Cisco Unity Express is an entry-level auto-attendant (AA) and voicemail
system that is integrated with a Cisco IOS® router for small-to-medium business
or Enterprise branch offices that require up to 250 mailboxes. This document
describes the procedures to change the IP address of Cisco Unity Express
integrated with Cisco CallManager Express.
Cisco Unity Express is offered in two forms that can be added to the
router in the office:
Cisco recommends that you have knowledge of these topics:
The information in this document is based on these software and
Cisco 3725 Router that runs Cisco IOS Software Release
Cisco CallManager Express 4.1
Cisco Unity Express 2.3.4
The information in this document was created from the devices in a
specific lab environment. All of the devices used in this document started with
a cleared (default) configuration. If your network is live, make sure that you
understand the potential impact of any command.
Technical Tips Conventions for more information on document
The Cisco Unity Express module connects to its host router via a
back-to-back Ethernet configuration that physically travels across the
backplane of the router. The two IP addresses that can be configured on a Cisco
Unity Express are one for the service-engine interface and the other for the
internal IP address of the Cisco Unity Express module. For more information,
Infrastructure Considerations for Cisco Unity Express.
IP Unnumbered—The most common way to configure the
Cisco Unity Express module is to use the unnumbered IP address method. An
ip unnumbered command configuration allows the Cisco
Unity Express module to consume an IP address in the subnet of the network
associated with a particular router egress port, such as FastEthernet 0/0. The
router interface with which the Cisco Unity Express interface is associated
must be in an "up" state at all times for Cisco Unity Express to communicate.
Note: This method requires the configuration of a static route to the
In this case, only the IP address of the Cisco Unity Express and the
IP route towards the Cisco Unity Express module need to be
Stub Network—The stub network configuration requires
Cisco Unity Express to have its own IP subnet assigned, but does not require a
static route. The recommended approach to configure Cisco Unity Express when
you use a private address space is to use a stub network. When you implement a
stub network configuration, the IP address must be routable so that the
TFTP/FTP server used for software installation or backup-and-restore knows how
to reach the Cisco Unity Express module.
In the case of a stub network, you need to change of IP address of
both the service-engine interface and the internal Cisco Unity Express
VLAN—This configuration is required in a situation
in which an Etherswitch module is present in the router for which a VLAN
interface is most commonly used. A VLAN implementation also requires a static
When the Cisco Unity Express IP address needs to be changed, the IP
address that corresponds to the service-engine interface as well as the
internal IP address of the Cisco Unity Express module should be changed.
Complete these steps:
Change the IP address of the service-engine interface.
Change the internal IP address of the Cisco Unity Express module.
In order to do this, use the service-module ip
Change the IP address of the default gateway of the Cisco Unity
Express module (usually the IP address of the interface service-engine). In
order to do this, use the service-module ip
default-gateway command. Also change the IP routes and dial-peer
session targets that point toward the Cisco Unity Express with the new IP
Issue the shut and no
shut commands in the service-engine interface and reload the
Cisco Unity Express using the service-module service-Engine x/x