Networking: Monitoring

SNMP:

https://www.youtube.com/watch?v=HXu0Ifj0oWU

SNMP components:

• SNMP agent: running on the network device
• MIB: is the structure which contains variables. Each variable is identified as OID. eg: CPU, interface status will have OID
  • OID are in hierarchical structure. http://www.oid-info.com/
  • SNMP manager will send OID to the agent and agent will response back
• SNMP manager: the SNMP server

SNMP Versions:

1. SNMP V1:
2. SNMP v2c: c is the community or password. v2c also added bulk get so we can get information about multiple OID
3. SNMP v3: supports encryption and authentication

SNMP message types:

1. Read: Send by the SNMP manager to get info about SNMP agent:
   • it has 3 messages:
     • get
     • getnext
     • getbulk
2. write
3. Notification:
   • Trap: send by the agent to the manager. no ack will be send by the manager back to the agent. AS SNMP is UDP, these messages are unreliable.
   • Inform: same as trap but ack will be send by the manager. Again its UDP.

gMNI

https://www.youtube.com/watch?v=psj4KeCWuOc