SCTP Administrator's Guide

The nettl Command
The nettl command is a tool used to capture network events or packets. It is also
used to control the network tracing and logging. Logging is a means of capturing
network activities, such as state changes, errors, and connection establishment. Tracing
is used to capture or obtain a snapshot of inbound and outbound packets that pass
through the network, including packet loopback or header information.
The sctpd Application
The sctpd application enables you to manage domain name resolution requests, to
support the SCTP hostname parameter. It automatically configures interfaces into
SCTP, whenever an interface is configured.
When IP addresses are required for a peer's hostname, the SCTP module sends the
request to sctpd. The sctpd application looks up the hostname and sends the IP
addresses, or an error if the hostname cannot be resolved to the SCTP module.
The sctpd application supports automatic configuration of the interfaces. When an
interface is configured, the sctpd application automatically configures the same into
SCTP, using a poll. The sctpd application checks and configures all the interfaces at
the given interval of time. This interval is configured using the
/etc/rc.conf/sctprcconf file. For more information about using the
/etc/rc.conf/sctprcconf file, see “Using the /etc/rc.conf/sctprcconf
File” (page 38)
The sctpd application is available at the following location:
/usr/sbin/sctpd
SCTP Support for sctpd
The sctpd application supports the following command-line options specific to SCTP:
-t <sec> This option enables you to configure the poll timer interval for sctpd.
During each of these intervals, sctpd scans the and configures all the
interfaces. The timer is used to initiate a SIGALRM, and when this signal
is received, sctpd verifies all the interfaces present and configures them.
-d
This option provides an event driven logging facility. It is event driven,
because logging is mostly error-based (failure of malloc() or failure of
fork() is treated as an event and is suitably logged). The “DEBUG”
feature is built into the sctpd binary. This option also provides
debugging information related to Domain Name System (DNS) and the
interface configurations that sctpd handles.
The -t and -d options can be configured using the /etc/rc.conf/sctprcconf
file. For more information about using the /etc/rc.conf/sctprcconf file, see
“Using the /etc/rc.conf/sctprcconf File” (page 38)
24 Introduction