SNMPD.CONF(5) BSD File Formats Manual SNMPD.CONF(5)
snmpd.conf -- Simple Network Management Protocol daemon configuration
snmpd.conf is the configuration file for the snmpd(8) daemon.
The snmpd.conf file is divided into three main sections:
User-defined variables may be defined and used later, simplifying
the configuration file.
Global runtime settings for snmpd(8).
USM user definitions.
Custom configuration of SNMP object identifiers and values.
The current line can be extended over multiple lines using a backslash
('\'). Comments can be put anywhere in the file using a hash mark ('#'),
and extend to the end of the current line. Care should be taken when
commenting out multi-line text: the comment is effective until the end of
the entire block.
Argument names not beginning with a letter, digit, or underscore must be
Additional configuration files can be included with the include keyword,
Macros can be defined that will later be expanded in context. Macro
names must start with a letter, digit, or underscore, and may contain any
of those characters. Macro names may not be reserved words (for example,
community, system, or oid). Macros are not expanded inside quotes.
listen on $ext_addr
The following options can be set globally:
filter-routes (yes | no)
If set to yes, ask the kernel to filter route update messages on
the routing socket. Routing table information will not be avail-
able, but CPU use will be reduced during bulk updates. The
default is no.
listen on address
Specify the local address snmpd(8) should listen on for incoming
read-only community string
Specify the name of the read-only community. The default value
read-write (community string | disabled)
Specify the name of the read-write community, or disallow writes
completely. The default value is private.
seclevel (none | auth | enc)
Specify the lowest security level that snmpd(8) accepts:
none Both authentication and encryption of messages is
optional. This is the default value.
auth Authentication of messages is mandatory. snmpd(8)
will discard any messages that don't have a valid
digest. Encryption of messages is optional.
enc Messages must be encrypted and must have a valid
digest for authentication. Otherwise they will be
If the chosen value is different from none snmpd(8) will accept
only SNMPv3 requests since older versions neither support authen-
tication nor encryption.
socket "path" [restricted | agentx]
Create a control socket at path. If restricted is specified, a
restricted control socket will be created. If agentx is speci-
fied, a socket which speaks the AgentX protocol will be created.
Multiple restricted and agentx sockets may be created. By
default /var/run/snmpd.sock is created and no other sockets are
system contact string
Specify the name or description of the system contact, typically
a name or an e-mail address. The default value is root@hostname
using the hostname of the local machine.
system description string
Specify a description of the local system. The default value is
the operating system identification as printed by the uname(1)
command using the -a flag:
OpenBSD myhost.example.com 4.2 GENERIC#595 i386
system location string
Specify the string describing the location of the local system,
typically a physical location. The default value is an empty
system name string
Specify the name of the local system, typically a fully-qualified
domain name. The default value is the hostname of the local sys-
system oid oid-string
Specify the authoritative identification of the local system.
The default value is 126.96.36.199.4.1.30155.23.1
ing a common OpenBSD system.
system services number
Specify a magic value which indicates the set of services that
the local system may provide. Refer to the sysServices descrip-
tion in the SNMP MIB for details.
trap community string
Specify the name of the trap community. The default value is
trap handle oid "command"
Execute command upon receipt of an SNMP trap that begins with a
prefix of oid. Alternately, the string "default" may be used, in
which case the prefix used is 1.3. The invoked command will
receive the following information about the trap on standard
input, one per line, in this order: the resolved hostname of the
host sending the trap, the IP address of the host sending the
trap, and any variable bindings contained in the trap (the OID
followed by the value, separated by a single space).
trap receiver string [oid oid-string] [community string]
Specify the address or FQDN of a remote trap receiver for outgo-
ing traps sent by snmpd(8). This option may be specified multi-
ple times. The daemon will send outgoing traps using the revised
SNMPv2 format and the configured trap community. The default
community is specified by the global trap community option.
Users for the SNMP User-based Security Model (USM, RFC 3414) must be
defined in the configuration file:
user name [authkey key auth hmac] [enckey key enc cipher]
Defines a known user. The authkey keyword is required to specify
the digest key used to authenticate messages. If this keyword is
omitted then authentication is disabled for this user account.
Optionally the HMAC algorithm used for authentication can be speci-
fied. hmac must be either hmac-md5 or hmac-sha1. If omitted the
default is hmac-sha1.
With enckey the encryption key used to encrypt and decrypt messages
for privacy is defined. Without an enckey specification the user
account will neither accept encrypted incoming messages nor will it
encrypt outgoing messages. The enc algorithm can be either des or
aes and defaults to des.
Any user account that has encryption enabled requires authentica-
tion to be enabled too.
It is possible to specify user-defined OIDs in the configuration file:
oid oid-string name name [read-only | read-write] [type] value
Return the specified value to the client for this OID. The
read-write option may allow the client to override it, and the
type is either string or integer.
/etc/snmpd.conf Default location of the configuration file.
The following example will tell snmpd(8) to listen on localhost, override
the default system OID, set the magic services value and provides some
custom OID values:
listen on 127.0.0.1
system oid 188.8.131.52.4.1.30155.23.2
system services 74
oid 184.108.40.206.4.1.30155.42.1 name myName read-only string "humppa"
oid 220.127.116.11.4.1.30155.42.2 name myStatus read-only integer 1
The next example will enforce SNMPv3 with authenticated and encrypted
communication and the user-based security model. The configuration
defines two users, the first one is using the aes encryption algorithm
and the second one the default des algorithm.
user "xaver" authkey "password123" enc aes enckey "321drowssap"
user "traudl" authkey "password456" enckey "654drowssap"
The snmpd.conf file format first appeared in OpenBSD 4.3.
The snmpd(8) program was written by Reyk Floeter <email@example.com>.
BSD May 30, 2017 BSD