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AIS V3.3 Protocol Config Ref Vol 2

Using VINES

This chapter describes the commands to configure the Banyan VINES protocol and includes the following sections:

Note:If you need more detailed information on VINES Protocols, consult the Banyan publication: VINES Protocol Definition, order number: 003673

VINES Overview

VINES Over Router Protocols and Interfaces

The VINES protocol routes VINES packets over the following interfaces and protocols:

It also supports packets across an 802.5 Source Routing Bridge (SRB).

The VINES protocol is implemented at the network layer (layer 3) of the OSI model. VINES routes packets from the transport layer in one node to the transport layer in another node. As VINES routes the packets to their destination nodes, the packets pass through the network layers of the intermediate nodes where they are checked for bit errors. A VINES IP packet can contain up to 1500 bytes including the network layer header and all higher layer protocol headers and data.

Service and Client Nodes

The VINES network consists of service nodes and client nodes. A service node provides address resolution and routing services to the client nodes. A client node is a physical neighbor on the VINES network. All routers are service nodes. A Banyan node can be a service node or client node.

Each service node has a 32-bit network address and a 16-bit subnetwork address. The IBM 2212 has a configurable network address. This address identifies the router as a service network node for Vines. Banyan has assigned the range30800000 to 309FFFFF to IBM for use in its routers. This router uses the range 30900000 to 3097FFFF.
Note:It is extremely important that no two routers be assigned the same network address. The network address for a Banyan service node is the 32-bit hexadecimal serial number of the service node. The subnetwork address for all service nodes is 1.

The network address for each client node is generally the network address of the service node on the same network. However, if a client node is on a LAN that has more than one service node, it is assigned the network address of the service node that responds first to the client node's address assignment request. The subnetwork address for each client node is a hexadecimal value of 8000 to FFFE.

VINES Network Layer Protocols

This implementation of VINES consists of the following four network layer protocols. The next sections describe these protocols and their implementations.

VINES Internet Protocol (VINES IP)

The VINES IP protocol routes packets through the network using the destination network number in the VINES IP header. VINES IP consists of an 18-byte network layer header which prefixes each packet. Table 51 summarizes the fields within this header.

VINES IP Implementation

When VINES IP receives a packet, it checks the packet for size and exception errors. A size error is a packet that is less than 18 bytes or greater than 1500 bytes. If it contains a size error, VINES IP discards the packet. An exception error is, for example, a bad checksum or a hop count that has expired.

If the packet does not contain size or exception errors, VINES IP checks the destination address and forwards the packet as follows:


Table 51. Vines IP Header Fields Summary
VINES IP Header Field # of Bytes Description
Checksum 2 Detects bit-error corruption of a packet.
Packet Length 2 Indicates the number of bytes in the packet including the VINES IP header and data.
Transport Control 1 Consists of the following five subfields:

Class
Determines the type of nodes to which VINES IP broadcast packets are sent.

Error
If the error bit is set, an exception notification packet is sent to the transport layer protocol entity when a packet cannot be routed to a service or client node.

Metric
Requests that the service node of the destination client node return to the source a routing cost from the service node to the destination client node.

Redirect
Indicates whether the packet contains an RTP message specifying a better route to use.

Hop Count
Specifies the range a packet can travel. The hop count can range from 0x0 to 0xf.
Protocol Type 1 Specifies the VINES network layer protocol of the packet as VINES IP, RTP, ICP, or VINES ARP.
Destination Network Number 4 A 4-byte network number in the VINES IP address of the destination.
Destination Subnetwork Number 2 A 2-byte subnetwork number in the VINES IP address of the destination.
Source Network Number 4 A 4-byte network number in the VINES IP address of the source.
Source Subnetwork Number 2 A 2-byte subnetwork number in the VINES IP address of the source.

Routing Update Protocol (RTP)

RTP gathers and distributes routing information that VINES IP uses to compute routes throughout the network. RTP enables each router to periodically broadcast routing tables to all of its neighbors. The router then determines the destination neighbor it will use to route the packet.

Service nodes maintain two tables: a routing table and a neighbor table. Both of these tables have timers that age their contents to eliminate out-of-date entries. Routing updates for X.25 interfaces occur when there is a change in the routing database, for example, when a node goes up/down or the metric changes.

Routing Table

The routing table contains information about the service nodes. Figure 14 shows a sample routing table. Descriptions of the fields in this table follow the figure.

Figure 14. Sample Routing Table

Net Address  Next Hop Nbr Addr Nbr Intf   Metric   Age (secs)
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
  S  30622222       30622222:0001    Eth/0       20       30
 
  H  0027AA21       0027AA21:0001    Eth/1       2        120
 
  P  0034CC11       0034CC11:0001    X.25/0      45       0
 
  3 Total Routes



S => Entry is suspended, H => Entry is in Hold-down,
P => Entry is permanent

Routing Table Field
Description

Net Address
The Net Address is a unique 32-bit number. An S, H, or P preceding the Net Address field indicates the following:

S
Indicates the service node is in suspended state and is advertised, for 90 seconds, as being down. After 90 seconds, the router removes the entry for this service node from the routing table.

H
Indicates the service node is in hold-down state and is advertised, for 2 minutes, as being down. After 2 minutes, the router advertises the service node as operational. If a service node is in suspended state and it receives an RTP packet, the service node enters the hold-down state.

P
Indicates that the X.25 interface enters permanent state for 4-1/2 minutes after initialization. After 4-1/2 minutes, the neighbor enters the permanent state and its age stays at 0 while in this state. If the X.25 interface goes down, the entry is removed from the routing table.

Next Hop Nbr Addr
The address of the neighbor service node that is the next hop on the least-cost path to the network.

Nbr Intf
The medium to which the next hop neighbor service node is attached.

Metric
An estimated cost, in 200-millisecond increments, to route the VINES packet to the destination service node.

Age (secs)
The current age, in seconds, for the entry. If a router does not receive an update about a service node that is in the routing table at least every 360 seconds (6 minutes), the router removes the entry for that service node from the routing table.

Neighbor Tables

The neighbor table contains information about the neighbor service nodes and client nodes connected to the router. Figure 15 shows a sample neighbor table and descriptions of the fields in this table follow the figure.

Figure 15. Sample Neighbor Table

Nbr Address    Intf   Metric   Age(secs)   H/W Addr RIF
- - - - - - - - - - - - - - - - - - - - - - - - - - - -
 
30633333:0001  TKR/0     4        30     0000C0095012
 
0035CC10:8000  Eth/1     2        120    0000C0078221
 
2 Total Neighbors

Neighbor Table Field
Description

Nbr Address
The address of the neighbor node. In Figure 15, the address 30633333:0001 is a service node and address 0035CC10:8000 is a client node.

Intf
The medium to which the neighbor node is attached.

Metric
An estimated cost, in 200-millisecond increments, to route the VINES packet to the neighbor node.

Age (secs)
The current age, in seconds, for the entry. If a router does not receive a routing update from a neighbor at least every 360 seconds (6 minutes), the router removes the entry for that neighbor from the neighbor table and, if the neighbor is a service node, from the routing table.

H/W Addr
The node's LAN address if the neighbor is connected to a LAN. If the Frame Relay protocol is running, the H/W Addr is the Data Link Connection Identifier (DLCI). For X.25 interfaces, the H/W Addr is the X.25 address of the neighbor.

RIF
Routing Information Field. A sequence of segment and bridge numbers, in hexadecimal, which indicate a path through the network between two stations. RIF is required for source routing.

RTP Implementation

RTP entities issue the following packets:

Unless connected by a permanent circuit, every client and service node broadcasts an RTP update every 90 seconds. This notifies the neighbors of the node's existence and its type (service or client node) and, in the case of service nodes, advertises their routing databases. When a router receives an update packet from a service node, RTP extracts the VINES IP address and looks in the routing table for an existing entry on that service node. If it exists, RTP updates the entry and resets the entry's timer. If an entry does not exist, RTP creates one and initializes the timer for that entry.

Internet Control Protocol (ICP)

ICP generates network information messages on two types of packets destined for the local router:

VINES Address Resolution Protocol (VINES ARP)

The VINES ARP protocol assigns unique VINES IP addresses to the client nodes. VINES ARP includes the following packet types:

To assign a VINES IP address to a client node, VINES ARP implements the following algorithm:

  1. The client node broadcasts a query request packet.

  2. Service nodes respond with a query response packet containing the destination MAC address of the client node and a broadcast VINES IP address.

  3. The client node issues an assignment request packet to a service node that responded with a query response packet.

  4. The service node responds with an assignment response packet that contains the VINES network and subnetwork addresses.

Each client node maintains a timer that has a default setting of two seconds. The timer starts when a client node transmits a query request or assignment request packet. The client node stops and resets the timer when it receives a query response packet. When a timeout period exceeds two seconds, the client node initializes, broadcasts a query request packet, and resets the timer. Table 52 summarizes the states the service and client nodes enter during VINES ARP implementation.

Table 52. Client and Service Node VINES ARP States
Client Node States
 Initialization   The client node is initializing. 
 Query   The client node is transmitting a query request packet. 
 Request   The client node received a query response packet from a service node and is transmitting an assignment request packet to the service node it heard from. 
 Assigned   The client node received an assignment response packet containing the VINES network and subnetwork addresses. 
Service Node States
 Initialization   The VINES ARP protocol is initializing. 
 Listen   The service node is waiting for query request packets from the client nodes. 
 Service   The service node received a query request packet and sent a query response packet. 
 Assignment   The service node issues an assignment response packet containing the VINES network and subnetwork addresses. 

Basic Configuration Procedures

The steps to initially configure each router that sends and receives VINES packets are as follow:

  1. Assign a unique 32-bit hexadecimal address to each router in the VINES network. Using the set network-address hex # command, enter a network address from 30900000 to 3097FFFF. The network address for Banyan servers is the 32-bit hexadecimal serial number of the service node. This number is automatically read from the node server key.

  2. Globally enable the VINES protocol using the enable VINES command.

  3. Enable the interface cards that are to transmit and receive the VINES packets using the enable interface interface# command.

For configuration changes to take effect you must restart the router. Enter reload after the OPCON prompt (*) and answer yes to the following prompt: 

Are you sure you want to reload the router? (Yes or No):  yes

To view the configuration, enter the list command after the VINES config> prompt.

Running Banyan VINES on the Bridging Router

Banyan VINES servers must have this Banyan option to communicate with other servers or routers:

Server-to-server LAN.

To communicate across X.25 WANs, VINES servers directly connected to the WAN need these two options:

Server-to-server WAN
X.25 support on the server (hardware and software).

Running Banyan VINES over WAN Links

When you set up a PPP, Frame Relay, or X.25 link for use with VINES, you must set the HDLC speed of the link, even if you set the clocking to external.

If you set the HDLC speed to zero, VINES assumes that the speed is 56 Kbps. Do not set the speed to a value that is faster than the line.

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