Chapter 6 - Configuring Server Support for Banyan IP Clients
This chapter describes how to configure servers to provide IP support for Windows 95 and Windows NT clients. Configuring servers for IP support is only necessary if your Banyan Clients use IP as their network protocol.
This chapter covers:
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Network requirements for IP support |
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Configuring servers for IP support |
Network Requirements for IP Support
To provide IP routing support for Banyan Clients with IP, you must have at least one server in your network running VINES 6.20 (0) or greater or StreetTalk for Windows NT.
In addition, if you have disabled VINES IP (VIP) on the servers on a segment and are running TCP/IP only on that segment, you need to install the Banyan TCP/IP Server-to-Server option on the VINES servers that act as IP routing servers.
If you are running VINES IP in addition to TCP/IP (referred to as LAN/IP on the server console) on your servers, you do not need the Banyan TCP/IP Server-to-Server option installed on those servers providing IP routing support to Banyan IP Clients.
To support clients connecting through a PPP dialup, you do not need to install any of Banyan's IP Routing options.
The following table summarizes the option requirements:
| If Your Network Has: | Your IP Routing Servers Must Run: |
| VINES IP and TCP/IP enabled on the servers on a segment |
VINES 6.20 or greater or StreetTalk for Windows
NT No options required |
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TCP/IP only enabled on the servers on a segment (VINES IP is disabled on the segment) |
VINES 6.20 or greater or StreetTalk for Windows
NT TCP/IP Server-to-Server option |
| Clients connecting through a PPP dialup |
VINES 6.20 or greater or StreetTalk for Windows
NT No options required |
Note: The DOS and Windows 3.x IP clients still require Banyan's TCP/IP Server-to-Server option. See Installing Banyan IP Clients for DOS and Windows 3.1 for information on server support for these clients.
Creating Server-to-Server Connections from an IP Routing Server
Because an IP routing server can also communicate using Server-to-Server TCP/IP, you can force a TCP/IP connection between an IP routing server and any server in which the Server-to-Server option is installed. However, if you choose to create a Server-to-Server connection, you need to modify the default metric for the connection. The default metric for Server-to-Server TCP/IP connections is 25. This is higher than the default metric for LAN IP, which is equal to the media plus 1 for IP encapsulation or plus 2 for UDP encapsulation.
Refer to Chapter 11 of the Banyan TCP/IP Guide for information on configuring IP connections from the server console. When assigning the metric, use the value for the media that connects the two servers. For example, assign a metric of 2 to the interface on servers that are connected to a 10 Mbps Ethernet link.
Configuring Servers for IP Support
For each IP Routing server, you need to modify these settings to support IP communications:
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Change the size of the Sequenced Packet Protocol/Interprocess Communication (SPP/IPC) Reliable Maximum Transfer Unit (MTU). |
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Enable LAN IP (LAN IP refers to the TCP/IP protocol). |
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Specify the encapsulation type. |
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Disable VINES IP on individual interfaces. You modify each of these settings from the server console. |
Changing the Size of the SPP/IPC Reliable Maximum Transfer Unit (MTU)
The SPP/IPC Reliable MTU size is the maximum size allocated for the SPP data in a packet. The default (and maximum) SPP/IPC Reliable MTU size is 1450 bytes. However, because packets processed by Banyan IP Clients require additional space for IP and UDP header information, you must reduce the size of the MTU on an IP Routing server.
On VINES networks that use no encapsulation, the packet header is approximately 50 bytes. Thus, an Ethernet packet of maximum size (just over 1500 bytes) can transport a VINES packet header and a data packet up to the size of the MTU.
However, after you install the Banyan IP Client, the encapsulating protocol, in this case UDP, increases the size of each VINES packet it handles by adding its own header. Since you cannot increase the size of the Ethernet packet, adding the new header results in fewer bytes being available in the packet to carry data. The data contained in the original VINES packet can no longer fit within a single encapsulated packet. As a result the original VINES packet becomes fragmented into separate packets: one carrying the maximum amount of data, and one carrying the overflow.
Fragmenting and subsequently reassembling the IP or UDP packets slows performance, particularly during file transfers.
You can prevent fragmentation by reducing the size of the SPP/IPC Reliable MTU. When you reduce the SPP/IPC Reliable MTU size, all SPP/IPC Reliable connections to the server use the reduced MTU size. Use the recommended MTU size for any server that a Banyan IP Client workstation makes an SPP connection to, regardless of whether the TCP/IP option is installed on that server.
It is recommended that you change this value for any server that will be part of an SPP/IPC Reliable connection with a Banyan IP Client workstation, whether that server has a TCP/IP option or not. If the TCP/IP encapsulation type is set to both IP and UDP, or UDP only, the recommended value is 1436. If it is set to IP only, the recommended value is 1440. For information on IP and UDP encapsulation, see "Specifying the Encapsulation Type" later in this chapter.
To Modify the SPP/IPC Reliable MTU Size
1. At the server console, display the Operator Menu.
2. Select Manage Communications. The Manage Communications menu appears.
3. Select VINES/IP. The Manage VINES/IP Interface menu appears. This menu displays the slot number and type of each interface installed on the server and indicates whether VINES IP is enabled or disabled for that interface.
4. Select CHANGE SPP MTU SIZE. The Change MTU Size for SPP Connections screen appears. The existing SPP/IPC Reliable MTU size appears at the top of the screen.
5. Enter the new size for the SPP/IPC Reliable MTU.
You must enable LAN/IP on a server that will act as a routing server for a Banyan IP Client workstation. After you enable LAN/IP on the server, it can exchange IP packets with other IP servers throughout the network.
If LAN/IP is disabled on a server, you need to manually enter at the console the IP address of other servers targeted as IP connections.
To Enable LAN IP
1. At the server console, display the Operator Menu.
2. Select Manage Communications. The Manage Communications menu appears.
3. Select VINES/IP. The Manage VINES/IP Interface menu appears. This menu indicates whether LAN/IP is currently enabled or disabled on the server.
4. Do one of the following:
- If LAN/IP is already enabled, you do not need to change the current setting. Skip to "Specifying the Encapsulation Type," which follows.
- If LAN/IP is currently disabled, select MANAGE LAN/IP. The Manage LAN/IP menu appears.
5. Select Enable/disable LAN/IP. The Enable/Disable LAN/IP on the server screen appears, and you are prompted to confirm the current LAN/IP setting.
6. Select YES. LAN IP becomes enabled on the server.
You are now ready to specify the encapsulation type for the server.
Specifying the Encapsulation Type
In communicating with a Banyan IP Client, the IP routing server encapsulates VINES IP packets within one of the following types of packets:
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UDP |
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IP |
The packet type used depends on the type of Banyan IP Client workstation communicating with the server. Workstations running DOS or Windows 3.x use IP encapsulation. Workstations running Windows 95 or Windows NT use UDP encapsulation.
You can specify which type of encapsulation the server can perform.
Note: Enabling encapsulation on the server consumes some of the resources required to maintain server-to-server connections. To avoid limiting the number of connections that the server can maintain with other servers, enable only the form of encapsulation that you need. For example, if the server needs to communicate with Banyan IP Client workstations running on Windows 95 or Windows NT, but not with workstations running other versions of IP Client, enable UDP encapsulation only.
Enable both types of encapsulation only if the server needs to communicate with both workstation types.
If you disable both types of encapsulation, you automatically disable LAN IP.
To Specify the Type of Encapsulation Used by the Server
1. At the server console, display the Operator menu.
2. Select Manage Communications. The Manage Communications menu appears.
3. Select VINES/IP. The Manage VINES/IP Interface menu appears. This menu indicates whether LAN/IP is enabled or disabled on the server and the type of encapsulation that the server currently supports.
4. Select MANAGE LAN/IP. The Manage LAN/IP menu appears.
5. Select Specify encapsulation type(s). The Specify Encapsulation Type(s) screen appears.
6. For each of the two types of encapsulation (IP and UDP), do one of the following:
- Enter Y to enable this type of encapsulation.
- Enter N to disable this type of encapsulation.
7. Press F10 to save the changes.
You are now ready to disable VINES IP on the server.
Disable VINES IP on any interface to prevent the server from transmitting VINES IP packets on the network. Disabling VINES IP is useful for those environments where you only want one type of network packet transmitted on a LAN segment. You do not need to disable VINES IP to use IP Client; both VINES IP and IP can coexist in the same network.
Disabling VINES IP on an interface has no effect on other protocols, such as AppleTalk, that are used on the segment.
Note: If any server on the LAN segment transmits VINES IP packets, it is recommended that you do not disable VINES IP for IP Routing servers on that segment. Since a VINES server on the segment uses VINES IP to communicate, these VINES IP packets continue to exist on the segment regardless of whether you disable VINES IP on your IP Router. In addition, IP Routing servers on the segment need to use VINES IP to communicate with VINES servers that exist on their segment. See "Disabling VINES IP on LAN Segments with Multiple Servers" later in this section for more information.
To Disable VINES IP over an Interface
1. At the server console, display the Operator Menu.
2. Select Manage Communications. The Manage Communications menu appears.
3. Select VINES/IP. The Manage VINES/IP Interfaces menu appears. This menu displays the slot number and type of each interface installed on the server, indicates whether VINES IP is enabled or disabled for that interface, and displays the metric for that interface.
4. Do one of the following:
- If you do not need to change the current settings for any interface, skip to step 8.
- To change the current setting for an interface, select Manage Network Interface. The cursor appears beside the first interface listed at the bottom of the screen.
5. Select the interface to disable. You can select only one interface at a time.
6. Press ENTER. The Manage Network Interface screen appears and you are prompted to confirm the current VINES/IP setting.
7. Select YES to change the current setting. The current VINES IP setting is changed for the selected interface.
8. To activate all of the server configuration changes, shut down the server software and reboot the server.
Disabling VINES IP on LAN Segments with Multiple Servers
IP Client servers on which you disable VINES IP may experience problems communicating with other servers. You may need to modify the server configuration of the IP Client server to allow servers to communicate properly.
In general, within a given segment, if at least one server uses VINES IP only, do not disable VINES IP on the IP routing servers that need to communicate with that server. Only disable VINES IP if you want to completely eliminate VINES IP packets from the segment. Servers can communicate only when they recognize the same communications protocol. When a server, such as an IP routing server, is configured to use multiple protocols, it has multiple options for communicating with another server.
When establishing a connection, the server always chooses the common route with the lowest metric. VINES IP, which uses the metric for the LAN media, is usually the route with the lowest metric cost.
When VINES IP is enabled on an IP routing server, that server can communicate with other VINES servers. However, disabling VINES IP on the IP routing server, forces the server to communicate using LAN/IP. Communication problems occur when the IP routing server attempts to establish a LAN/IP connection with another server that is not an IP routing server (and, therefore, does not use LAN/IP). The LAN/IP connection established between the two servers will be non-functional and the servers cannot communicate.
