УПРАВЛЕНИЕ ЛОКАЛЬНЫМИ СЕТЯМИ Simple Network Management Protocol SNMP

УПРАВЛЕНИЕ ЛОКАЛЬНЫМИ СЕТЯМИ Simple Network Management Protocol SNMP

Модель ‘менеджер-агент’ для реализации системы управления

Пример управляемой конфигурации распределенной сети

SNMP

Версии SNMP • Три версии используются на сегодняшний день: – SNMPv 1 (1990) – SNMPv 2 c (1996) • Adds “Get. Bulk” function and some new types • Adds RMON (remote monitoring) capability – SNMPv 3 (2002) • SNMPv 3 started from SNMPv 1 (and not SNMPv 2 c) • Addresses security • Все версии полностью жизнеспособны • Множество SNMP агентов и менеджеров поддерживают все три версии протокола.

SNMP • Мониторинг сети и сбор информации GET: What is in your routing table?

SNMP • Конфигурирование сети SET: Add a route to your routing table

SNMP • Исключительные ситуации TRAP or INFORM: HELP!!!!

Форматы сообщений SNMP Version Community SNMP PDU (a) SNMP message request PDU 0 0 variablebindings type id (b) Get. Request PDU, Get. Next. Request PDU, and Set. Request PDU request error type id status (c) Get. Response PDU error index variablebindings PDU entertype prise (d) Trap PDU agent addr generic specific trap time stamp variablebindings name 1 name 2 value 2 name. N value 1 (e) variablebindings . . . 9

Последовательности SNMP PDU Manager Agent Get. Requ est PDU DU nse P spo Get. Re Agent Set. Requ est PDU onse t. Resp Ge Agent Get. Next Reques t PDU U se PD espon t. R Ge (b) Get next values (a) Get values Manager Agent Trap PDU (c) Set values (d) Send trap 10

SNMP v 2 Managed Configuration

Организация управляемых объектов

MIB – Management Information Base • MIB Breakdown… - OBJECT-TYPE - SYNTAX - ACCESS - STATUS - DESCRIPTION - String that describes the MIB object. Object IDentifier (OID). - Defines what kind of info is stored in the MIB object. - READ-ONLY, READ-WRITE. - State of object in regards the SNMP community. - Reason why the MIB object exists. Standard MIB Object: sys. Up. Time OBJECT-TYPE SYNTAX Time-Ticks ACCESS read-only STATUS mandatory DESCRIPTION “Time since the network management portion of the system was last reinitialised. : : = {system 3}

MIB – Management Information Base iso(1) • Object IDentifier (OID) 1 org(3) 3 - Example. 1. 3. 6. 1. 2. 1. 1 - iso(1) org(3) dod(6) internet(1) mgmt(2) mib-2(1) system(1) dod(6) 6 internet(1) 1 4 directory(1) 1 2 mgmt(2) experimental(3) 3 mib-2(1) Note: -. 1. 3. 6. 1 ~100% present. - mgmt and private most common. - MIB-2 successor to original MIB. - STATUS ‘mandatory’, All or nothing in group private(4) 1 system(1) tcp(6) 6 1 interfaces(2) 2 ip(4) 4

MIB – Management Information Base • system(1) group - Содержит объекты, которые описывают некоторую основную информацию о вершине. mib-2(1) 1 system(1) 1 2 l interfaces(2) system(1) group objects - sys. Descr(1) - sys. Object. ID(2) - sys. Up. Time(3) - sys. Contact(4) Description of the entity. Vendor defined OID string. Time since net-mgt was last re-initialised. Name of person responsible for the entity.

MIB – Management Information Base MIB - tree view MIB - syntax view mib-2(1) 1 system(1) 1 sys. Contact(3) 4 sys. Up. Time(3) sys. Desc(1) 1 sys. Object. ID(2) 2 3 sys. Up. Time OBJECT-TYPE SYNTAX INTEGER ACCESS read-only STATUS mandatory DESCRIPTION “The time (in hundredths of a second) since the network management portion of the system was last re-initialized. ” : : = {system 3}