Limax SNA Services

Routing Analysis Program

This program analyses route definitions, not the actual physical routes. The physical routes can be easily tested with a simple program in your network management system.

Analysing route definitions will show how logical and complete your definitions are. It is particularly useful for planning routing changes so that they may be implemented with the minimum disruption. The program may be run on either your current definitions or a proposed new set of definitions.

Our routing analysis program reads all the path tables within the network and produces the following reports for each origin subarea:

Explicit route report

This report lists all explicit routes (ERs) to each destination subarea. An ER is a series of one or more transmission groups connecting two subarea nodes.

Here is a sample ER report for subarea 2 in a small network of three hosts and four NCPs.

                               ERs from subarea 2
                              ===================

DestSA      ER0     ER1     ER2     ER3     ER4     ER5     ER6     ER7

1           5,1     7,1
3           7,1     7,1     5,1
5           5,1
6           5,1     7,1     7,1     7,1
7           7,1
8           7,1     7,1     5,1

Virtual route report

This report lists all virtual routes (VRs) to each destination subarea. A VR is a bi-directional logical connection between two subarea nodes.

Here is a sample VR report for subarea 2 in a small network of three hosts and four NCPs.

                               VRs from subarea 2
                              ===================

DestSA      VR0     VR1     VR2     VR3     VR4     VR5     VR6     VR7

1            0                               0       1
3            0                               0       1       2
5            0       0               0       0
6            0       0               0       0       1       2       3
7            0       0               0       0
8            0       1               0       0       1       2       0

Route analysis report

This report lists all routes to each destination subarea, detecting and highlighting any problem routes:

• incomplete routes - routes not defined in all relevant subareas
• looping routes - routes that loop round a series of subareas without ever reaching their intended destination
• non-reversible routes - routes that are complete in one direction only

Here is a sample route analysis report for subarea 2 in a small network of three hosts and four NCPs.

                             Routes from subarea 2
                             =====================

DestSA   ER     AdjSA,TG ...

1        ER0    5,1    1,1
1        ER1    7,1    1,1

3        ER0    7,1    8,1    3,1
3        ER1    7,1    8,2    3,1
3        ER2    5,1    8,3    3,1    *** not reversible ***

5        ER0    5,1

6        ER0    5,1    6,4
6        ER1    7,1    6,4
6        ER2    7,1    8,1    6,5
6        ER3    7,1    8,2    6,5

7        ER0    7,1

8        ER0    7,1    8,1
8        ER1    7,1    8,2
8        ER2    5,1    8,3    *** not reversible ***