are
configuring a spoke router, obtain the tunnel settings from the hub administrator,
click this button, and enter them in the dialog box displayed.
SDM Warning: DMVPN Dependency
This window appears when the interface you have chosen for the DMVPN tunnel
source has a configuration that prevents its use for DMVPN. SDM informs you of
the conflict and gives you the option of allowing SDM to modify the configuration
so that the conflict is removed.