IP Address, Hostname, and Other Network Identifier Changes
You can change the network-level IP address and hostname name of nodes in your deployment for a variety of reasons, including moving the node from one cluster to another or resolving a duplicate IP address problem. The IP address is the network-level Internet Protocol (IP) associated with the node, and the Hostname is the network-level hostname of the node.
Note |
All Unified Communications products such as Cisco Unified Communications Manager, Cisco Unity Connections, and Cisco IM and Presence, and so on, have only one interface. Thus, you can assign only one IP address for each of these products. |
For changes to other network identifiers, such as the node name and domain name, see the following resources:
-
System Configuration Guide for Cisco Unified Communications Manager
-
Configuration and Administration Guide for the IM and Presence Service
-
Installation Guide for Cisco Unified Communications Manager and the IM and Presence Service
For IM and Presence Service, instructions to change the node name and the network-level DNS default domain name for the node are also included in this document.
IM and Presence Service Node Name and Default Domain Name Changes
The node name is configured using Cisco Unified CM Administration GUI and must be resolvable from all other IM and Presence Service nodes and from all client machines. Therefore, the recommended node name value is the network FQDN of the node. However, both IP address and hostname are also supported as values for the node name in certain deployments. See the Hostname Configuration for more information about node name recommendations and the supported deployment types.
The network-level DNS default domain name of the node is combined with the hostname to form the Fully Qualified Domain Name (FQDN) for the node. For example, a node with hostname "imp-server" and domain "example.com" has an FQDN of "imp-server.example.com".
- The network-level DNS default domain is used only as a network identifier for the node.
- The enterprise-wide IM and Presence Service domain is the application-level domain that is used in the end-user IM address.
You can configure the enterprise-wide domain using either Cisco Unified CM IM and Presence Administration GUI or Cisco Unified Communications Manager Administration. See the Deployment Guide for IM and Presence Service on Cisco Unified Communications Manager for more information about enterprise-wide domains and the supported deployment types.
Hostname Configuration
The following table lists the locations where you can configure a host name for the Unified Communications Manager server, the allowed number of characters for the host name, and the recommended first and last characters for the host name. Be aware that, if you do not configure the host name correctly, some components in Unified Communications Manager, such as the operating system, database, installation, and so on, may not work as expected.
Host Name Location |
Allowed Configuration |
Allowed Number of Characters |
Recommended First Character for Host Name |
Recommended Last Character for Host Name |
---|---|---|---|---|
Host Name/ IP Address field in Cisco Unified Communications Manager Administration |
You can add or change the host name for a server in the cluster. |
2-63 |
alphabetic |
alphanumeric |
Hostname field Cisco Unified Communications Manager installation wizard |
You can add the host name for a server in the cluster. |
1-63 |
alphabetic |
alphanumeric |
Hostname field in Cisco Unified Communications Operating System |
You can change, not add, the host name for a server in the cluster. |
1-63 |
alphabetic |
alphanumeric |
set network hostname hostname Command Line Interface |
You can change, not add, the host name for a server in the cluster. |
1-63 |
alphabetic |
alphanumeric |
Tip |
The host name must follow the rules for ARPANET host names. Between the first and last character of the host name, you can enter alphanumeric characters and hyphens. |
Before you configure the host name in any location, review the following information:
- The Host Name/IP Address
field in the Server Configuration window, which supports device-to-server,
application-to-server, and server-to-server communication, allows you to enter
an IPv4 address in dotted decimal format or a host name.
After you install the Unified Communications Manager publisher node, the host name for the publisher automatically displays in this field. Before you install a Unified Communications Manager subscriber node, enter either the IP address or the host name for the subscriber node in this field on the Unified Communications Manager publisher node.
In this field, configure a host name only if Unified Communications Manager can access the DNS server to resolve host names to IP addresses; make sure that you configure the Cisco Unified Communications Manager name and address information on the DNS server.
Tip |
In addition to configuring Unified Communications Manager information on the DNS server, you enter DNS information during the Cisco Unified Communications Manager installation. |
- During the installation of the Unified Communications Manager publisher node, you enter
the host name, which is mandatory, and IP address of the publisher node to
configure network information; that is, if you want to use static networking.
During the installation of a Unified Communications Manager subscriber node, you enter the hostname and IP address of the Unified Communications Manager publisher node, so that Unified Communications Manager can verify network connectivity and publisher-subscriber validation. Additionally, you must enter the host name and the IP address for the subscriber node. When the Unified Communications Manager installation prompts you for the host name of the subscriber server, enter the value that displays in the Server Configuration window in Cisco Unified Communications Manager Administration; that is, if you configured a host name for the subscriber server in the Host Name/IP Address field.