Chapter 9 - Interfaces to Non-VINES Protocols
This chapter describes interfaces between VINES and the following protocol families:
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TCP/IP ![]()
IPX/SPX ![]()
AppleTalk ![]()
SNA
The chapter does not discuss gateways, such as the Banyan SMTP or 3270/SNA gateways. Instead, it focuses on interfaces between low-level VINES protocols such as VINES IP and non-VINES protocols.
This section describes interfaces between VINES and the TCP/IP protocol family. The section describes these interfaces in the following contexts:
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TCP/IP Server-to-Server ![]()
TCP/IP Routing
The Banyan TCP/IP Server-to-Server option allows VINES and ENS servers to tunnel VINES traffic through TCP/IP networks. On ENS for UNIX servers, the Server-to-Server IP option provides the same capability.
Servers that tunnel VINES traffic through TCP/IP networks have an internal interface between VINES IP and IP. This interface allows these servers to encapsulate VINES IP packets with an IP header.
Note: The TCP/IP protocol type assigned to VINES is 83 (decimal).
Figure 9-1 shows two VINES servers equipped with the TCP/IP Server-to-Server option tunneling VINES traffic through a TCP/IP network.
In the VINES neighbor table and network table, entries for VINES neighbors on TCP/IP networks and routes through these networks are created. See Chapter 4 and Chapter 5 for more information.
The Banyan TCP/IP Routing option allows VINES and ENS servers to acts as IP routers. In addition to routing IP packets as a normal IP router, these servers can route IP traffic through VINES networks as follows:
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Tunnel IP packets between a TCP/IP host and a workstation that runs the VINES Transport version of PC/TCP ![]()
Tunnel IP packets between TCP/IP networks through VINES networks
VINES Transport Version of PC/TCP
For workstations running the VINES Transport version of PC/TCP, one server equipped with the routing option provides routing services in most cases. Figure 9-2 shows a VINES network that has PC/TCP.
When a workstation running the VINES Transport version of PC/TCP sends an IP packet, it is encapsulated within two VINES headers:
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VINES IP header ![]()
VINES IPC short header, which follows the VINES IP header
When the packet reaches a server with the TCP/IP Routing option, the VINES IP and IPC headers are removed so that the IP packet can be routed through foreign host gateways. By the same token, when a server that has the TCP/IP Routing option routes an IP packet from a foreign host to the workstation, the server encapsulates the IP packet in the VINES IP and IPC short headers.
The VINES Transport version of PC/TCP uses two VINES well-known ports:
0x14 - PC/TCP uses this port to send and receive TCP/IP traffic through the VINES network. This value is used as both the source and destination port number in the short IPC header.
0x15 - PC/TCP uses this port to exchange TCP/IP Address Resolution Protocol (ARP) traffic with the server. This value is used as both the source and destination port number in the short IPC header. The ARP header is encapsulated by VINES IP and IPC short headers.
Tunneling TCP/IP Traffic Through VINES Networks
Servers that tunnel IP traffic through VINES networks have an internal interface between VINES IP and VINES IPC, and IP.
When an IP packet passes through two or more VINES servers to its destination, the IP packet is encapsulated within two VINES headers:
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VINES IP header, which follows the IP header ![]()
VINES IPC short header, which follows the VINES IP header
VINES IPC uses the well-known port, 0x14, to tunnel traffic.
VINES handles the routing for all VINES IP and IP packets that travel between VINES servers. Figure 9-3 shows two foreign hosts tunneling TCP/IP traffic through a VINES network
Figure 9-3 illustrates the following process:
1. The packet leaves Foreign Host 1 as an IP packet.
2. When the packet arrives at Server 1, the IP packet is encapsulated in a VINES IP packet (that is, a VINES IP header and a VINES IPC header is added).
3. The packet is routed through VINES to Server 2.
4. When the packet arrives at Server 2, the VINES IP header is stripped off.
5. The packet is routed to its destination via IP.
While encapsulated in VINES IP packets, the IP packets are routed from server to server just like normal VINES packets. When the IP packet reaches a server that must route it to a foreign host or gateway, VINES IP software unencapsulates the packet (strips off the VINES headers), and passes it to IP software. Once unencapsulated, the packet becomes a standard IP packet.
ENS servers and VINES servers equipped with the ENS for NetWare option provide an interface between VINES and IPX/SPX protocols. This interface allows these servers to tunnel VINES traffic through NetWare networks and tunnel NetWare traffic through VINES networks.
Tunneling VINES Traffic Through NetWare Networks
Servers that tunnel VINES traffic through NetWare networks have an internal interface between VINES IP and IPX. This interface allows these servers to encapsulate VINES IP packets with an IPX header.
Figure 9-4 shows VINES servers tunneling VINES traffic through a NetWare network.
In Figure 9-4, a VINES server, Server 3, wants to communicate with a VINES workstation, Workstation 1. Along the route between Server 3 and Workstation 1, there is a server, Server 2, that acts as a gateway to a NetWare network. Server 3 and the workstation communicate as follows:
1. Server 3 passes VINES packets to Server 2.
2. Before Server 2 passes packets to the NetWare file server that acts as the gateway to the NetWare network, it surrounds the packets in IPX protocol headers.
3. When Server 1 receives the packets, it strips off the IPX protocol headers so that Workstation 1 can interpret the packets.
In the VINES neighbor table and network table, entries for VINES neighbors on NetWare networks and routes through these networks are created. See Chapter 4 and Chapter 5 for more information.
Tunneling NetWare Traffic Through VINES Networks
Servers that tunnel NetWare traffic through VINES networks have an internal interface between VINES IP and VINES IPC, and IPX. These servers encapsulate the IPX header in two VINES headers:
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VINES IP header ![]()
VINES IPC short header, which follows the VINES IP header
Figure 9-5 shows a NetWare tunnel through a VINES network.
In Figure 9-5, NetWare File Server 1 wants to communicate with NetWare File Server 2. Between the two file servers are two ENS servers and a VINES network connecting the two ENS servers. The two file servers communicate as follows:
1. When ENS Server 1 passes packets to ENS Server 2, ENS Server 1 encapsulates the packets in VINES IP and short IPC protocol headers for transmission through the VINES network.
2. When the packets reach ENS Server 2, ENS Server 2 removes the VINES IP and short IPC headers so that the packets can be forwarded to NetWare File Server 2.
VINES and ENS servers use the VINES well-known port 0x21. This value is used as both the source and destination port number in the short IPC header of encapsulated IPX packets.
Servers equipped with the VINES for Macintosh option can tunnel AppleTalk traffic through VINES networks. These servers have an internal interface between VINES IP and IPC, and the AppleTalk Datagram Delivery Protocol (DDP). These servers encapsulate the DDP header in two VINES headers:
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VINES IP header ![]()
VINES IPC short header, which follows the VINES IP header
Figure 9-6 illustrates the tunneling of AppleTalk traffic through a VINES network.
In Figure 9-6, the same technique for moving TCP/IP and NetWare traffic through VINES networks is also used for moving AppleTalk traffic through VINES networks. See "Tunneling TCP/IP Traffic Through VINES Networks" and "Tunneling NetWare Traffic through VINES Networks" earlier in this chapter for more information.
VINES servers use the VINES well-known port 0x1F to tunnel AppleTalk traffic. This value is used as both the source and destination port number in the short IPC header of encapsulated AppleTalk packets.
The AppleTalk routing table on VINES servers contains special entries for other VINES servers on AppleTalk networks. The number of AppleTalk hops to reach an AppleTalk network through a network of VINES servers depends on the number of tunnels configured. A single tunnel counts as 2 AppleTalk hops.
The Banyan Server-to-Server over SNA (SS/SNA) option allows VINES traffic to be tunneled through IBM SNA networks using IBM SNA Advanced Program-to-Program Communication (APPC) protocol headers appended to the VINES IP header in VINES packets. The option is installed on both servers and dedicated workstation gateways on each VINES network. The Banyan SS/SNA option supports both SDLC and Token-Ring interfaces into SNA environments.
The SS/SNA service on the server initiates an SPP connection with the workstation software that encapsulates VINES traffic for transit through the SNA network, as follows:
1. VINES packets are sent from the server to the gateway where headers are appended.
2. On reaching the destination:
- The headers are stripped.
- The packet is routed in the VINES network.
Figure 9-7 shows this process.
In the VINES neighbor table and network table, entries for VINES neighbors on SNA networks and routes through these networks are created. See Chapter 4 and Chapter 5 for more information.