net-snmp（5.6.1） 编译 安装 运行调试全记录
net-snmp 5.6.1 代码下载编译安装的过程相对比较简单，而且有官方的Guide，在此不再重复叙述，ubuntu 12.04 32bits/64bits 按照下面这个Guide 都测试成功了。
http://www.net-snmp.org/wiki/index.php/Net-Snmp_on_Ubuntu
安装 $ sudo make install > install.log 可以查看一下snmpd mibs 文件的安装位置，不然还真不好找，这里一般都是安装到 /usr/local/ 下面了。
要想执行 snmpwalk/snmpget 等命令，首先需要在本机上启动 snmpd 服务，snmpd 这个服务启动的难点和关键就在于 snmpd.conf 配置文件，这里直接贴上我的可以运行的配置文件：
###############################################################################
#
# EXAMPLE.conf:
# An example configuration file for configuring the Net-SNMP agent ('snmpd')
# See the 'snmpd.conf(5)' man page for details
#
# Some entries are deliberately commented out, and will need to be explicitly activated
#
###############################################################################
#
# AGENT BEHAVIOUR
#
# Listen for connections from the local system only
#agentAddress udp:127.0.0.1:161
# Listen for connections on all interfaces (both IPv4 *and* IPv6)
#agentAddress udp:161,udp6:[::1]:161
# qiang added listen for connections on all interfaces, only for IPv4
agentAddress udp:161
###############################################################################
#
# SNMPv3 AUTHENTICATION
#
# Note that these particular settings don't actually belong here.
# They should be copied to the file /var/lib/snmp/snmpd.conf
# and the passwords changed, before being uncommented in that file *only*.
# Then restart the agent
# createUser authOnlyUser MD5 "remember to change this password"
# createUser authPrivUser SHA "remember to change this one too" DES
# createUser internalUser MD5 "this is only ever used internally, but still change the password"
# If you also change the usernames (which might be sensible),
# then remember to update the other occurances in this example config file to match.
###############################################################################
#
# ACCESS CONTROL
#
# system + hrSystem groups only
#view systemonly included .1.3.6.1.2.1.1
#view systemonly included .1.3.6.1.2.1.25.1
# added by qiang
view all included .1
# Full access from the local host
#rocommunity public localhost
# Default access to basic system info
# rocommunity public default -V systemonly
rocommunity public default -V all
# Full access from an example network
# Adjust this network address to match your local
# settings, change the community string,
# and check the 'agentAddress' setting above
#rocommunity secret 10.0.0.0/16
# Full read-only access for SNMPv3
rouser authOnlyUser
# Full write access for encrypted requests
# Remember to activate the 'createUser' lines above
#rwuser authPrivUser priv
# It's no longer typically necessary to use the full 'com2sec/group/access' configuration
# r[ou]user and r[ow]community, together with suitable views, should cover most requirements
###############################################################################
#
# SYSTEM INFORMATION
#
# Note that setting these values here, results in the corresponding MIB objects being 'read-only'
# See snmpd.conf(5) for more details
sysLocation Sitting on the Dock of the Bay
sysContact Me
# Application + End-to-End layers
sysServices 72
#
# Process Monitoring
#
# At least one 'mountd' process
proc mountd
# No more than 4 'ntalkd' processes - 0 is OK
proc ntalkd 4
# At least one 'sendmail' process, but no more than 10
proc sendmail 10 1
# Walk the UCD-SNMP-MIB::prTable to see the resulting output
# Note that this table will be empty if there are no "proc" entries in the snmpd.conf file
#
# Disk Monitoring
#
# 10MBs required on root disk, 5% free on /var, 10% free on all other disks
disk / 10000
disk /var 5%
includeAllDisks 10%
# Walk the UCD-SNMP-MIB::dskTable to see the resulting output
# Note that this table will be empty if there are no "disk" entries in the snmpd.conf file
#
# System Load
#
# Unacceptable 1-, 5-, and 15-minute load averages
load 12 10 5
# Walk the UCD-SNMP-MIB::laTable to see the resulting output
# Note that this table *will* be populated, even without a "load" entry in the snmpd.conf file
###############################################################################
#
# ACTIVE MONITORING
#
# send SNMPv1 traps
trapsink localhost public
# send SNMPv2c traps
#trap2sink localhost public
# send SNMPv2c INFORMs
#informsink localhost public
# Note that you typically only want *one* of these three lines
# Uncommenting two (or all three) will result in multiple copies of each notification.
#
# Event MIB - automatically generate alerts
#
# Remember to activate the 'createUser' lines above
iquerySecName internalUser
rouser internalUser
# generate traps on UCD error conditions
defaultMonitors yes
# generate traps on linkUp/Down
linkUpDownNotifications yes
###############################################################################
#
# EXTENDING THE AGENT
#
#
# Arbitrary extension commands
#
extend test1 /bin/echo Hello, world!
extend-sh test2 echo Hello, world! ; echo Hi there ; exit 35
#extend-sh test3 /bin/sh /tmp/shtest
# Note that this last entry requires the script '/tmp/shtest' to be created first,
# containing the same three shell commands, before the line is uncommented
# Walk the NET-SNMP-EXTEND-MIB tables (nsExtendConfigTable, nsExtendOutput1Table
# and nsExtendOutput2Table) to see the resulting output
# Note that the "extend" directive supercedes the previous "exec" and "sh" directives
# However, walking the UCD-SNMP-MIB::extTable should still returns the same output,
# as well as the fuller results in the above tables.
#
# "Pass-through" MIB extension command
#
#pass .1.3.6.1.4.1.8072.2.255 /bin/sh PREFIX/local/passtest
#pass .1.3.6.1.4.1.8072.2.255 /usr/bin/perl PREFIX/local/passtest.pl
# Note that this requires one of the two 'passtest' scripts to be installed first,
# before the appropriate line is uncommented.
# These scripts can be found in the 'local' directory of the source distribution,
# and are not installed automatically.
# Walk the NET-SNMP-PASS-MIB::netSnmpPassExamples subtree to see the resulting output
#
# AgentX Sub-agents
#
# Run as an AgentX master agent
master agentx
# Listen for network connections (from localhost)
# rather than the default named socket /var/agentx/master
#agentXSocket tcp:localhost:705
运行的时候注意需要sudo 权限，因为snmpd 需要用到161 UDP port, 需要root权限，否则会有如下提示：
$ snmpd -f -Lo -C -c ~/snmpd.conf
Turning on AgentX master support.
Error opening specified endpoint "udp:161"
Server Exiting with code 1
加上sudo 之后，正常启动，
$ sudo snmpd -f -Lo -C -c ~/snmpd.conf
Turning on AgentX master support.
NET-SNMP version 5.6.1
使用sockstat 查看端口状态：
$ sudo sockstat
USER PROCESS PID PROTO SOURCE ADDRESS FOREIGN ADDRESS STATE
root rpcbind 749 udp4 *:111 *:* CLOSED
root rpcbind 749 udp4 *:903 *:* CLOSED
root rpcbind 749 tcp4 *:111 *:* LISTEN
root sshd 856 tcp4 *:22 *:* LISTEN
root rpc.statd 875 udp4 127.0.0.1:627 *:* CLOSED
statd rpc.statd 875 udp4 *:35824 *:* CLOSED
statd rpc.statd 875 tcp4 *:49187 *:* LISTEN
root xinetd 1043 udp4 *:69 *:* CLOSED
root cupsd 1053 tcp4 127.0.0.1:631 *:* LISTEN
avahi avahi-daemon 1143 udp4 *:5353 *:* CLOSED
avahi avahi-daemon 1143 udp4 *:48954 *:* CLOSED
root rpc.mountd 1191 udp4 *:55068 *:* CLOSED
root rpc.mountd 1191 tcp4 *:60662 *:* LISTEN
root rpc.mountd 1191 udp4 *:56931 *:* CLOSED
root rpc.mountd 1191 tcp4 *:54234 *:* LISTEN
root rpc.mountd 1191 udp4 *:50313 *:* CLOSED
root rpc.mountd 1191 tcp4 *:36634 *:* LISTEN
root dhclient 1259 udp4 *:68 *:* CLOSED
root dnsmasq 1313 udp4 127.0.0.1:53 *:* CLOSED
root dnsmasq 1313 tcp4 127.0.0.1:53 *:* LISTEN
miredo miredo 1649 udp4 *:36362 *:* CLOSED
qiang dropbox 2128 udp4 *:17500 *:* CLOSED
qiang dropbox 2128 tcp4 *:17500 *:* LISTEN
qiang ubuntu-geoip-pr 2279 tcp4 128.224.162.198:37615 91.189.89.144:80 CLOSE_WAIT
qiang chromium-browse 2451 tcp4 128.224.162.198:56295 74.125.31.125:5222 ESTABLISHED
qiang chromium-browse 2451 tcp4 128.224.162.198:37246 173.194.34.67:443 ESTABLISHED
qiang chromium-browse 2451 tcp4 128.224.162.198:44171 117.79.157.251:80 ESTABLISHED
qiang chromium-browse 2451 tcp4 128.224.162.198:44165 117.79.157.251:80 ESTABLISHED
qiang thunderbird 3982 tcp4 128.224.162.198:43863 147.11.189.50:993 ESTABLISHED
qiang thunderbird 3982 tcp4 128.224.162.198:43875 147.11.189.50:993 ESTABLISHED
qiang thunderbird 3982 tcp4 128.224.162.198:43876 147.11.189.50:993 ESTABLISHED
qiang thunderbird 3982 tcp4 128.224.162.198:43877 147.11.189.50:993 ESTABLISHED
root snmpd 10529 udp4 *:161 *:* CLOSED
root snmpd 10529 udp4 *:46939 *:* CLOSED或是
$ netstat -an | grep 161
udp 0 0 0.0.0.0:161 0.0.0.0:*
这时，在另外一个Terminal 或是另外一台主机上执行：
$ snmpwalk -v 1 -c public -Cp localhost
就会输出正确的结果了。
参考文章：
http://blog.sina.com.cn/s/blog_8ea085de01012tdo.html
http://web.archiveorange.com/archive/v/WnPpSNSsl7HujziSGyP4
$ snmptranslate -On -Tp .1.3.6.1.2.1.1
+--system(1)
|
+-- -R-- String sysDescr(1)
| Textual Convention: DisplayString
| Size: 0..255
+-- -R-- ObjID sysObjectID(2)
+-- -R-- TimeTicks sysUpTime(3)
| |
| +--sysUpTimeInstance(0)
|
+-- -RW- String sysContact(4)
| Textual Convention: DisplayString
| Size: 0..255
+-- -RW- String sysName(5)
| Textual Convention: DisplayString
| Size: 0..255
+-- -RW- String sysLocation(6)
| Textual Convention: DisplayString
| Size: 0..255
+-- -R-- INTEGER sysServices(7)
| Range: 0..127
+-- -R-- TimeTicks sysORLastChange(8)
| Textual Convention: TimeStamp
|
+--sysORTable(9)
|
+--sysOREntry(1)
| Index: sysORIndex
|
+-- ---- INTEGER sysORIndex(1)
| Range: 1..2147483647
+-- -R-- ObjID sysORID(2)
+-- -R-- String sysORDescr(3)
| Textual Convention: DisplayString
| Size: 0..255
+-- -R-- TimeTicks sysORUpTime(4)
Textual Convention: TimeStamp
$ snmptranslate -IR -Tp |less
这个命令看整个 MIBs 树更直观
SNMP agent ：
http://blog.chinaunix.net/uid-790245-id-2037497.html
SNMP trap:
http://blog.chinaunix.net/uid-677314-id-83386.html
http://blog.chinaunix.net/uid-790245-id-2037495.html
SNMP v3
http://blog.chinaunix.net/uid-451-id-3337094.html