Cisco Cisco IOS Software Release 12.4(6)T

© 2006 Cisco Systems, Inc. All rights reserved.

Routers in a Dynamic Multipoint VPN (DMVPN) network use Next Hop Resolution Protocol (NHRP) 
to discover the addresses of other routers and networks behind those routers that are connected to a 
nonbroadcast multiaccess (NBMA) DMVPN. The shortcut switching enhancements for NHRP provide 
an Address Resolution Protocol (ARP)-like solution that alleviates NBMA network problems, such as 
hub failure, decreased reliability,

 

and complex configurations. With NHRP, systems attached to an 

NBMA network dynamically learn the NBMA address of the other systems that are part of that network, 
allowing these systems to directly communicate without requiring traffic to use an intermediate hop.

Your Cisco IOS software release may not support all of the features documented in this module. To reach 
links to specific feature documentation in this module and to see a list of the releases in which each feature is 
supported, use the 

.

Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image 
support. Access Cisco Feature Navigator at 

. You must have an account on 

Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at 
the login dialog box and follow the instructions that appear.