Access Point Registration Table

Таблица уровней клиентов для точек доступа Cisco

Задача

Собирать данные о траффике и уровне сигнала с точек доступа

• Клиенты динамические, их мак-адреса заранее не известны
• SSID добавляются и удаляются по мере необходимости
• Точки могут иметь как один интерфейс так и два

Для того что бы получить информацию по SNMP о клиентах подключенных к точке доступа, существует специальный MIB CISCO-DOT11-ASSOCIATION-MIB
Он доступен достаточно давно, как минимум он работает на точках 1200 и 1100 серий, ну и на более современных тоже.

Просмотр OID

Пример с использованием display-hint

# snmpwalk -v2c -c MON 192.168.77.2  .1.3.6.1.4.1.9.9.273.1.3.1   -OX

CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientCurrentTxRateSet[1]["450"][STRING: da:20:60:64:36:95] = Hex-STRING: 07
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientCurrentTxRateSet[2]["450"][STRING: a4:45:19:5a:ef:48] = Hex-STRING: 01
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientUpTime[1]["450"][STRING: da:20:60:64:36:95] = Gauge32: 15898 second
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientUpTime[2]["450"][STRING: a4:45:19:5a:ef:48] = Gauge32: 425 second
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientSignalStrength[1]["450"][STRING: da:20:60:64:36:95] = INTEGER: -64 dBm
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientSignalStrength[2]["450"][STRING: a4:45:19:5a:ef:48] = INTEGER: -89 dBm
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientSigQuality[1]["450"][STRING: da:20:60:64:36:95] = Gauge32: 24 percentage
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientSigQuality[2]["450"][STRING: a4:45:19:5a:ef:48] = Gauge32: 9 percentage
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientAgingLeft[1]["450"][STRING: da:20:60:64:36:95] = Gauge32: 58 second
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientAgingLeft[2]["450"][STRING: a4:45:19:5a:ef:48] = Gauge32: 34 second
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientPacketsReceived[1]["450"][STRING: da:20:60:64:36:95] = Counter32: 149529 packet
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientPacketsReceived[2]["450"][STRING: a4:45:19:5a:ef:48] = Counter32: 346 packet
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientBytesReceived[1]["450"][STRING: da:20:60:64:36:95] = Counter32: 23101125 byte
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientBytesReceived[2]["450"][STRING: a4:45:19:5a:ef:48] = Counter32: 113287 byte
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientPacketsSent[1]["450"][STRING: da:20:60:64:36:95] = Counter32: 617733 packet
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientPacketsSent[2]["450"][STRING: a4:45:19:5a:ef:48] = Counter32: 251 packet
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientBytesSent[1]["450"][STRING: da:20:60:64:36:95] = Counter32: 745190393 byte
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientBytesSent[2]["450"][STRING: a4:45:19:5a:ef:48] = Counter32: 47693 byte
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientDuplicates[1]["450"][STRING: da:20:60:64:36:95] = Counter32: 2389 packet
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientDuplicates[2]["450"][STRING: a4:45:19:5a:ef:48] = Counter32: 12 packet
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientMsduRetries[1]["450"][STRING: da:20:60:64:36:95] = Counter32: 159859 packet
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientMsduRetries[2]["450"][STRING: a4:45:19:5a:ef:48] = Counter32: 331 packet
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientMsduFails[1]["450"][STRING: da:20:60:64:36:95] = Counter32: 0 packet
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientMsduFails[2]["450"][STRING: a4:45:19:5a:ef:48] = Counter32: 0 packet
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientWepErrors[1]["450"][STRING: da:20:60:64:36:95] = Counter32: 0 packet
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientWepErrors[2]["450"][STRING: a4:45:19:5a:ef:48] = Counter32: 0 packet
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientMicErrors[1]["450"][STRING: da:20:60:64:36:95] = Counter32: 0 error
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientMicErrors[2]["450"][STRING: a4:45:19:5a:ef:48] = Counter32: 0 error
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientMicMissingFrames[1]["450"][STRING: da:20:60:64:36:95] = Counter32: 0 packet
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientMicMissingFrames[2]["450"][STRING: a4:45:19:5a:ef:48] = Counter32: 0 packet

Или без использования

# snmpwalk -v2c -c MON 192.168.77.2  .1.3.6.1.4.1.9.9.273.1.3.1   -On

.1.3.6.1.4.1.9.9.273.1.3.1.1.1.1.3.52.53.48.218.32.96.100.54.149 = Hex-STRING: 05
.1.3.6.1.4.1.9.9.273.1.3.1.1.1.2.3.52.53.48.164.69.25.90.239.72 = Hex-STRING: 01
.1.3.6.1.4.1.9.9.273.1.3.1.1.2.1.3.52.53.48.218.32.96.100.54.149 = Gauge32: 15911 second
.1.3.6.1.4.1.9.9.273.1.3.1.1.2.2.3.52.53.48.164.69.25.90.239.72 = Gauge32: 439 second
.1.3.6.1.4.1.9.9.273.1.3.1.1.3.1.3.52.53.48.218.32.96.100.54.149 = INTEGER: -63 dBm
.1.3.6.1.4.1.9.9.273.1.3.1.1.3.2.3.52.53.48.164.69.25.90.239.72 = INTEGER: -89 dBm
.1.3.6.1.4.1.9.9.273.1.3.1.1.4.1.3.52.53.48.218.32.96.100.54.149 = Gauge32: 31 percentage
.1.3.6.1.4.1.9.9.273.1.3.1.1.4.2.3.52.53.48.164.69.25.90.239.72 = Gauge32: 10 percentage
.1.3.6.1.4.1.9.9.273.1.3.1.1.5.1.3.52.53.48.218.32.96.100.54.149 = Gauge32: 58 second
.1.3.6.1.4.1.9.9.273.1.3.1.1.5.2.3.52.53.48.164.69.25.90.239.72 = Gauge32: 51 second
.1.3.6.1.4.1.9.9.273.1.3.1.1.6.1.3.52.53.48.218.32.96.100.54.149 = Counter32: 149587 packet
.1.3.6.1.4.1.9.9.273.1.3.1.1.6.2.3.52.53.48.164.69.25.90.239.72 = Counter32: 347 packet
.1.3.6.1.4.1.9.9.273.1.3.1.1.7.1.3.52.53.48.218.32.96.100.54.149 = Counter32: 23109939 byte
.1.3.6.1.4.1.9.9.273.1.3.1.1.7.2.3.52.53.48.164.69.25.90.239.72 = Counter32: 113333 byte
.1.3.6.1.4.1.9.9.273.1.3.1.1.8.1.3.52.53.48.218.32.96.100.54.149 = Counter32: 618046 packet
.1.3.6.1.4.1.9.9.273.1.3.1.1.8.2.3.52.53.48.164.69.25.90.239.72 = Counter32: 251 packet
.1.3.6.1.4.1.9.9.273.1.3.1.1.9.1.3.52.53.48.218.32.96.100.54.149 = Counter32: 745583754 byte
.1.3.6.1.4.1.9.9.273.1.3.1.1.9.2.3.52.53.48.164.69.25.90.239.72 = Counter32: 47693 byte
.1.3.6.1.4.1.9.9.273.1.3.1.1.10.1.3.52.53.48.218.32.96.100.54.149 = Counter32: 2392 packet
.1.3.6.1.4.1.9.9.273.1.3.1.1.10.2.3.52.53.48.164.69.25.90.239.72 = Counter32: 12 packet
.1.3.6.1.4.1.9.9.273.1.3.1.1.11.1.3.52.53.48.218.32.96.100.54.149 = Counter32: 159964 packet
.1.3.6.1.4.1.9.9.273.1.3.1.1.11.2.3.52.53.48.164.69.25.90.239.72 = Counter32: 331 packet
.1.3.6.1.4.1.9.9.273.1.3.1.1.12.1.3.52.53.48.218.32.96.100.54.149 = Counter32: 0 packet
.1.3.6.1.4.1.9.9.273.1.3.1.1.12.2.3.52.53.48.164.69.25.90.239.72 = Counter32: 0 packet
.1.3.6.1.4.1.9.9.273.1.3.1.1.13.1.3.52.53.48.218.32.96.100.54.149 = Counter32: 0 packet
.1.3.6.1.4.1.9.9.273.1.3.1.1.13.2.3.52.53.48.164.69.25.90.239.72 = Counter32: 0 packet
.1.3.6.1.4.1.9.9.273.1.3.1.1.14.1.3.52.53.48.218.32.96.100.54.149 = Counter32: 0 error
.1.3.6.1.4.1.9.9.273.1.3.1.1.14.2.3.52.53.48.164.69.25.90.239.72 = Counter32: 0 error
.1.3.6.1.4.1.9.9.273.1.3.1.1.15.1.3.52.53.48.218.32.96.100.54.149 = Counter32: 0 packet
.1.3.6.1.4.1.9.9.273.1.3.1.1.15.2.3.52.53.48.164.69.25.90.239.72 = Counter32: 0 packet

Разбор OID

Как можно видеть, сам OID состоит из нескольких частей Для определенности рассмотрим уровни сигнала:

.1.3.6.1.4.1.9.9.273.1.3.1.1.3.1.3.52.53.48.218.32.96.100.54.149 = INTEGER: -63 dBm
.1.3.6.1.4.1.9.9.273.1.3.1.1.3.2.3.52.53.48.164.69.25.90.239.72 = INTEGER: -89 dBm

CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientSignalStrength[1]["450"][STRING: da:20:60:64:36:95] = INTEGER: -64 dBm
CISCO-DOT11-ASSOCIATION-MIB::cDot11ClientSignalStrength[2]["450"][STRING: a4:45:19:5a:ef:48] = INTEGER: -89 dBm

Часть .1.3.6.1.4.1.9.9.273.1.3.1.1.3 это и есть OID CISCO-DOT11-ASSOCIATION и она общая Далее в самом OID закодировано значение "кому принадлежит сигнал", т е какому клиенту

Выделенное значение и его описание:

• 2.3.52.53.48.164.69.25.90.239.72 - номер интерфейса, он же ifIndex, dot11Radio0 (1), или dot11Radio1 (2), в примере клиент подключен к 5Ghz интерфейсу (dot11Radio1)
• 2.3.52.53.48.164.69.25.90.239.72 - Длинна SSID в байтах, в пример 3 символа (SSID в примере "450")
• 2.3.52.53.48.164.69.25.90.239.72 - коды ASCII символов SSID, их три - "450"
• 2.3.52.53.48.164.69.25.90.239.72 - мак-адрес, 6 байт, записаны в деятичной форме, "a4:45:19:5a:ef:48", например 164(десятичное) = a4(hex), 69(десятичное) = 45 (hex) и так далее.