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snmpd(8)							     snmpd(8)



NAME

  snmpd, snmpd.conf - Simple Network Management	Protocol (SNMP)	agent daemon

SYNOPSIS

  /usr/sbin/snmpd [-t] [-d] [-p	port]

OPTIONS

  -d  Specifies	debug mode.  If	you specify this option, snmpd prints error
      information to stdout, but does not run as a daemon.

  -p port
      Specifies	the port to which the snmpd daemon listens for SNMP requests.
      The default is port 161, the well-known SNMP port.

  -t  Specifies	trace mode. If you specify this	option,	snmpd prints trace
      information to stdout.  You must specify the -d option with the -t
      option.

DESCRIPTION

  The snmpd daemon is an extensible SNMP agent that starts automatically at
  boot time.  It listens on the	snmp service port specified in the
  /etc/services	file for SNMP requests and for local subagents wishing to
  register extended MIBs.  The snmpd daemon processes SNMP requests for	MIB
  objects by communicating with	registered subagents.  The snmpd daemon
  receives and organizes the subagent replies and sends	the SNMP response to
  logically remote network management stations.

  The snmpd daemon is a	bilingual master agent,	and is capable of handling
  both SNMPv1 and SNMPv2c requests.  For information about building subagents
  and extensible SNMP support, refer to	the Network Programmer's Guide.

  Tru64	UNIX standard MIB support is implemented in the	subagent process
  /usr/sbin/os_mibs.  This process is typically	started	and stopped automati-
  cally	in conjunction with the	snmpd daemon.

  The snmpd daemon reads its configuration file, /etc/snmpd.conf, at startup
  time.	 You can change	the configuration by editing the /etc/snmpd.conf
  file,	as described in	the Configuring	snmpd section in this reference	page.

				     Note

       The default configuration grants	only read access to the	world, and
       does not	generate any traps.

  The snmpd daemon logs	error messages through the syslog function to the
  /usr/var/adm/syslog.dated/date/daemon.log log	file.




  Configuring snmpd


  The /etc/snmpd.conf file defines the initial values for four MIB variables,
  as well as access control based on community names and trap information, as
  follows:

       sysName		      name
       sysLocation	      location
       sysContact	      contact
       snmpEnableAuthenTraps  n
       community	      community-name  IP-address  privileges
       trap [v1|v2c]	      trap-community-name  IP-address[:port]

  If no	trap version is	specified, v1 is the default.  White space (tabs,
  spaces, line feeds, and carriage returns) and	blank lines are	ignored.

  The /etc/snmpd.conf file is defined as a Context-Dependent Symbolic Link
  (CDSL), and must be maintained as such.  See the System Administration
  manual for more information.

  MIB Variable Initialization


  When an entry	in the /etc/snmpd.conf file is one of the following MIB	vari-
  ables, it is assigned	the value that follows it:

       sysName		      name
       sysLocation	      location
       sysContact	      contact
       snmpEnableAuthenTraps  n

  According to MIB-II, the variables sysName, sysLocation, and sysContact can
  be any display string	of 0 to	255 NVT	ASCII characters. The value of the
  snmpEnableAuthenTraps	entry can be either 1 (enable traps) or	2 (disable
  traps); for example:

       sysName		       Presto
       sysLocation	       City, USA
       sysContact	       Kathy Berberian 555-7667
       snmpEnableAuthenTraps   1

  If the values	of the sysName,	sysLocation, and sysContact variables are
  modified by SNMP set commands, the new values	are updated in the snmpd.conf
  file.	 (The sysName variable does not	affect the system's host name.)	 If
  sysName is not present or commented out in the snmpd.conf file, the
  system's host	name is	used.

  Community Entries


  Community entries have the following format:

  community-name  IP-address  privileges

  community-name
      Can be any string.

  IP-address
      Indicates	the remote site	for which this community is valid. If the IP
      address is 0.0.0.0, any address can communicate using that community
      name.

  privileges
      Can be read for read-only	or write for read and write.

  The following	is a sample entry for the community variable:

       community test1	 130.117.1.20 read


  This example defines a community named test1 that allows read-only access
  from the IP address 130.117.1.20.

				     Note

       On Tru64	UNIX, the MIB-II implementation	supports write access to all
       MIB-II variables	so defined.  Authorized	parties	are able to change
       the Tru64 UNIX environment; such	as bring down an interface or delete
       an entry	from the routing table.

  Disabling snmpd


  By default, the snmpd.conf file contains a community entry that permits
  read access of all MIB variables via the community public.  You can con-
  strain access	to different communities by removing this default entry	and
  by adding entries with different community names.

  If you want to disable access	to MIB variables completely (some sites	might
  want to do this), the	recommended method is to remove	all community entries
  in the snmpd.conf file and to	issue the /sbin/init.d/snmpd read command to
  force	snmpd to reload	its configuration.

  Trap Community Entries


  Trap entries have the	following format:

  trap [version] trap-community-name  IP-address [:port]

  version
      Specifies	the SNMP version, either v1 or v2c.  If	not specified, v1 is
      the default.

  trap-community
      Can be any string.

  IP-address
      Indicates	the destination	address, in dot	notation, to which to send
      the trap PDU.

  :port
      Specifies	the port at the	destination address to which to	send the trap
      PDU. If no port is specified, port 162 is	the default.

  The following	sample trap entry indicates to the agent that if a trap	needs
  to be	sent, the trap PDU should be built using the community name test2 and
  sent to the trap port	at 128.169.4.15:

       trap test2   128.169.4.15

  The following	sample trap entry indicates to the agent that if a trap	needs
  to be	sent, the SNMPv1 trap PDU should be built using	the community name
  test1	and sent to the	trap port at 128.169.4.15:

       trap v1 test1   128.169.4.15

  The following	sample trap entry indicates to the agent that if a trap	needs
  to be	sent, the SNMPv2 trap PDU should be built using	the community name
  test2	and sent to the	port 5008 at 128.169.4.15:

       trap v2 test2   128.169.4.15:5008





  Rereading the	Daemon Configuration File (snmpd.conf)


  Sending the SIGHUP signal to snmpd causes it to reread the /etc/snmpd.conf
  file and and reload that information.	 To do this, issue the
  /sbin/init.d/snmpd read command.

  Dumping the Registry of MIBs and Subagents


  Sending the SIGUSR1 signal to	snmpd causes it	to dump	its subagent regis-
  tration database to the /var/tmp/snmpd_dump.log file.	To do this, issue the
  /sbin/init.d/snmpd dump command.

  Agent	Extensibility (AgentX)


  The snmpd daemon supports RFC	2741 for communication with MIB	implementa-
  tions	(called	subagents), for	example	os_mibs	and cpq_mibs.  This permits
  third-party subagents	that support AgentX to interoperate at the protocol
  level	with Tru64 UNIX	snmpd.	These subagents	do not require their own
  private SNMP agent.

  Since	the operating system's libesnmp.so library also	uses AgentX, all
  native subagents will	interoperate with third-party SNMP agents that sup-
  port AgentX.

  Cluster Alias	Support


  SNMP is a multi-instance service.  Therefore,	snmpd runs on each member of
  a cluster.  The snmpd	daemon will accept SNMP	messages received on cluster
  alias	addresses, but will process them differently than those	received on
  non-alias addresses.

  Since	SNMP/UDP messages sent to the same cluster alias address are
  delivered in round-robin fashion to different	cluster	members, snmpd
  processes them in the	context	of a restricted	"MIB view".  This MIB view is
  the set of MIB variables that	are identical in name and value	on each	clus-
  ter member.  Only these variables are	exported via cluster alias addresses.

  The snmpd daemon is made aware of subagent MIB variables by the AgentX
  registration mechanism.  Registrations made in the default mode are not
  part of the cluster alias MIB	view; they are available only when processing
  SNMP requests	received on non-alias addresses.  Registrations	using the
  AgentX context "cluster-alias" are made part of the cluster alias view;
  they available when processing messages received on cluster alias
  addresses.  (Native Tru64 UNIX subagents can accomplish this by using	the
  esnmp_register2 function. See	the Network Programmer's Guide for more
  information.

  The snmpd daemon does	not communicate	with subagents on different cluster
  members.  A subagent that registers MIB variables in the cluster alias view
  is responsible for ensuring that those variables are identical in name and
  value	on each	cluster	member.





FILES

  /etc/snmpd.conf
      The snmpd	daemon configuration file.

  /etc/services
      The file containing the port number on which snmpd listens.

  /usr/var/adm/syslog.dated/date/daemon.log
      The system daemon	log file, where	date is	the date.

  /usr/examples/esnmp/*
      This directory contains sample MIBs and scripts.

  /var/tmp/snmpd_dump.log
      The file containing a dump of the	snmpd daemon's MIB registry.

  /var/agentx
      This directory contains snmpd daemon's UNIX domain socket	directory.
      This socket listens for connection requests from subagent	processes.

SEE ALSO

  Commands: syslog(3), os_mibs(8), snmp_request(8), snmp_traprcv(8)

  Network Administration: Services

  Network Programmer's Guide

  For SNMP Version 1:

  RFC 1155, Structure and Identification of Management Information for
  TCP/IP-Based Internets

  RFC 1157, A Simple Network Management	Protocol

  RFC 1212, Concise MIB	Definitions

  RFC 1215, Conventions	for Defining Traps for Use With	the SNMP

  For SNMP Version 2:

  RFC 1901, Introduction to Community-based SNMPv2

  RFC 1902, Structure of Management Information	for Version 2 of the Simple
  Network Management Protocol (SNMPv2)

  RFC 1903, Textual Conventions	for Version 2 of the Simple Network Manage-
  ment Protocol	(SNMPv2)

  RFC 1904, Conformance	Statements for Version 2 of the	Simple Network
  Management Protocol (SNMPv2)

  RFC 1905, Protocol Operations	for Version 2 of the Simple Network Manage-
  ment Protocol	(SNMPv2)

  RFC 1906, Transport Mappings for Version 2 of	the Simple Network Management
  Protocol (SNMPv2)

  RFC 1907, Management Information Base	for Version 2 of the Simple Network
  Management Protocol (SNMPv2)

  RFC 1908, Coexistence	between	Version	1 and Version 2	of the Internet-
  standard Network Management Framework

  RFC 2089, V2ToV1 Mapping SNMPv2 onto SNMPv1 within a bi-lingual SNMP Agent

  RFC 2741, Agent Extensibility	(AgentX) Protocol Version 1

  RFC 2742, Definitions	of Managed Objects for Extensible SNMP Agents