study_admin_l5_snmp_part2
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- **Created on**: 2025-05-24 05:06:34
Lecture 7: SNMP Summary
Key Concepts
- SNMP: Protocol for managing network devices
- Components: Manager, Agent, MIB, SMI
- Versions: v1 (basic), v2c (improved), v3 (secure)
- Ports: 161 (requests), 162 (traps)
Review Questions & Answers
1. What are Management Information Bases?
Answer:
MIBs are databases storing manageable objects in devices.
Types:
- MIB I (114 objects)
- MIB II (185 objects)
- Vendor-specific MIBs
2. Define PDU types
Answer:
- GetRequest: Read data
- SetRequest: Change data
- Trap: Alarm message
- Inform: Trap with ack
(7 types in v2/v3 vs 5 in v1)
3. SNMP port numbers?
Answer:
- 161: Manager requests
- 162: Agent traps
4. SNMP security levels?
Answer:
- noAuthNoPriv (least secure)
- authNoPriv (auth only)
- authPriv (auth + encryption)
5. Configure read-only router?
Answer:
Router(config)#snmp-server community STRING ro
6. Why avoid RW configuration?
Answer:
RW allows device changes - security risk if compromised.
New Questions & Answers
1. What's the difference between SNMPv2c and v3?
Answer:
v3 adds encryption (authPriv) while v2c uses plaintext.
2. When would you use GetBulkRequest?
Answer:
For fetching large data chunks (only in v2/v3).
3. Why are traps useful?
Answer:
They alert managers immediately when issues occur.
4. What does SMI do?
Answer:
Defines rules for naming/encoding MIB objects.
5. Main weakness of SNMPv1?
Answer:
No encryption - uses plaintext community strings.
SNMP Cheat Sheet
| Version | Auth | Encryption | Ports |
|---|---|---|---|
| v1 | Community | No | 161/162 |
| v2c | Community | No | 161/162 |
| v3 | User+MD5/SHA | DES (opt) | 161/162 |
continue:./study_admin_l6_cmip.md
before:./study_admin_l4.md