Route Permission Table (SAP Library - SAProuter (BC-CST-NI))

Route Permission Table

Definition

The route permission table contains the host names and port numbers of the predecessor and successor points on the route (from the SAProuter’s point of view), as well as the passwords required to set up the connection (corresponds to a substring, cf. Route Strings). It is used to specify which connections are allowed and which prohibited by SAProuter. It also specifies whether SNC connections are set up and which these are.

Structure

Standard Entries

Standard entries in a route permission table appear as follows:

P/S/D <source-host> <dest-host> <dest-serv> <password>

<source-host> and <dest-host> could be SAProuters.

The beginning of the line can be as follows:

P(ermit) causes SAProuter to set up the connection. P(ermit) entries can contain a password. SAProuter checks whether this password corresponds to that sent by the client.

Directly after the P, you can also specify the maximum number of SAProuters permitted before and after this SAProuter on the route for the connection to be allowed: Pv,n – here v denotes the maximum number of preceding SAProuters on the route, n the maximum number of following ones.

S(ecure) only allows connections with the SAP Protocol; connections with other protocols (such as TCP) are not allowed, see Network Security with SAProuter.

D(eny) prevents the connection from being set up.

You can also add comment lines, which must begin with ‘#’.

If a <source-host> client wants to set up a connection to <dest-host> <dest-serv> using SAProuter, SAProuter checks its route permission before the connection is set up. If the password and route SAProuter has received correspond to the entries in the route permission table, SAProuter sets up the connection. In this is not the case, SAProuter does not set up the connection, and issues the message Route permission denied.

Example Example of a Route Permission Table

SNC Entries

SNC entries always start with the letter K (for key).

There are two types of SNC entries:

KT entries (key target)

This defines which connections should be SNC connections. This can be defined for both incoming and outgoing connections (from the point of view of this SAProuter).

Incoming connections

The syntax is KT <SNCname src-host> <src-host> <src-serv>.

This means that connections coming from the host <src-host> <src-serv> with the SNC name <SNCname src-host> should be SNC connections.

The user can thus define that service connections from SAP must be SNC connections.

Outgoing connections

The syntax is KT <SNCname dest-host> <dest-host> <dest-serv>. This means that connections from the SAProuter to <dest-host> <dest-serv> with the SNC name <SNCname> should be SNC connections.

Caution

To make SNC connections possible, the appropriate SAProuters need to have been started with the option -K and the route permission table must contain the appropriate KT entry.

KD, KP, and KS entries

These have the following syntax:

K<D/P/S> <SNCname source-host> <dest-host> <dest-serv> <Kennwort>. This means that an (encrypted) SNC connection from <SNCname source-host> via SAProuter to <dest-host> <dest-serv> is set up when the route string contains the correct <password>.

Example Example of a Route Permission Table with SNC

Evaluation of the Route Permission Table

The following rules apply when the SAProuter evaluates the route permission table.

First Match

The first entry in the route permission table for which source address, target address, and target port match is decisive. In other words, in the Example of a Route Permission Table, this means that the connection from host1 to host2, service serviceX, is not allowed (because of the first entry) although all connections with service serviceX are allowed according to the third entry.

Wildcards Exception

If the SAProuter is the last SAProuter on the route (for example, the front end), and the service is not an SAP service (not an SAP protocol), a wildcard ("*") cannot be used with the service. The connection is only allowed if the non-SAP service is explicitly selected. If the example given above contained a * instead of telnet, and the SAProuter was the last one on the route, the telnet connection would not be set up.

See also:

Creating a Route Permission Table