Technical data

Step 11—Configuring DDR
Dial Solutions Quick Configuration Guide
2-36
Step 11—Configuring DDR
Dial-on-demand routing (DDR) provides a mechanism to establish and maintain connectivity over
a circuit switched network, such as the PSTN. DDR also supports remote LANs by maintaining
IP routes to the remote sites when they are not connected.
Configure
To configure the dialer interfaces, use the following commands beginning in global configuration
mode:
Step Command Purpose
1
hq-sanjose(config)# interface dialer 1
hq-sanjose(config-if)# ip address 10.1.254.1 255.255.255.0
Create interface dialer 1 and enable IP routing.
2
hq-sanjose(config-if)# exit
Exit back to global configuration mode.
3
hq-sanjose(config)# interface serial 0:23
hq-sanjose(config-if)# dialer rotary-group 1
hq-sanjose(config-if)# exit
Group serial 0’s channels into dialer 1.
4
hq-sanjose(config)# interface serial 1:23
hq-sanjose(config-if)# dialer rotary-group 1
hq-sanjose(config-if)# exit
hq-sanjose(config)# interface serial 2:23
hq-sanjose(config-if)# dialer rotary-group 1
hq-sanjose(config-if)# exit
hq-sanjose(config)# interface serial 3:23
hq-sanjose(config-if)# dialer rotary-group 1
hq-sanjose(config-if)# exit
Group the remaining serial channels into
dialer 1.
5
hq-sanjose(config)# interface dialer 1
Now with all the D channels grouped together,
return to dialer 1.
6
hq-sanjose(config-if)# encapsulation ppp
Encapsulate the packets with PPP.
7
hq-sanjose(config-if)# peer default ip address pool dialin_pool
Assign an address pool to interface dialer 1.
This step supports remote node ISDN devices,
such as those running Easy IP and PAT
1
.
8
hq-sanjose(config-if)# dialer in-band
Specify that this is an in-band dialer interface,
which enables passing the phone number
across the D channel.
9
hq-sanjose(config-if)# dialer idle-timeout 1800
Configure the idle timeout, which is set to
1800 seconds (30 minutes) in this example
2
.
10
hq-sanjose(config-if)# dialer-group 2
Define the interesting packets, which are
packets that reset the idle timer or trigger calls.
This dialer filter is defined by the dialer-list 2
command. See Step 17
3
.
11
hq-sanjose(config-if)# ppp multilink
Enable PPP multilink, which fragments and
reassembles packets among bundled B
channels.
12
hq-sanjose(config-if)# ppp authentication chap pap
Enable CHAP and PAP authentication. CHAP
is used first. PAP is the second choice.
13
hq-sanjose(config-if)# no fair-queue
Disable fair queuing.
14
hq-sanjose(config-if)# no cdp enable
Disable the Cisco discovery protocol, unless
you are using it for a specific purpose.
15
hq-sanjose(config-if)# no ip mroute-cache
Turn off multicast route caching.