Simple Network Management Protocol (SNMP)
1. Core Concepts
Section titled “1. Core Concepts”| Term | Description |
|---|---|
| SNMP Manager (NMS) | Central server that collects data from network devices |
| SNMP Agent | Software running on the router/switch |
| MIB (Management Information Base) | Structured database on the device organizing all statistics (CPU, interface status, etc.) |
| OID (Object Identifier) | Specific address to look up a metric within the MIB |
| Traps | Unreliable/unacknowledged alerts from agent → manager (UDP 162) |
| Informs | Reliable alerts requiring manager acknowledgment |
2. Protocol Versions
Section titled “2. Protocol Versions”| Version | Security | Community Strings | Features |
|---|---|---|---|
| v1 | Clear text | Yes | Traps only |
| v2c | Clear text | Yes | Adds Informs, bulk transfers |
| v3 | Auth + Encryption (USM) | No (uses users) | Secure — SHA/MD5 auth, DES/AES privacy |
3. Configuration
Section titled “3. Configuration”3.1 SNMPv2c
Section titled “3.1 SNMPv2c”R1(config)# snmp-server community ReadOnlyPassword ROR1(config)# snmp-server community WritePassword RWR1(config)# snmp-server location Madrid_DataCenterR1(config)# snmp-server contact admin@networklab.comR1(config)# snmp-server host 10.0.0.100 version 2c WritePasswordR1(config)# snmp-server enable traps config3.2 SNMPv3
Section titled “3.2 SNMPv3”R1(config)# snmp-server group MySecureGroup v3 privR1(config)# snmp-server user SecurityAdmin MySecureGroup v3 auth sha MyAuthPass priv aes 128 MyPrivPass