Setting Up the Network
How to Set Up the Network
72
Cisco Unified SCCP and SIP SRST System Administrator Guide
OL-13143-04
DETAILED STEPS
Defining the DHCP Relay Server
This task sets up DHCP relay on the LAN interface where the Cisco Unified IP phones are connected
and enables the Cisco IOS DHCP server feature to relay requests from DHCP clients (phones) to a DHCP
server. For further details about DHCP configuration, see the
Cisco IOS DHCP Server
document.
The Cisco IOS DHCP server feature is enabled on routers by default. If the DHCP server is not enabled
on your Cisco Unified SRST router, use the following steps to enable it.
SUMMARY STEPS
1.
service dhcp
2.
interface
type
number
3.
ip helper-address
ip-address
4.
exit
Command or Action
Purpose
Step 1
ip dhcp pool
pool-name
Example:
Router(config)# ip dhcp pool pool2
Creates a name for the DHCP server address pool
and enters DHCP pool configuration mode.
Step 2
host
ip-address subnet-mask
Example:
Router(config-dhcp)# host 10.0.0.0 255.255.0.0
Specifies the IP address that you want the phone to
use.
Step 3
option 150 ip
ip-address
Example:
Router(config-dhcp)# option 150 ip 10.0.22.1
Specifies the TFTP server address from which the
Cisco IP phone downloads the image
configuration file. This needs to be the IP address
of Cisco Unified CM.
Step 4
default-router
ip-address
Example:
Router(config-dhcp)# default-router 10.0.0.1
Specifies the router to which the Cisco
Unified IP phones are connected directly.
•
This router should be the Cisco Unified SRST
router because this is the default address that
is used to obtain SRST service in the event of
a WAN outage. As long as the
Cisco IP phones have a connection to the
Cisco Unified SRST router, the phones are
able to get the required network details.
Step 5
exit
Example:
Router(config-dhcp)# exit
Exits DHCP pool configuration mode.
