5.4 Configuring Dial on Demand Routing (DDR)
5.4.2
Step 1 - Defining what constitutes interesting traffic

The dialer-list command is used to configure dial-on-demand calls that will initiate a connection. The simpler form of the command specifies whether a whole protocol suite, such as IP or IPX, will be permitted or denied to trigger a call. The more complex form references an access list, allowing finer control of the definition of interesting traffic.

The command syntax to define a DDR dialer list to control dialing by protocol is as follows:

Router(config)#dialer-list dialer-group-number protocol protocol-name {permit | deny}

You can also specify an access list for more refined control over the DDR process. Standard or extended access lists can be used for DDR, and then applied to dialer groups and interfaces. An extended access list gives you control over the protocol, source address, and destination address in determining interesting packets.

The access-list command specifies interesting traffic that initiates a DDR call. The dialer-list command is used in conjunction with the access list. This command associates the access list with the dialer access group:

Router(config)#access-list access-list-number [permit | deny]
{protocol | protocol-keyword}{source source-wildcard | any}
{destination destination-wildcard | any}
[protocol-specific-options] [log]

Router(config)#dialer-list dialer-group list access-list-number