NAME
snmpcmd - options and behaviour common to
most of the Net-SNMP command-line tools
# 注释 ：snmpcmd 并不是一个命令，而是指
snmp 的相关命令
# 该 manual 主要讲述了 snmp
命令的一些通用的选项的用法
SYNOPSIS
snmpcmd [OPTIONS] AGENT
[PARAMETERS]
# 注释 ：snmp 相关命令的语法格式都是
：snmpcmd [option] agent [parameters]
DESCRIPTION
This manual page describes the common options for the
SNMP commands: snmpbulkget, snmpbulkwalk, snmpdelta,
snmpget, snmpgetnext, snmpnetstat, snmpset,
snmpstatus, snmptable, snmptest, snmptrap,
snmpdf, snmpusm , snmpwalk . The command line applications use the
SNMP protocol to communicate with an SNMP capable network entity, an agent.
Individual applications typically (but not necessarily) take additional
parameters that are given after the agent specification. These parameters are
documented in the manual pages for each application.
OPTIONS
- -3[MmKk]
0xHEXKEY
- Sets the keys to be used for SNMPv3
transactions. These options allow you to set the master authentication and
encryption keys (-3m and -3M respectively) or set the localized authentication
and encryption keys (-3k and -3K respectively). SNMPv3 keys can be either passed
in by hand using these flags, or by the use of keys generated from passwords
using the -A and -X flags discussed below. For further details on SNMPv3 and its
usage of keying information, see the Net-SNMP tutorial web site ( ). Overrides the defAuthMasterKey (-3m),
defPrivMasterKey (-3M), defAuthLocalizedKey (-3k) or defPrivLocalizedKey (-3K)
tokens, respectively, in the snmp.conf file, see (5).
# 注释 ：
- -a
authProtocol
-
- Set the authentication protocol (MD5 or SHA)
used for authenticated SNMPv3 messages. Overrides the defAuthType token
in the snmp.conf file.
# 注释 ：
-
- -A
authPassword
-
- Set the authentication pass phrase used for
authenticated SNMPv3 messages. Overrides the defAuthPassphrase token in
the snmp.conf file. It is insecure to specify pass phrases on the command
line, see (5).
# 注释 ：
-
- -c
community
-
- Set the community string for SNMPv1/v2c
transactions. Overrides the defCommunity token in the snmp.conf
file.
# 注释 ：-c 选项用于指定 community
string 。如果没有 -c 选项，默认使用 snmp.conf 中的 defCommunity 选项的值
- -d
- Dump (in hexadecimal) the raw SNMP packets
sent and received.
# 注释 ：-d 选项用于导出16进制格式的 snmp
数据包
- -D
TOKEN[,...]
-
- Turn on debugging output for the given
TOKEN(s). Try ALL for extremely verbose output.
# 注释
- -e
engineID
-
- Set the authoritative (security) engineID
used for SNMPv3 REQUEST messages. It is typically not necessary to specify this,
as it will usually be discovered automatically.
-
- -E
engineID
-
- Set the context engineID used for SNMPv3
REQUEST messages scopedPdu. If not specified, this will default to the
authoritative engineID.
-
- -h, --help
-
- Display a brief usage message and then exit.
# 注释 ：-h
选项打印帮助信息然后退出
- -H
- Display a list of configuration file
directives understood by the command and then exit.
# 注释 ：-H
选项打印该命令所知道的配置文件的指令并退出。
- -I
[brRhu]
-
- Specifies input parsing options. See
INPUT OPTIONS below.
# 注释 ：-I
选项用于指定输入选项
-
- -l secLevel
-
- Set the securityLevel used for SNMPv3
messages (noAuthNoPriv|authNoPriv|authPriv). Appropriate pass phrase(s) must
provided when using any level higher than noAuthNoPriv. Overrides the
defSecurityLevel token in the snmp.conf file.
-
- -L
[eEfFoOsS]
-
- Specifies output logging options. See
LOGGING OPTIONS below.
# 注释 ：-L
选项用于指定日志方面的选项
- -m
MIBLIST
-
- Specifies a colon separated list of MIB
modules (not files) to load for this application. This overrides (or augments)
the environment variable MIBS, the snmp.conf directive mibs, and
the list of MIBs hardcoded into the Net-SNMP library.
- If MIBLIST has a leading
'-' or '+' character, then the MIB modules listed are loaded in addition to the
default list, coming before or after this list respectively. Otherwise, the
specified MIBs are loaded instead of this default list.
- The special
keyword ALL is used to load all MIB modules in the MIB directory search
list. Every file whose name does not
begin with "." will be parsed as if it were a MIB file.
# 注释 ：-m 用于指定要加载的 MIB 模块，用 :
分隔。该选项覆盖 MIBS 变量和 snmp.conf 中的 mibs 指令
# 如果 前面有 +
号则表示“额外”要加载的 moudle ，如果是 - 号则表示不加载指定的 moudle
# 如果没有 + 或者 -
号，则表示只加载指定的模块
-
- -M
DIRLIST
-
- Specifies a colon separated list of
directories to search for MIBs. This overrides (or augments) the environment
variable MIBDIRS, the snmp.conf directive mibdirs, and the default
directory hardcoded into the Net-SNMP library (/usr/share/snmp/mibs).
-
- If DIRLIST has a leading '-' or '+'
character, then the given directories are added to the default list, being
searched before or after the directories on this list respectively. Otherwise,
the specified directories are searched instead of this default list.
# 注释 ：-M
指定一个用 : 分隔的目录列表，表示查找 MIB 的路径
-
Note that the directories appearing later in
the list have have precedence over earlier ones. To avoid searching any MIB
directories, set the MIBDIRS environment variable to the empty string ("").
# 注释 ：有一点要注意，
中的目录是按从右到左的顺序搜索的，而不是从左到右。
# 如果要禁止 MIB 目录搜索，可以把 MIBDIRS
变量设置为 ""
-
Note that MIBs specified using the -m option
or the mibs configuration directive will be loaded from one of the
directories listed by the -M option (or equivalents). The mibfile
directive takes a full path to the specified MIB file, so this does not need to
be in the MIB directory search list.
- -n
contextName
-
- Set the contextName used for SNMPv3
messages. The default contextName is the empty string "". Overrides the
defContext token in the snmp.conf file.
-
- -O
[abeEfnqQsStTuUvxX]
-
- Specifies output printing options. See
OUTPUT OPTIONS below.
-
# 注释 ：-O
选项设置输出选项
- -P
[cdeRuwW]
-
- Specifies MIB parsing options. See MIB
PARSING OPTIONS below.
# 注释 ：-P 选项设置 MIB
解释选项
- -r
retries
-
- Specifies the number of retries to be used
in the requests. The default is 5.
# 注释 ：-r
选项设置请求的重试次数。默认为5
-
- -t
timeout
- Specifies the timeout in seconds between
retries. The default is 1.
# 注释 ：-t
选项设认超时。默认为1秒
- -u
secName
-
- Set the securityName used for authenticated
SNMPv3 messages. Overrides the defSecurityName token in the
snmp.conf file.
-
- -v
1 | 2c | 3
-
- Specifies the protocol version to use: 1
(RFCs 1155-1157), 2c (RFCs 1901-1908), or 3 (RFCs 2571-2574). The default is
typically version 3. Overrides the defVersion token in the
snmp.conf file.
# 注释 ：-v 设置使用的协议版本。有 1，2c，3
这三个值。默认是3。该选项覆盖 snmp.conf 中的 defVersion 选项
- -V,
--version
- Display version information for the
application and then exit.
# 注释 ：-V
选项打印程序版本并退出
- -x
privProtocol
-
- Set the privacy protocol (DES or AES) used
for encrypted SNMPv3 messages. Overrides the defPrivType token in the
snmp.conf file. This option is only valid if the Net-SNMP software was
build to use OpenSSL.
-
- -X
privPassword
-
- Set the privacy pass phrase used for
encrypted SNMPv3 messages. Overrides the defPrivPassphrase token in the
snmp.conf file. It is insecure to specify pass phrases on the command
line, see (5).
-
- -Z
boots,time
-
- Set the engineBoots and engineTime used for
authenticated SNMPv3 messages. This will initialize the local notion of the
agents boots/time with an authenticated value stored in the LCD. It is typically
not necessary to specify this option, as these values will usually be discovered
automatically.
-
- --name=value
-
- Allows to specify any token ("name")
supported in the snmp.conf file and sets its value to "value". Overrides
the corresponding token in the snmp.conf file. See (5) for the full list of
tokens.
AGENT SPECIFICATION
The string AGENT in the
SYNOPSIS above specifies the remote SNMP entity with which to
communicate. This specification takes the form:
- [:]
At its simplest, the AGENT
specification may consist of a hostname, or an IPv4 address in the standard
"dotted quad" notation. In this case, communication will be attempted using
UDP/IPv4 to port 161 of the given host. Otherwise, the
part of the specification is parsed according to the following table:
-
-
-
format
- udp
- hostname[:port] or
IPv4-address[:port]
- tcp
- hostname[:port] or
IPv4-address[:port]
- unix
- pathname
- ipx
- [network]:node[/port]
- aal5pvc or pvc
- [interface.][VPI.]VCI
- udp6 or udpv6 or udpipv6
- hostname[:port] or IPv6-address:port
or '['IPv6-address']'[:port]
- tcp6 or tcpv6 or tcpipv6
- hostname[:port] or IPv6-address:port
or '['IPv6-address']'[:port]
Note that strings
are case-insensitive so that, for example, "tcp" and "TCP" are equivalent. Here
are some examples, along with their interpretation:
- hostname:161
- perform query using UDP/IPv4 datagrams to
hostname on port 161. The ":161" is redundant here since that is
the default SNMP port in any case.
- udp:hostname
- identical to the previous specification. The
"udp:" is redundant here since UDP/IPv4 is the default transport.
- TCP:hostname:1161
- connect to hostname on port
1161 using TCP/IPv4 and perform query over that connection.
- ipx::00D0B7AAE308
- perform query using IPX datagrams to node
number 00D0B7AAE308 on the default network, and using the default IPX
port of 36879 (900F hexadecimal), as suggested in RFC 1906.
- ipx:0AE43409:00D0B721C6C0/1161
- perform query using IPX datagrams to port
1161 on node number 00D0B721C6C0 on network number
0AE43409.
- unix:/tmp/local-agent
- connect to the Unix domain socket
/tmp/local-agent, and perform the query over that connection.
- /tmp/local-agent
- identical to the previous specification,
since the Unix domain is the default transport iff the first character of the
is a '/'.
- AAL5PVC:100
- perform the query using AAL5 PDUs sent on
the permanent virtual circuit with VPI=0 and VCI=100 (decimal) on the first ATM
adapter in the machine.
- PVC:1.10.32
- perform the query using AAL5 PDUs sent on
the permanent virtual circuit with VPI=10 (decimal) and VCI=32 (decimal) on the
second ATM adapter in the machine. Note that "PVC" is a synonym for "AAL5PVC".
- udp6:hostname:10161
- perform the query using UDP/IPv6 datagrams
to port 10161 on hostname (which will be looked up as an AAAA
record).
- UDP6:[fe80::2d0:b7ff:fe21:c6c0]
- perform the query using UDP/IPv6 datagrams
to port 161 at address fe80::2d0:b7ff:fe21:c6c0.
- tcpipv6:[::1]:1611
- connect to port 1611 on the local host
(::1 in IPv6 parlance) using TCP/IPv6 and perform query over that
connection.
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 "Unknown host". Likewise, since AAL5 PVC support is only
currently available on Linux, it will fail with the same error on other
platforms.
MIB PARSING
OPTIONS
The Net-SNMP MIB parser mostly adheres to
the Structure of Management Information (SMI). As that specification has changed
through time, and in recognition of the (ahem) diversity in compliance expressed
in MIB files, additional options provide more flexibility in reading MIB files.
-Pc
- Allow ASN.1 comments to extend to the end of
the MIB source line. Strictly speaking, a second appearance of "--" should
terminate the comment, but this breaks some MIB files. This behaviour can also
be set with the configuration token strictCommentTerm.
- -Pd
- Disables saving the DESCRIPTION of MIB
objects when parsing MIB files, reducing the amount of memory used by the
running application.
# 注释 ：-Pd 表示在解释 MIB
文件时，禁止保存描述信息，以节省内存和时间
- -Pe
- Show errors encountered when parsing MIB
files. These include references to IMPORTed modules and MIB objects that cannot
be located in the MIB directory search list. This can also be set with the
configuration token showMibErrors.
# 注释 ：-Pe 表示在解释 MIB
文件时显示错误。包括 IMPORTed 错误（重复加载）和 无法在 MIB 目录中找到指定对象
# 注释 ：可以在配置文件中用 showMibErrors
关键字来默认启用
# 问题 ：在 snmp.conf 中使用
showMibErrors
- -PR
- If the same MIB object
(parent name and sub-identifier) appears multiple times in the list of MIB
definitions loaded, use the last version to be read in. By default, the first
version will be used, and any duplicates discarded. This behaviour can
also be set with the configuration token mibReplaceWithLatest.
-
Such ordering is normally only relevant if
there are two MIB files with conflicting object definitions for the same OID (or
different revisions of the same basic MIB object).
-
# 注释 ：默认情况下，如果 Net-SNMP 在加载 MIB
时发现 一个 MIB 对象在列表上出现多次，则默认只加载第一个。
# -PR
则表示只加载最后一个。该行为可以在 snmp.conf 中用 mibReplaceWithLatest 来指定
- -Pu
- Allow the underline character in MIB object
names and other symbols. Strictly speaking, this is not valid SMI syntax, but
some vendor MIB files define such names. This can also be set with the
configuration token mibAllowUnderline.
# 注释 ：-Pu 允许 MIB 对象的名称和其他
symbol 中存在下划线。严格来说，这不是有效的 SMI 语法
# 该选项等同于 snmp.conf
中的 mibAllowUnderline
- -Pw
- Show various warning messages in parsing MIB
files and building the overall OID tree. This can also be set with the
configuration directive mibWarningLevel 1
# 注释 ：-Pw 表示在解释
MIB 文件和构建全局的 OID 树时显示错误。
# 该选项等同于 snmp.conf
的 mibWarningLevel 1
- -PW
- Show some additional warning messages,
mostly relating to parsing individual MIB objects. This can also be set with the
configuration directive mibWarningLevel 2
-
- # 注释 ：-PW
显示额外的告警信息，大部分还是和解析单个的 MIB 对象有关。
-
- # 这等同于 snmp.conf 中的
mibWarningLevel 2
OUTPUT OPTIONS
The format of the output from SNMP commands
can be controlled using various parameters of the -O flag. The effects of
these sub-options can be seen by comparison with the following default output
(unless otherwise specified):
# 注释 ：输出格式方面可以使用 -O
选项来控制
$ snmpget -c public -v 1 localhost sysUpTime.0
SNMPv2-MIB::sysUpTime.0 = Timeticks: (14096763) 1 day, 15:09:27.63
- -Oa
- Display string values as ASCII strings
(unless there is a DISPLAY-HINT defined for the corresponding MIB object). By
default, the library attempts to determine whether the value is a printable or
binary string, and displays it accordingly.
#
注释
： 默认情况下，snmp 在输出时会尝试判断值的类型是 ASCII 还是二进制字符。-Oa 则强制为 ASCII 输出
-
This option does not affect objects that
do have a Display Hint.
- -Ob
- Display table indexes numerically, rather
than trying to interpret the instance subidentifiers as string or OID values:
# 注释 ：-Ob
表示在输出表的记录的时候，index 采用数字方式而不是字符串方式
-
$ snmpgetnext -c public -v 1 localhost vacmSecurityModel
SNMP-VIEW-BASED-ACM-MIB::vacmSecurityModel.0."wes" = xxx
$ snmpgetnext -c public -v 1 -Ob localhost vacmSecurityModel
SNMP-VIEW-BASED-ACM-MIB::vacmSecurityModel.0.3.119.101.115 = xxx
- -Oe
- Removes the symbolic labels from enumeration
values:
$ snmpget -c public -v 1 localhost ipForwarding.0
IP-MIB::ipForwarding.0 = INTEGER: forwarding(1)
$ snmpget -c public -v 1 -Oe localhost ipForwarding.0
IP-MIB::ipForwarding.0 = INTEGER: 1
- -OE
- Modifies index strings to escape the quote
characters:
$ snmpgetnext -c public -v 1 localhost vacmSecurityModel
SNMP-VIEW-BASED-ACM-MIB::vacmSecurityModel.0."wes" = xxx
$ snmpgetnext -c public -v 1 -OE localhost vacmSecurityModel
SNMP-VIEW-BASED-ACM-MIB::vacmSecurityModel.0.\"wes\" = xxx
- This allows the output to be reused in shell
commands.
- -Of
- Include the full list of MIB objects when
displaying an OID:
- .iso.org.dod.internet.mgmt.mib-2.system.sysUpTime.0 =
- Timeticks: (14096763) 1 day,
15:09:27.63
# 注释 ：-Of 表示在输出 oid 时显示完整的
oid ，这个选项比较有用
- -On
- Displays the OID numerically:
.1.3.6.1.2.1.1.3.0 = Timeticks: (14096763) 1 day, 15:09:27.63
# 注释 ：-On 表示显示数字格式的 oid
，而不是字符串格式
# 注释 ：注意，如果使用 -Of 则覆盖 -On
- -Oq
- Removes the equal sign and type information
when displaying varbind values: SNMPv2-MIB::sysUpTime.0 1:15:09:27.63
# 注释 ：-Oq 表示输出时不包含 =
号和值的类型
- -OQ
- Removes the type information when displaying
varbind values: SNMPv2-MIB::sysUpTime.0 = 1:15:09:27.63
# 注释 ：-OQ 表示输出时不包含值的类型，但包含 =
号
- -Os
- Display the MIB object name (plus any
instance or other subidentifiers): sysUpTime.0 = Timeticks: (14096763) 1 day,
15:09:27.63
# 注释 ：-Os 表示输出时显示对象名和实例名，但不包含
MIB 名称
- -OS
- Display the name of the MIB, as well as the
object name: SNMPv2-MIB::sysUpTime.0 = Timeticks:
(14096763) 1 day, 15:09:27.63
# 注释 ：-OS 表示输出时按
“ MIB名称：对象名称：实例”的格式，
- This is the default OID output format.
# 注释 ：同时这也是默认的格式
- -Ot
- Display TimeTicks values as raw numbers:
SNMPv2-MIB::sysUpTime.0 = 14096763
# 注释 ：-Ot
表示在输出时间戳时按原始格式输出，也就是一串数字，而不是翻译成
# human-readable 的格式
- -OT
- If values are printed as Hex strings,
display a printable version as well.
# 注释 ：-OT 表示如果值是以16进制格式输出，则显示一个可打印的版本
- -Ou
- Display the OID in the traditional UCD-style
(inherited from the original CMU code). That means removing a series of
"standard" prefixes from the OID, and displaying the remaining list of MIB
object names (plus any other subidentifiers): system.sysUpTime.0 = Timeticks:
(14096763) 1 day, 15:09:27.63
# 注释 ：-Ou 表示输出 OID 时按照传统的 UCD 风格输出。这意味着去掉标准的前缀，只显示剩下的部分# 例如上面的粗体部分
- -OU
- Do not print the UNITS suffix at the end of
the value.
# 注释 ：-OU 表示在值的结尾不输出单位
- -Ov
- Display the varbind value only, not the OID:
# 注释 ：-Ov 表示只输出 oid 的类型和值，不包含
oid
$ snmpget -c public -v 1 -Oe localhost ipForwarding.0
INTEGER: forwarding(1)
- -Ox
- Display string values as Hex strings (unless
there is a DISPLAY-HINT defined for the corresponding MIB object). By default,
the library attempts to determine whether the value is a printable or binary
string, and displays it accordingly.
This option does not affect objects that
do have a Display Hint.
- # 注释 ：-Ox 表示限制 oid 的值时以 16 进制的格式输出，默认是自动判断输出的格式。
- -OX
- Display table indexes in a more "program
like" output, imitating a traditional array-style index format:
$ snmpgetnext -c public -v 1 localhost ipv6RouteTable
IPv6-MIB::ipv6RouteIfIndex.63.254.1.0.255.0.0.0.0.0.0.0.0.0.0.0.64.1 = INTEGER: 2
$ snmpgetnext -c public -v 1 -OE localhost ipv6RouteTable
IPv6-MIB::ipv6RouteIfIndex[3ffe:100:ff00:0:0:0:0:0][64][1] = INTEGER: 2
Most of these options can also be configured
via configuration tokens. See the (5) manual page for details.
# 注释 ：-OX 表示让输出看起来更加象程序的输出
# 注释 ：上面的这些选项大部分可以通过 snmp.conf
来配置
LOGGING OPTIONS
The mechanism and destination to use for
logging of warning and error messages can be controlled by passing various
parameters to the -L flag.
# 注释 ：日志的格式和方案可以通过 -L
选项控制
- -Le
- Log messages to the standard error stream.
# 注释 ：-Le
表示输出到标准错误
- -Lf FILE
- Log messages to the specified file.
# 注释 ：-Lf
表示输出到文件
- -Lo
- Log messages to the standard output
stream.
-
# 注释 ：-Lo
表示输出到标准输出
- -Ls FACILITY
- Log messages via syslog, using the specified
facility ('d' for LOG_DAEMON, 'u' for LOG_USER, or '0'-'7' for LOG_LOCAL0
through LOG_LOCAL7).
# 注释 ：-ls
表示通过 syslog ，d 表示 LOG_DAEMON ,u 表示 LOG_USER ，0-7 表示通过 LOG_LOCAL0 到 LOG_LOCAL
7
There are also "upper case" versions of each
of these options, which allow the corresponding logging mechanism to be
restricted to certain priorities of message. Using standard error logging as an
example:
-LE pri
- will log messages of priority 'pri' and
above to standard error.
- -LE p1-p2
- will log messages with priority between 'p1'
and 'p2' (inclusive) to standard error.
For -LF and -LS the priority
specification comes before the file or facility token. The priorities recognised
are:
- 0 or ! for LOG_EMERG,
1 or a for LOG_ALERT, 2 or c for LOG_CRIT, 3
or e for LOG_ERR, 4 or w for LOG_WARNING, 5 or
n for LOG_NOTICE, 6 or i for LOG_INFO, and 7 or
d for LOG_DEBUG.
Normal output is (or will be!) logged at a
priority level of LOG_NOTICE
INPUT
OPTIONS
The interpretation of input object names
and the values to be assigned can be controlled using various parameters of the
-I flag. The default behaviour will be described at the end of this
section.
# 注释 ：对输入的对象名称进行解释，因此 Net-SNMP
所赋予的值可以通过 -I 选项来控制
- -Ib
- specifies that
the given name should be regarded as a regular expression, to match
(case-insensitively) against object names in the MIB tree. The "best" match will be used -
calculated as the one that matches the closest to the beginning of the node name
and the highest in the tree. For example, the MIB object
vacmSecurityModel could be matched by the expression vacmsecuritymodel (full
name, but different case), or vacm.*model (regexp pattern).
-
Note that '.' is
a special character in regular expression patterns, so the expression cannot
specify instance subidentifiers or more than one object name. A
"best match" expression will only be applied against single MIB object names.
For example, the expression sys*ontact.0 would not match the instance
sysContact.0 (although sys*ontact would match sysContact). Similarly,
specifying a MIB module name will not succeed (so SNMPv2-MIB::sys.*ontact
would not match either).
-
# 注释 ：-Ib 表示对象名是一个正则表达式。由于 "."
在正则表达式是一个特殊的字符，所以 -Ib 无法匹配那些带有实例或者子数的 oid ，例如 sysContact.0
，
- -Ih
- disables the use of DISPLAY-HINT information
when assigning values. This would then require providing the raw value: snmpset
... HOST-RESOURCES-MIB::hrSystemData.0 x "07 D2 0C 0A 02 04 06 08" instead of a
formatted version: snmpset ... HOST-RESOURCES-MIB::hrSystemDate.0 =
2002-12-10,2:4:6.8
- -Ir
- disables checking table indexes and the
value to be assigned against the relevant MIB definitions. This will (hopefully)
result in the remote agent reporting an invalid request, rather than checking
(and rejecting) this before it is sent to the remote agent. Local checks are
more efficient (and the diagnostics provided also tend to be more precise), but
disabling this behaviour is particularly useful when testing the remote agent.
- -IR （重要）
- enables "random access" lookup of MIB names.
Rather than providing a full OID path to the desired MIB object (or qualifying
this object with an explicit MIB module name), the MIB tree will be searched for
the matching object name. Thus .iso.org.dod.internet.mib-2.system.sysDescr.0 (or
SNMPv2-MIB::sysDescr.0) can be specified simply as sysDescr.0.
-
- Warning:
- Since MIB object names are not globally
unique, this approach may return a different MIB object depending on which MIB
files have been loaded.
- The MIB-MODULE::objectName syntax has
the advantage of uniquely identifying a particular MIB object, as well as being
slightly more efficient (and automatically loading the necessary MIB file if
necessary).
# 注释 ：-IR 允许在查询 MIB 对象名称时
“随机访问“ ，而不是提供完整的 OID ，相反是对 MIB tree 进行搜索，查找是否有匹配的对象名称。
# 简单的说，就是不需要用户记住完整的 OID
，而是写出最后一部分，让 snmp 自己去 MIB tree 中查找是否存在该对象
# 这是一个很好的用的选项，不过因为 MIB
对象并不是全局唯一的，所以也有可能返回自己不想要的对象，这取决于那个 MIB 被加载
# 为了提高匹配的准确性，可以用
”mib：object“的格式
- -Is SUFFIX
- adds the specified suffix to each textual
OID given on the command line. This can be used to retrieve multiple objects
from the same row of a table, by specifying a common index value.
# 注释 ：-Is 表示对每个“文字格式”的 OID 都加上指定的后缀。你可以用它来查询一个表的同一行，
# 只需定一个公共的 index 就可以了
-IS PREFIX
-
- adds the specified prefix to each textual
OID given on the command line. This can be used to specify an explicit MIB
module name for all objects being retrieved (or for incurably lazy typists).
- # 注释 ：-IS 表示对每个文字格式的 OID 都加上前缀。
-Iu
-
- enables the traditional UCD-style approach
to interpreting input OIDs. This assumes that OIDs are rooted at the 'mib-2'
point in the tree (unless they start with an explicit '.' or include a MIB
module name). So the sysDescr instance above would be referenced as
system.sysDescr.0.
# 注释 ：-Iu 表示允许使用传统的 UCD 风格来解释
OID
# 所谓传统的 UCD 风格就是 ：假设 OID 从
mib-2 这个 subtree 开始（除非 oid 是以 '.' 开始），所以 sysDescr 可以写成
system.sysDescr.0
# 这也是一个方便用户的选项，可以节省书写一部分 oid
Object names specified with a leading '.' are
always interpreted as "fully qualified" OIDs, listing the sequence of MIB
objects from the root of the MIB tree. Such objects and those qualified by an
explicit MIB module name are unaffected by the -Ib, -IR and
-Iu flags.
# 注释 ：对于那些以 '.' 开头的 oid
，一律认为是从根开始，对于这种格式的 oid ，-Iu ，-IR，-Ib 不起作用
Otherwise, if none of the above input options
are specified, the default behaviour for a "relative" OID is to try and
interpret it as an (implicitly) fully qualified OID, then apply "random access"
lookup (-IR), followed by "best match" pattern matching
(-Ib).
# 注释 ：默认情况下，如果没有任何 -I 选项，则 oid
被首先认为是一个完整的 oid ，其次才是随机查找(-IR),然后才是 -Ib
ENVIRONMENT
VARIABLES
- PREFIX
- The standard prefix for object identifiers
(when using UCD-style output). Defaults to .iso.org.dod.internet.mgmt.mib-2
# 注释 ：PREFIX 是一个 OID 的标准前缀，默认是 .iso.org.dod.internet.mgmt.mib-2
# 通过定义该选项，可以在输入一个 OID 时不需要输出 PFEFIX 所指定的部分
-
- MIBS
- The list of MIBs to load. Defaults to
SNMPv2-TC:SNMPv2-MIB:IF-MIB:IP-MIB:TCP-MIB:UDP-MIB:SNMP-VACM-MIB. Overridden by
the -m option.
# 注释 ：MIBS 定义要加载的 MIB 列表。默认是： SNMPv2-TC:SNMPv2-MIB:IF-MIB:IP-MIB:TCP-MIB:UDP-MIB:SNMP-VACM-MIB.
# 注意，它会被命令行的 -m 选项的值所覆盖
-
- MIBDIRS
- The list of directories to search for MIBs.
Defaults to /usr/share/snmp/mibs. Overridden by the -M
option.
- # 注释 ：MIBDIRS 定义用于搜索可能存在的 MIB 文件的目录。默认是 /usr/share/snmp/mibs
FILES
- /etc/snmp/snmpd.conf
- Agent configuration file. See (5).
- /etc/snmp/snmp.conf
- ~/.snmp/snmp.conf
- Application configuration files. See (5).
SEE ALSO
(1), (1), (1), (1), (1), (1), (1), (1), (1), (1), (1), (1), (1), (1), (5).
