Arcserve Backup Cannot Communicate after Changing the IP Address of an Arcserve Backup Server

Troubleshooting › Log in Problems › Arcserve Backup Cannot Communicate after Changing the IP Address of an Arcserve Backup Server

Arcserve Backup Cannot Communicate after Changing the IP Address of an Arcserve Backup Server

Valid on Windows platforms.

Overview

There are several reasons why the IP address would be changed on an Arcserve Backup server. Some of the common reasons are as follows:

The network interface card (NIC) was replaced in an Arcserve Backup server. When the computer rejoins the network, the IP address is different from that of the previous network card.
The Arcserve Backup server communicates with a DHCP server to obtain an IP address and the Arcserve Backup server connects to a different DHCP server.

Symptoms

After you change the IP address on a primary server, a stand-alone server, and a system hosting the Arcserve Backup Manager Console, Arcserve Backup demonstrates the following behavior:

On a member server and a system hosting the Arcserve Backup Manager Console, the value of the Domain is "None" in the Default Server and Security fields on the Manager Console.
Error messages appear when you click the Backup link in the Navigation Bar on the member server. For example, a pop-up message appears "Connecting to primary server."
Pinging the primary server from the Command Line on a member server, returns the message "Request timed out."
Equivalence errors may occur when you execute a task using an Arcserve Backup command line utility on the primary server or a stand-alone server. For example, one of the following messages may appear:
```
Ntuser not validated in authentication server on Hostname.
Do you want to create equivalence (default : y)?
```

After you change the IP address on a member server, Arcserve Backup demonstrates the following behavior:

On a member server, the value of the Domain is "None" in the Default Server and Security section on the Manager Console.
From the primary server or a system hosting the Arcserve Backup Manager Console, you cannot log in to the member server.
Pinging a member server from the Command Line on the primary server, returns the message "Request timed out."
Equivalence errors may occur when you execute a task using an Arcserve Backup command line utility on a member server. For example, one of the following messages may appear:
```
Ntuser not validated in authentication server on Hostname.
Do you want to create equivalence (default : y)?
```

Solutions

To remedy the communication problems, use the procedure that corresponds with the type of Arcserve Backup server where the IP address was changed.

IP Address Changed on the Primary Server or Stand-alone Server

Important! After you change the IP address of a primary server or a stand-alone server, basic backup jobs and restore jobs from the server itself can complete successfully. Additionally, the host names of the member servers should display in the Arcserve Backup managers on the primary server. However, to ensure that you can successfully complete backup jobs and restore jobs on member servers, you must complete the modification described in Step 1 on the member server before completing any other task.

If the Arcserve Backup server is a primary server, stop and restart the Arcserve Backup services using the following commands:
- cstop
- cstart
If there are member servers in your Arcserve Backup domain, open the Windows Command Line the member server.
Execute the ipconfig command using the /flushdns switch. For example:
```
c:\documents and settings\windows user name>ipconfig /flushdns
```
Note: You must repeat this step on all member servers in your Arcserve Backup domain.
Create equivalence on the primary server or stand-alone server using the ca_auth command. The syntax for this task is as follows:
```
ca_auth [-cahost HOST-NAME] -equiv add ntuser HOST-NAME ARCserveBackupUser [caroot_username]  [caroot_password]
```
Note: For more information about using the ca_auth command, see the Command Line Reference Guide.

IP Address Changed on a Member Server

Create equivalence on the member server using the ca_auth command. The syntax for this task is as follows:
```
ca_auth [-cahost HOST-NAME] -equiv add ntuser HOST-NAME ARCserveBackupUser [caroot_username]  [caroot_password]
```
Note: For more information about using the ca_auth command, see the Command Line Reference Guide.
Open the Windows Command Line on the primary server.
Execute the ipconfig command using the /flushdns switch. For example:
```
c:\documents and settings\windows user name>ipconfig /flushdns
```

IP Address Changed on a Server that is Hosting the Arcserve Manager Console

No action is required when the IP address is changed on a server that is hosting the Arcserve Backup Manager Console. You can continue to manage other Arcserve Backup servers without experiencing communication problems.

IP Address Changed on an Agent System

Select one of the following corrective actions:

Open the Windows Command Line on the Arcserve Backup server that is backing up the agent system.
Execute the ipconfig command using the /flushdns switch. For example:
```
c:\documents and settings\windows user name>ipconfig /flushdns
```
If you added the agent system to the primary server, a member server, or a stand-alone server by referencing the IP address rather than the agent system's host name, you can log in the Arcserve Backup server and manually change the IP address of the agent system. To do this, complete the following steps:
1. Log in to the Arcserve Backup server, open the Backup Manager, and expand the Windows system object.
2. Right-click the agent system and select Modify Agent from the pop-up menu.
  The Agent Option dialog opens.
3. Specify the new IP address in the IP address field and click OK.
  The new IP address is applied to the agent system.

IP Address Changed on a System Using a Static IP Address

Select one of the following corrective actions:

When you use a static IP address, you can register the new static IP address on the DNS server. Based on the type of server (for example, a primary server, member server, and so on), use the ipconfig command task described in the previous sections to refresh their local DNS client.
This action lets you resolve the cache for establishing a new relationship between the host name and IP address.
If you do not register the new static IP address with the DNS server, you must modify the Hosts file on the servers to reflect this change.
To remedy this scenario, do the following:
1. From Windows Explorer, open the following file using a text editing application such as Notepad:
```
C:\WINDOWS\system32\drivers\etc\hosts
```
2. Specify the static IP address and host name of the system as illustrated by the following screen:
1. Close the file and save the changes.
Note: When you use this solution, you must modify the Hosts file when you change the IP address, and delete the specified information when you revert to a dynamic IP address.