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 |
| |
| commands in Using the Node Management Services (NMS) Utilities. |
Chapter 2 | 37 |