SNMPD(1) Net-SNMP SNMPD(1)
snmpd - daemon to respond to SNMP request packets.
snmpd [OPTIONS] [LISTENING ADDRESSES]
snmpd is an SNMP agent which binds to a port and awaits requests from SNMP management
software. Upon receiving a request, it processes the request(s), collects the requested
information and/or performs the requested operation(s) and returns the information to the
-a Log the source addresses of incoming requests.
-A Append to the log file rather than truncating it.
-c FILE Read FILE as a configuration file.
-C Do not read any configuration files except the one optionally specified by the -c
-d Dump (in hexadecimal) the sent and received SNMP packets.
Turn on debugging output for the given TOKEN(s). Without any tokens specified, it
defaults to printing all the tokens (which is equivalent to the keyword "ALL").
You might want to try ALL for extremely verbose output. Note: You can not put a
space between the -D flag and the listed TOKENs.
-f Do not fork() from the calling shell.
-g GID Change to the numerical group ID GID after opening listening sockets.
Display a brief usage message and then exit.
-H Display a list of configuration file directives understood by the agent and then
This option specifies which modules you do (or do not) want to be initialized when
the agent starts up. If the comma-separated INITLIST is preceded with a '-', it
is the list of modules that you do not want to be started. Otherwise, INITLIST is
the list of modules to be started.
To get a list of compiled modules, run the agent with the arguments -Dmib_init -H
(assumes you have debugging support compiled in).
Log all output from the agent (including stdout and stderr) to FILE. If no file-
name is given, log to a default file set at compile time (normally
-L Do not open a log file; print all messages to stderr instead.
-P FILE Save the process ID of the daemon in FILE.
-q Print simpler output for easier automated parsing.
-r Do not require root access to run the daemon. Specifically, do not exit if files
only accessible to root (such as /dev/kmem etc.) cannot be opened.
-s Use syslog for logging.
-u UID Change to the user ID UID (which can be given in numerical or textual form) after
opening listening sockets.
Print version information for the agent and then exit.
-V Symbolically dump SNMP transactions.
Listens for AgentX connections on the specified address rather than the default
'/var/agentx/master'. The address can either be a Unix domain socket path, or the
address of a network interface. The format is the same as the format of listening
addresses described below.
-X Run as an AgentX subagent rather than as an SNMP master agent.
By default, snmpd listens for incoming SNMP requests only on UDP port 161. However, it is
possible to modify this behaviour by specifying one or more listening addresses as argu-
ments to snmpd. A listening address takes the form:
At its simplest, a listening address may consist only of a port number, in which case
snmpd listens on that UDP port on all IPv4 interfaces. Otherwise, the <transport-address>
part of the specification is parsed according to the following table:
<transport-specifier> <transport-address> format
udp hostname[:port] or IPv4-address[:port]
tcp hostname[:port] or IPv4-address[:port]
aal5pvc or pvc [interface.][VPI.]VCI
udp6 or udpv6 or udpipv6 hostname[:port] or IPv6-address[:port]
tcp6 or tcpv6 or tcpipv6 hostname[:port] or IPv6-address[:port]
Note that <transport-specifier> strings are case-insensitive so that, for example, "tcp"
and "TCP" are equivalent. Here are some examples, along with their interpretation:
127.0.0.1:161 listen on UDP port 161, but only on the loopback interface. This
prevents snmpd being queried remotely (which is a bit pointless).
The ":161" is redundant here since that is the default SNMP port
in any case.
TCP:1161 listen on TCP port 1161 on all IPv4 interfaces.
ipx:/40000 listen on IPX port 40000 on all IPX interfaces.
unix:/tmp/local-agent listen on the Unix domain socket /tmp/local-agent.
/tmp/local-agent identical to the previous specification, since the Unix domain is
the default transport iff the first character of the <transport-
address> is a '/'.
PVC:161 listen on the AAL5 permanent virtual circuit with VPI=0 and
VCI=161 (decimal) on the first ATM adapter in the machine.
udp6:10161 listen on port 10161 on all IPv6 interfaces.
Note that not all the transport domains listed above will always be available; for
instance, hosts with no IPv6 support will not be able to use udp6 transport addresses, and
attempts to do so will result in the error "Error opening specified endpoint". Likewise,
since AAL5 PVC support is only currently available on Linux, it will fail with the same
error on other platforms.
snmpd checks for the existence of and parses the following files:
Common configuration for the agent and applications. See snmp.conf(5) for details.
Agent-specific configuration. See snmpd.conf(5) for details. These files are
optional and may be used to configure access control, trap generation, subagent pro-
tocols and much else besides.
In addition to these two configuration files in /usr/share/snmp, the agent will read
any files with the names snmpd.conf and snmpd.local.conf in a colon separated path
specified in the SNMPCONFPATH environment variable.
The agent will also load all files in this directory as MIBs. It will not, however,
load any file that begins with a '.' or descend into subdirectories.
(in recommended reading order)
4th Berkeley Distribution 7 Feb 2002 SNMPD(1)