Step 2-1 Enable or Disable IKE

Step 2-1 Enable or Disable IKE

The first step in configuring IKE is to make sure IKE is globally enabled. While IKE is enabled globally by default, the crypto isakmp enable command makes sure the feature is on. Use the no form of the command to disable IKE. Because IKE is a global mode command, it needn’t be enabled or disabled for individual interfaces. Some circumstances might warrant using an ACL entry to block ISAKMP access (UDP port 500) on interfaces not being used for IPSec to reduce the chances of a denial of service (DoS) attack. The command syntax and an example follow.

Rtr2(config)# crypto isakmp enable Rtr2(config)# no crypto isakmp enable