If the optional MAICP3 channel adapter is installed and an external network is configured, Windows data can direct data to the MCP via the external network. For this routing to occur, NetBIOS Name Resolution must resolve the MCP host name to the MAICP3 address in the MCP environment.
To manually direct data to use the external network path, complete the following procedure.
Step Action
1 If any shares on the MCP server are mapped to drives, use Explorer to disconnect them.
2 On the MCP server, issue the appropriate command for an LX7100 system from an ODT window to disable EVLAN mapping to the Windows server:
NW TCPIP MAPPING - 192.168.16.1
On the MCP server, issue the appropriate command for a Libra 4000 system from an ODT window to disable EVLAN mapping to the Windows server:
NW TCPIP MAPPING - 192.168.16.5 3 Log on to the Windows server.
Step Action
4 Using Notepad, create an LMHOSTS file, or modify the existing file.
a. Include the following parameters in the file:
<IP address> <MCP host name> #PRE where:
<IP address> is address of NP 200 in the MCP host. This address may have been changed from the preconfigured value shown in the example (refer to Table 4-2).
<MCP host name> is the current host name, which may have been changed from the preconfigured value shown in the example.
b. Enter “####” before the following line (this changes the statement into a comment):
#INCLUDE... lmhost.cnp Example
In an LX7100 system, to direct data from any Windows server to the MCP environment, type
192.168.237.10 CPMCP1 #PRE
The #PRE extension directs Windows to use the indicated address first for sending data to the MCP host.
5 Save the LMHOSTS file as
%systemroot%\system32\drivers\etc\lmhosts
6 If DNS servers are not configured, there is no need to configure a HOSTS file.
Skip to step 8.
Otherwise, create a new file (or use the sample HOSTS file located at
%systemroot%\System32\Drivers\etc\hosts.sam) and update the file as follows:
a. Copy all LMHOSTS file entries (created in step 4) into the HOSTS file.
b. Ensure that there are no statements for the EVLAN data path. If necessary, remove (or comment out) statements that map to the EVLAN data path.
Note: The HOSTS file does not support the use of keyword extensions such as #PRE. These extensions are ignored (recognized as comments).
7 Save the HOSTS file as
%systemroot%\system32\drivers\etc\hosts
Step Action
8 To complete the data path redefinition process, perform either of the following tasks:
• Reboot the Windows server, or
• Perform the following steps:
a. Enter nbtstat -R at the MS-DOS command prompt on the Windows server. This command purges and refreshes the NetBIOS name cache.
b. Enter netstat 10 at the MS-DOS command prompt on the Windows server. This command form continuously displays (at 10 second intervals) all active TCP/IP connections.
Initially, the MCP server connection will probably be in a Time_Wait state. For example:
TCP CP-NTA:1233 CP-MCP1:nbsession TIME_WAIT Note: Per TCP standard, the original connection remains active in a Time_Wait state for up to two Maximum Segment Lifetimes (MSL) after a connection closure is requested. Typically, this Time_Wait period will last approximately four minutes.
c. Monitor the returned TCP/IP connection status until the MCP server connection is no longer on the list.
d. Press Ctrl+C to terminate the netstat command sequence.
e. Now, traffic from the Windows server to the MCP server will use the external LAN data path.
Directing MCP Data to the Windows Environment
Normally, dialogs are initiated from the Windows server environment. In the following cases, however, data transfers are initiated from the MCP environment:
• When you issue an NW TCPIP PING command to determine if a remote host is available
• When you use the File Transfer Protocol (FTP) command
In these cases, you need to specify either the IP address or the host name for the applicable Windows server.
Using the NW TCPIP PING Command
Note: The default firewall rules for a Libra 4000 server will prevent PING commands initiated from the MCP over the EVLAN path. For information on changing the firewall rules, see the Libra 4000 Server MCP Partition Software Operations Guide.
If you use the IPADDR option of the NW TCPIP PING command, enter the exact address shown in the example.
If you use the HOSTNAME option of the command, enter the current host name, which may have been changed from the preconfigured value shown in the example.
For example:
• In a Libra 450 server, to direct data from CPMCP1 to the Windows server via the EVLAN, enter
NW TCPIP PING IPADDR = 192.168.16.2 or
NW TCPIP PING HOSTNAME = CPNTA
Note: The TCPIP PING command HOSTNAME option will only work if the hostname has been mapped to the IP address of the Windows server. This mapping is
provided in the MCP environment’s default TCP/IP initialization file. However, if you changed your MCP configuration (as specified in “Updating the MCP
Configuration”, earlier in this section), this mapping may have been removed.
• In a Libra 460 server, to direct data from CPMCP1 to the Windows server via the external network, enter
NW TCPIP PING IPADDR = <external IP address>
Note: The Default Windows server (shared adapter) address is 192.168.237.50
For More Information
For more information on the automated procedure for directing data to take the virtual LAN data path, see “Installing Network Services” and “How the Setup Program Manages the LMHOSTS File” in Section 2.
Specifying the WINS Server Address
Windows servers in ClearPath MCP systems were previously shipped with the WINS service installed. Due to the issues with WINS on multihomed systems, WINS is no longer preinstalled. If you want to install the WINS server, please see NX/NET FAQ 10011990 on the Support Web page and review the articles on WINS and multihomed systems in the Microsoft Knowledge Base.
If you have a WINS server somewhere in your network, specify its IP address to each Windows server within the ClearPath MCP system. You can enter this address at the WINS Address tab of the TCP/IP Properties Sheet.
You must also inform Client Access Services of the WINS server address as described in the following table:
Step Action
1 At the ST, switch to or initiate the Administration Center application. If
necessary, connect to the MCP server specifying its hostname and a privileged usercode, such as ADMINISTRATOR.
2 From the Resources menu, choose Create or Modify.
3 Another menu appears. Choose Server Properties.
4 On the Server Properties on <Server Name> screen a. Select the WINS Server tab.
b. Type a primary WINS server IP address and/or secondary WINS server IP address.
c. Choose Modify.
5 Administration Center displays a message stating that the change will not take effect until you save the configuration. Choose OK.
6 From the Resources menu, choose Save.
7 Administration Center displays a message, asking if you want to make the changes permanent. Choose Yes.
For More Information
For more information on WINS configuration, see the WINS Manager help.
Rebooting the System Environments
If you have not already done so, reboot the MCP and Windows server environments as described in the following table. The configuration changes for each of these environments do not take effect until they are restarted.
Step Action 1 Shut down the MCP environment as follows:
For Libra Model 400 and FS1700 servers:
a. Activate the Console window.
b. Click the Halt button on the tool bar if the system is running, started, or not responding. Wait until the partition status indicates that the partition has halted.
c. From the MCP menu, choose Shutdown MCP Control. Wait until the status line indicates that MCP Control and OPM have been shut down.
2 Reboot the Windows server by following the procedure in Section 7, “Stopping and Starting the Windows Server”.
Verifying the System Networking Configuration
Verify the system networking environment configuration as follows:
Step Action
1 Switch to or initiate the Administration Center application. If necessary, connect to the MCP server specifying its hostname and a privileged usercode, such as ADMINISTRATOR.
2 Verify that the application connects to the MCP by seeing that the MCP server name appears in the Connected MCP Server(s) dialog box on the toolbar.
3 Terminate Administration Center.
Controlling the Maximum Transmission Unit (MTU) Value
The USERFCMTU option provides control of the maximum transmission unit (MTU) value for TCP/IP. This option is set by default on ClearPath MCP servers. As a result, TCP/IP uses a maximum transmission size of 536. This low value is chosen to comply with RFC 1122, and might help to prevent fragmentation of a datagram by intermediate gateways along the path.
Note: Before making any changes to the USERFCMTU option, you should determine the minimum MTU value of all gateways and nodes in the network.
If you reset the USERFCMTU option, you can use a larger MTU size that matches the type of physical LAN in use. As the system is originally shipped, the connecting medium and MTU value is an Ethernet cable with an MTU value of 1496 bytes.
To set the USERFCMTU option, enter the following OI command:
NW TCPIP OPTION + USERFCMTU
To reset (clear) the USERFCMTU option, enter the following OI command:
NW TCPIP OPTION - USERFCMTU Note:
1. You can also use the NAU to define the USERFCMTU option during the MCP network configuration process. This function was described in the “Configuring with the NAU” paragraph earlier in this section.
2. The USERFCMTU applies only to IPv4. IPv6 uses PathMTU to address the MTU size question. Refer to the TCP/IP Implementation and Operations Guide for information on PMTU Verification Interval.
Viewing the RESET Reports
The TCP/IP software in the MCP environment enters RESET reports in a table
whenever remotely initiated RESET actions are received. To view this table, enter the following command:
NW TCPIP DISPLAY TABLE RESETRPTS
Your ClearPath MCP server is preconfigured with LAN connectivity, enabling all ClearPath components to communicate with each other as needed.
You can run the system in this standalone configuration as long as you want.
However, if you want to integrate your ClearPath server into a larger network, you must plan and configure several aspects of the system to meet your needs.
This section describes various configuration procedures that are basically common to all server models. They include:
• Integrating your server with an existing BNA network
• Integrating your server with Microsoft networks
• Optimizing MCP networking