Networking Concepts

Address Resolution

 

The centralized theory requires each node on the internet to have the

 

same network directory. This means that every node in the network

 

must have an entry in the network directory. The advantage to this is

 

that you update the network directory in one place, then copy it to the

 

rest of the world. The disadvantage is that network directories for large

 

internets are going to be large.

 

The recommended way to create and maintain your network directory

 

using the centralized method is to assign a single node as the central

 

administrative node. You configure the network directory on this node

 

and then copy it to all other nodes on the network. When the network

 

directory is updated, it is updated on the central administrative node,

 

then copied to the other nodes. This procedure decreases the possibility

 

of incompatible directories. You may want to assign a central

 

administrative node for each network or for the entire internet.

 

The decentralized theory suggests that each network directory be

 

configured individually on each node. The advantage to this is that you

 

can customize the network directory on each node for security purposes

 

using local and global entries. The network directory will also be

 

smaller because it will only contain entries for that particular node.

 

However, updates must be done manually on each node.

 

Copying and Merging Network Directory Files

 

The first time you configure the network directory, an entry for all

 

remote IP addresses must be added manually using the NMMGR

 

screens. After the first network directory is configured, you can use the

 

MPE STORE and RESTORE commands to copy the network directory to

 

other nodes. (This is assuming you have adopted the centralized

 

method of network directory maintenance. If you use the decentralized

 

method, you must always use NMMGR to create and maintain the

 

network directory.)

 

The network directory uses a KSAM file pair. Therefore, when copying a

NOTE

 

directory, be sure to copy both the data file and the key file. The system

 

names the key file automatically using the first six letters of the

 

network directory file name appended with a K. For example,

 

NSDIRK.NET.SYS is the name of the key file associated with the data file

 

NSDIR.NET.SYS.

 

Once a network directory has been established on each node in the

 

internet, you can set up a job stream to automate network directory

 

updates. The MERGEDIR command is part of a maintenance interface

 

provided primarily to support the updating of directories using a batch

 

job. Using this method, a job or series of jobs can be scheduled at

 

regular intervals to copy and then merge remote directories into the

 

local-system directory. See the MERGEDIR and the MAKESTREAM

 

commands in Using the Node Management Services (NMS) Utilities.

Chapter 2

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