Chapter 10 - Managing Routing Through VINES
This chapter describes the Managing Routing through VINES Networks option. This option allows you to create configuration entries for servers equipped with the TCP/IP Routing option. These entries associate the names or serial numbers of servers and their IP addresses.
Through the Managing Routing through VINES Networks option, you can perform the following tasks:
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Enter server configuration information: the names, serial numbers and IP addresses of other VINES servers in your network that have the TCP/IP Routing Option installed. ![]()
Manually establish, modify, and delete specific routes to networks or hosts. ![]()
Establish automatic connectivity, allowing your server to automatically establish a route to any server that sends it an IP packet, and disable automatic connectivity when appropriate. ![]()
Monitor the status of routes between your server and other servers in your network that have the TCP/IP Routing option installed.
When you specify other servers running the TCP/IP Routing option, observe the following guidelines:
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Distinguish between servers accessible through VINES and those accessible only through IP. Servers accessible through VINES can be configured through the Manage Routing through VINES Networks menu, as explained later in this chapter. Servers accessible only through an IP backbone should be configured through the Manage Server-to-Server Connections menu (refer to Chapter 11). ![]()
When adding entries to the TCP/IP configuration, be sure to have a completed TCP/IP Server Information Worksheet on hand. Chapter 6 provides information. ![]()
Carefully consider any modifications to server entries. See Chapter 2 and the planning chapters (Chapter 4, Chapter 5, and Chapter 6) if you need information.
Throughout this chapter, information on the sample TCP/IP Server Information Worksheet from Chapter 6, and the sample Routing Information Worksheet from Chapter 5, is used in examples. These worksheets are repeated in Figure 10-1, Figure 10-2, and Figure 10-3.
Accessing VINES Routing Functions
The Manage Routing through VINES Networks menu allows you to specify other servers equipped with the TCP/IP Routing option. The process involves mapping the IP addresses of servers to their names or serial numbers. To display this menu, choose Manage Routing through VINES Networks from the TCP/IP Main menu.
The Manage Routing through VINES Networks menu lists all the entries for VINES servers in the TCP/IP configuration. The screen indicates how many servers have been included in the configuration.
The following information appears for each entry:
Server - For entries that were added by specifying the server name, this field displays that name. For example, Server 1 and Server 2 were specified by name. For entries that were added by specifying the serial number, a question mark (?) appears until the name of the server is learned.
Serial number - The server's serial number.
IP address - The server's IP address.
Subnetwork mask - The subnetwork mask that was specified for the server's IP address.
Status - The status of the server entry, either ENABLED or DISABLED.
The functions you can perform from the Manage Routing through VINES Networks menu are described in the sections that follow.
This section includes information on the following topics:
When you add an entry for a server, specify either its name or its serial number, and its IP address.
You can specify a server by name if it has already communicated successfully with your server. Typically, servers that meet this requirement can communicate with your server without routing data through foreign host gateways. The TCP/IP configuration program lets you choose the names of these servers from a list. Your server already knows their serial numbers, unless the servers are not currently in operation.
A server must be specified by serial number if:
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It has been down for 96 hours or more. ![]()
It is not yet connected to the VINES network. Note: Servers specified in the Manage Server-to-Server Connections menu will not appear in the Manage Routing through VINES Networks menu. A server can be configured to encapsulate VINES traffic in a TCP/IP packet, or to encapsulate TCP/IP traffic in a VINES packet. However, a VINES server cannot be configured to do both types of encapsulation at the same time.
You should complete a TCP/IP Server Information Worksheet before you add server entries. See Chapter 6 for more information.
To add an entry, follow these steps:
1. At the Manage Routing through VINES Networks menu, choose ADD a Server Entry.
2. The next menu displays a list of all the servers that your server already knows about. This screen is shown below. If the server you want is on the list, choose it. If not, press F2 so you can specify the server's serial number and IP address.
3. If you selected a server from the list, you are prompted for the server's IP address.
If you pressed F2, you are prompted for the server's serial number and IP address. Using the sample worksheet in Figure 10-1, you would specify 112334 for Server 1's serial number and 140.122.2.1 for its IP address.
4. The next screen prompts you for the subnetwork mask for the IP address. Specify the default by pressing Enter if the IP address is not subnetted. Using the sample worksheet, you would specify 255.255.255.0 as the mask for Server 2's IP address.
When you have completed all steps, the Manage Routing through TCP/IP Networks menu appears. It displays the server you added, as well as entries that were added previously.
Before you modify any of the parameters that make up a server entry, carefully consider whether your changes will adversely affect communications between your server and other servers. For example, changing the IP address of another server may make all foreign hosts accessible through that server unreachable.
When you modify a server entry, the configuration program steps you through the same series of screens that were used to add the entry. Perform the following steps:
1. At the Manage Routing through VINES Networks menu, choose MODIFY a Server Entry.
2. Choose the entry you wish to modify. Display the screens that contain server information, and modify the information accordingly. See the preceding section, "Adding a Server Entry," for information on these screens.
3. When you have finished modifying information, return to the Manage Routing through VINES Networks menu, which shows the new information you entered for the server.
To delete a server entry, perform the steps that follow.
Caution: Deleting a server entry may make the foreign hosts you access through that server unreachable. All routes through a deleted server are deleted by the system. Be particularly careful if the server you are deleting is being used as the default gateway.
1. At the Manage Routing through VINES Networks menu, choose DELETE a Server Entry.
2. Choose the entry you wish to delete.
3. The configuration program prompts you for confirmation. Specify YES to delete the entry, or NO to cancel the deletion. YES is the default.
Enabling and Disabling a Server Entry
To enable or disable a server entry, perform the steps that follow.
Caution: Disabling a server entry may make the foreign hosts you access through that server unreachable. All routes through a disabled server are marked NOT in use by the system.
1. At the Manage Routing through VINES Networks menu, choose ENABLE/DISABLE a Server Entry.
2. Choose the entry you wish to enable or disable.
3. The configuration program prompts you for confirmation. Specify YES to continue, or NO to cancel the operation. YES is the default.
Enabling and Disabling Automatic Connectivity
If you enable automatic connectivity, your server will establish a route to any server that specifies your server in its TCP/IP configuration and routes IP traffic through your server. Disabling automatic connectivity removes any automatically configured server entries as well as any routes using these servers as gateways.
To enable or disable automatic connectivity, follow these steps:
1. At the Manage Routing through VINES Networks menu, choose ENABLE/DISABLE Automatic Connectivity.
2. The configuration program prompts you for confirmation. Specify YES to complete the operation, or NO to cancel the operation. YES is the default.
Specific-Route Configuration Tasks
This section explains how to manage specific routes through VINES server gateways. Topics discussed include:
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Adding a Route ![]()
Modifying a Route ![]()
Deleting a Route
Before you modify or delete a specific route, carefully consider whether your action will adversely affect your server's routing capability. For example, modifying or deleting a route could prevent your server from reaching certain destinations.
The functions explained here allow you to establish and manage specific routes through a VINES server gateway. This differs from the Manage Specific Routes function under the Manage Routing through TCP/IP Networks menu, in that the routes established from this menu send an IP packet encapsulated in a VINES packet to the VINES server gateway. The VINES server gateway then strips off the VINES encapsulation and routes the IP packet to its destination. (In contrast, specific routes established from the Manage Routing through TCP/IP Networks menu send raw IP packets to the designated gateway. This gateway then routes the IP packets to their destination.)
To access the Manage Specific Routes menu, choose MANAGE Specific Routes from the Manage Routing through VINES Networks menu.
The Manage Specific Routes menu lists all the manually created route entries associated with a specific VINES server. You can route to a host, to a network, or to a subnetwork.
The following fields appear for each entry:
Dest type - The type of destination. The destination type can be network (which includes subnetworks) or host.
Dest IP address - The IP address of the destination.
Subnetwork mask - The subnetwork mask for the destination IP address. If the destination is a host, no subnetwork mask appears.
Status - The route's status, either in use (the route can be used), or NOT in use (the route is unusable).
The functions available at the Manage Specific Routes menu are described in the sections that follow.
You can add a route to a network or subnetwork, or a host. This section explains both procedures. You should complete a TCP/IP Server Information Worksheet and a Routing Information Worksheet before performing these procedures.
Adding a Route to a Network or Subnetwork
To add a route to a network or subnetwork, perform the following steps:
1. At the Manage Specific Routes menu, choose ADD a Route.
2. The configuration program asks if the destination you want to specify is a host. Specify NO. (This is the default.)
3. At the Specify Destination IP Address Screen, enter the IP address of the destination network or subnetwork. Using the sample worksheet in Figure 10-2, you would specify 147.190 as the destination network.
4. At the Specify Subnetwork Mask screen, enter the subnetwork mask if the destination is a subnetwork. Use the default if the destination is a non-subnetted network - for example, 255.255.0.0 for 147.190.
5. The configuration program asks if you want to reach any more destinations through the gateway you specified. In our example, the configuration program would ask if you want to reach any more destinations through Server 1.
If you answer YES, the Specify Destination IP Address screen appears, enabling you to specify another destination that can be reached through the gateway. If you answer NO, the program returns to the Manage Specific Routes menu.
Adding a Route to a Host
Adding a route to a host is similar to adding a route to a network or subnetwork. Perform the following steps:
1. At the Manage Specific Routes menu, choose ADD a Route.
2. The configuration program asks if the destination you want to specify is a host. Specify YES.
3. At the Specify Destination IP Address screen, enter the IP address of the destination host that can be reached through the specified gateway.
4. The configuration program asks if you want to reach any more destinations through the server gateway you specified. If you answer YES, the Specify Destination IP Address screen appears, allowing you to specify another destination that can be reached through the gateway. Follow the steps in this procedure, beginning at step 3, to add another entry. If you answer NO, the program returns to the Manage Specific Routes menu.
When you have completed all steps, the Manage Specific Routes menu displays the entry you just created, as well as entries that were added previously.
To modify a route, perform the following steps:
1. At the Manage Specific Routes Menu, choose MODIFY a Route.
2. Choose the route entry you want to modify. You then can proceed to display the screens that contain information specified when the route was added. The preceding section, "Adding a Route," provides information on these screens.
To delete a route, perform the following steps:
1. At the Manage Specific Routes menu, choose DELETE a Route.
2. Select the route you wish to delete.
3. The configuration program prompts you for confirmation. Specify YES to delete the entry, or NO to cancel the deletion. YES is the default.
Monitoring Routes Through the VINES Interface
The Manage Routing through VINES Networks menu offers two options that allow you to monitor the status of routes between your server and others in your network that have the TCP/IP Routing option installed:
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Display System Routes ![]()
Display Status of Server Gateways
At the end of this section is a discussion of how automatically generated connections are displayed on these screens.
When you choose the Display System Routes option from the Manage Routing through VINES Networks menu, the screen below appears. This screen displays all routes configured through the VINES interface, and the status of those routes.
The following information appears for each entry:
Gateway - The name of the VINES server through which you are routing packets. If the server has not communicated in the last 96 hours, the serial number of the server appears in this field.
Dest Type - This field provides information on both the kind of destination that can be reached by way of the route and the type of route. Destination can be one of the following:
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network - A network or subnetwork. ![]()
host - A host. ![]()
direct - An adjacent network or subnetwork. ![]()
default - All destinations that can be reached through the default gateway, including networks, subnetworks, and hosts. The default gateway is used when no other routes in use provide a gateway to a destination. The default gateway is displayed as long as it can be accessed through either VINES or IP. Dest IP Address - The IP address of the destination network, subnetwork, or host.
Pkts Fwd - The number of packets forwarded to the destination that can be reached by way of this route.
Sts - The route's status, either UP (the route can be used) or DOWN (the route is unusable).
Flags - Can be any of the following:
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Manual - The route was manually defined. ![]()
Dyn - The route was created using information from an ICMP redirect packet. ![]()
Auto - The configuration program defined the route using the IP address assigned to a VINES server configured to route IP traffic through VINES. ![]()
Mod - A route that was created manually or was dynamically updated based on information from an ICMP redirect packet.
Displaying the Status of Server Gateways
This option shows a list of servers that you configured through the Manage Routing through VINES Networks menu, and the status of the routes to those servers.
The following information appears for each entry:
Server - The name of the VINES server through which you are routing packets. An asterisk beside the name indicates that the server was dynamically configured through automatic connectivity. If the name of the server has not yet been determined, a question mark (?) appears.
Serial no. - The serial number of the VINES server through which you are routing packets.
IP address - The IP address of the VINES server through which you are routing packets. At times, the server name and the IP address may not correspond. See the next section, "Automatically Generated Connections," for more information.
Subnetwork Mask - The subnetwork mask of the VINES server through which you are routing packets.
Flags - The flags field shows the status of the route between your server and the server identified by the entry. When more than one flag is set, the values are added together. The flags field is eight bits wide. All values are displayed in hexadecimal. The possible values for the flags are shown in Table 10-1.
Automatically Generated Connections
If automatic connectivity is enabled, entries are created on the Display Status of Server Gateways screen whenever another server routes packets through your server.
For example, Figure 10-4 shows a small network. Server 1 routes a packet from the PC/TCP workstation through Server 2 and Server 3 to the TCP/IP Host.
When Server 1 sends the packet to Server 2, the packet contains:
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The IP source address of the PC/TCP workstation (135.100.136.4) ![]()
The destination address of the foreign host (135.100.132.1)
Server 2 receives the packet from Server 1, and forwards it to Server 3, encapsulated in a VINES packet. The packet now contains:
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The VINES IP source address (server serial number) of Server 2. ![]()
The VINES IP destination address (server serial number) of Server 3.
The TCP/IP packet remains intact.
Server 3 receives the packet and creates a host route to Server 1. On the Display Status of Server Gateways screen, the entry looks like this:
The asterisk indicates that the entry is automatically configured. There are several things to notice about this entry:
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The server name is the name of the VINES server gateway, Server 2, and does not correspond to the IP address, which belongs to the PC/TCP workstation. ![]()
The Flags setting of 13 (hexadecimal 0x1+0x2+0x10) indicates that the connection is up, the connection is the result of automatic connectivity, and a reverse ARP (RARP) transaction is pending. ![]()
The RARP transaction means that Server 3 sends an ARP request to Server 2. This request contains the physical address of the VINES server gateway. If the RARP is successful, Server 3 receives the IP address of Server 2. This allows Server 3 to create a route to the network on which Server 1 resides. The Display Status of Server Gateways screen will then look like this:
The Flags setting of 7 (hexadecimal 0x1+0x2+0x4) in this screen indicates that the connection is up, the connection was created through automatic connectivity, and the listed route is a network route. If the reverse ARP transaction is unsuccessful, the entry shown in the previous screen (Flags = 13) remains.
The routes created are shown in the following table.