Technical data

in which case the speciﬁed CTF command is executed as soon as TRACE is

running. When this command has been executed, you are returned to VMS; the

single exception to this rule is the ANALYZE command, which leaves you in the

TRACE utility when it has completed (that is, the CTF> prompt will appear). For

example:

$ TRACE START "ROUTING CIRCUIT LAN-0"

runs TRACE and immediately starts detached tracing at the speciﬁed tracepoint.

To exit from the TRACE utility and return to DCL, enter the following command:

CTF> EXIT

If you are currently performing live tracing, exitting from TRACE has the effect

of stopping tracing; that is, collection and display of trace records is stopped. If,

however, you are currently performing detached tracing, exitting from TRACE

has no effect on collection; the collection of trace records into a trace ﬁle will

continue under the control of the trace server process. To stop detached tracing

you must explicitly turn off the collection of trace records (see Section 3.5.5).

3.4.1 Tracing Phase IV Products

The DECnet/OSI for VMS versions of Digital’s networking products support CTF.

The Phase IV versions, however, do not support CTF; instead, they support the

NETTRACE utility. If you are tracing the Phase IV version of a networking

product, such as a previous, Phase IV version of VAX P.S.I., rather than the

DECnet/OSI for VMS version, use the NETTRACE utility rather than CTF.

To start NETTRACE, use the TRACE command with an appropriate qualiﬁer.

The qualiﬁers that you can specify in a TRACE command are:

• TRACE/PSI

• TRACE/ROUTER

• TRACE/SNA

See the Problem Solving Guide for the appropriate product for information about

using NETTRACE.

3.5 Starting and Stopping Collection of Trace Records

This section describes how you start and stop the collection of trace records from

tracepoints.

The CTF commands that start and stop the collection of trace records from

tracepoints refer to these tracepoints by name. Section 3.5.1 describes how local

and remote tracepoints are named and how you refer to them in CTF commands.

There are three ways to collect trace records from tracepoints:

• Detached tracing, in which trace records are written to a trace ﬁle.

Section 3.5.2 describes how you start detached tracing.

• Live tracing, in which trace records are displayed on your terminal as they

are collected. Section 3.5.3 describes how you start live tracing.

• Snapshot tracing, in which trace records are collected in a buffer until you

issue a command that either writes the buffer to a trace ﬁle or displays the

contents of the buffer on your terminal. Section 3.5.4 describes how you start

snapshot tracing.

Section 3.5.5 describes how you stop trace collection.

3–4 Using CTF