The EIGRP Scale for
DMVPN feature provides an increase in hub scalability for Dynamic Multipoint
VPN (DMVPN). Cisco DMVPN is a security solution for building scalable
enterprise VPNs that support distributed applications such as voice and video.
Your software release
may not support all the features documented in this module. For the latest
caveats and feature information, see
Bug Search Tool and the
release notes for your platform and software release. To find information about
the features documented in this module, and to see a list of the releases in
which each feature is supported, see the feature information table.
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VPN (DMVPN) improves the usage of spoke-to-spoke networks. However, scaling of
routing protocols and optimization of routing updates in large scale DMVPN
networks remain a challenge. These challenges pertain to neighbor discovery,
overhead reduction, and building upon the recent enhancements in the area of
scaling routing over DMVPN. IPSEC tunnels, Next Hop Resolution Protocol (NHRP)
and Enhanced Interior Gateway Routing Protocol (EIGRP) are established during
initial startup of a DMVPN network. It is possible that EIGRP may not process
and respond to inbound packets waiting in the interface or socket queue causing
the spokes to time out and retransmit which worsens the resource contention
issue. The EIGRP Scale for DMVPN feature provides an increase in the
scalability of the hub device to 2500 sessions. The increase in the number of
sessions reduces the adverse impact on CPU, system buffers, interface buffers,
and queues and it reduces resource contention on the hub during initial startup
of a DMVPN network. In a typical EIGRP DMVPN setup, spokes are configured as
This EIGRP Scale for DMVPN feature is enabled by default and does not
have a configuration task.
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The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to
www.cisco.com/go/cfn. An account on Cisco.com is not required.
Scale for DMVPN
XE Release 3.12S
Scale for DMVPN feature provides an increase in hub scalability for Dynamic
Multipoint VPN (DMVPN).