DTRACE_MIB(4)

NAME
dtrace_mib - a DTrace provider for Management Information Base

SYNOPSIS
mib:module:count:counter

In config(5):
options KDTRACE_MIB_SDT

DESCRIPTION
The mib provider allows tracing of Management Information Base stats counters.

The list of instrumented modules includes:
ah  IP Authentication Header (RFC 2402), ipsec(4)
esp IP Encapsulating Security Payload (RFC 1827, RFC 2406), ipsec(4)
icmp
    icmp(4)
icmp6
    icmp6(4)
ip  ip(4)
ip6 ip6(4)
ipcomp
    IP Payload Compression Protocol, ipsec(4)
ipsec
    ipsec(4)
tcp tcp(4)
udp udp(4)

The mib:module:count:counter probes fire when the counter in modules increases.

The first probe argument, uint64_t args[0], is the increment that the counter will increase by.

Note that some probes like mib:esp:count:esps_hist or mib:icmp6:count:icp6s_outhist provide additional probe-specific arguments.

EXAMPLES

  Example 1 : Tracing IP Stats Counters
When debugging network issues one common clue is an unexpectedly incrementing error counter. This is helpful, in that it gives us an idea of what might be going wrong, but often these counters may be incremented in different functions.

Trace all mib probes in the ip(4) module and print the current count and a stack trace:

    # dtrace -n 'mib:ip:count: { printf("%d", arg0); stack(); }'
    dtrace: description 'mib:ip:count: ' matched 29 probes
    CPU     ID                    FUNCTION:NAME
      7  98784               count:ips_localout 1
                  kernel`ip_output+0x17a2
                  kernel`udp_send+0xaca
                  kernel`sosend_dgram+0x315
                  kernel`sousrsend+0x79
                  kernel`kern_sendit+0x1be
                  kernel`sendit+0x1ab
                  kernel`sys_sendmsg+0x5b
                  kernel`amd64_syscall+0x169
                  kernel`0xffffffff81094b8b

SEE ALSO
dtrace(1), dtrace_ip(4), dtrace_tcp(4), dtrace_udp(4), tracing(7), sysctl(8)

STANDARDS
The probe descriptions in the FreeBSD mib provider are not compatible with those in the Solaris/illumos mib provider.

AUTHORS
-nosplit The mib provider was added to FreeBSD by Kristof Provost <kp@FreeBSD.org>.

This manual page was written by Mateusz Piotrowski <0mp@FreeBSD.org>.