In today's article, I'm going to quickly inform you about the Cisco IOS privileged EXEC mode (router#) command named “clear dmvpn session“.  Network administrators (like you) use the “clear dmvpn session” command to clear Dynamic Multipoint VPN (DMVPN) sessions.     

In other words, you can use this command to remove existing DMVPN sessions based on input parameters.     

Below is the command's syntax:     

clear dmvpn session [peer {nbma | tunnel ipv4-address | ipv6-address}] [interface tunnel number] [vrf vrf-name] [static]     

As you can see, this command has several (optional) keywords and arguments:     

peer – This (optional) keyword is used to specify a DMVPN peer.     

nbma – This (optional) keyword is used to specify nonbroadcast mapping access (NBMA).    

tunnel – This (optional) keyword is used to specify a tunnel.     

ipv4-address – This (optional) argument is the IPv4 address of a DMVPN peer.    

ipv6-address – This (optional) argument is the IPv6 address of a DMVPN peer.     

interface – This (optional) keyword is used to view the DMVPN information about a specific interface.     

tunnel number – This (optional) keyword with argument combination is used to specify the tunnel address for the DMVPN peer.     

vrf vrf-tunnel – This (optional) keyword with argument combination is used to clear (remove) all Next Hop Resolution Protocol (NHRP) sessions related to the specified virtual routing and forwarding (VRF) configuration.   

static – And, this (optional) keyword is used to clear all static and dynamic NHRP entries. Remember, if you decide not to use this keyword with the command; only dynamic NHRP entries will be cleared.  

By the way, if you decide to use the command, make sure your router(s) is running Cisco IOS 12.4(20)T or higher.    

I hope this article was very informative and helped you quickly understand the usage of the clear dmvpn session command. If you need to learn more; I suggest you visit my website, were you'll find the latest information regarding the Cisco CCNA (640-553) Security exam techniques.     

To your success,  

Source by Charles E Ross