Logging Trace Information

The SunOS 5.x streams strace (1M) command lets you log trace information. See the strace man page for details on the command's use.

The strace command must be followed by three arguments:

module id

Table 11-2 lists the possible values:

link number

The number of the link over which the driver you are tracing is running, or all to specify all links.

level

The tracing level that allows you to receive more or fewer packets or frames. Table 11-3 lists the available strace tracing levels for the X.25, LAPB, and LLC2 drivers.

Specify all to trace all available levels. For example, to trace X.25 PLP packets on all links at all tracing levels, type:

# /usr/sbin/strace 200 all all

Note that strace is owned by root and is executable only by root.

The tracing of an incoming event does not mean that the packet or frame has been accepted by the driver at the layer you are tracing. This is because, for a given layer, the tracing of incoming events is triggered on receiving data from the layer below. At this point, the packet or frame is not yet verified. If the packet or frame is subsequently found to be in error, it might be discarded or cause some further protocol action.

The successful completion of a trace of an outgoing event at the X.25 layer does not necessarily mean that the packet has been sent to the link layer. Following tracing, various consistency checks are performed on the link-level database. If these checks fail, the packet will be discarded. At the LAPB and LLC2 layers, successful tracing does mean that the frame was sent to the WAN or LAN driver. However, it does not mean that the frame will be transmitted on the line.