U2.5 SNMPv1

1. network mgt protocols provide
   1. configuration management
   2. accounting
   3. event logging
2. defines network mgt security in general

Attachments:

• U2.5 SNMPv1 - architectural model

1. at least one management station
   1. acts as management role
2. a number of network elements
   1. manages systems, iE routers, servers gateways
3. At least one agent

1. SNMP access MIB on top of UDP and IP

   Attachments:

   • U2.5 SNMPv1 - SNMPv1 protocol stack
   1. connectionless!!
   2. ports
      1. 161
         1. for requests (GET, SET)
      2. 162
         1. for traps
2. MIB Contains configuration and operational data

1. enables mgt station to retrieve object values from managed entity

1. enables the management station to set object values in managed entity

1. enables a managed entity to notify the management station of significant events
2. Traps are sent by NW entities when they want to inform the management station of some event

1. 3 parts to a PDU message
   1. version
   2. community
   3. SNMP operation

1. data modification of messages in transit
2. masquerade. as agent or mgmt device

1. message stream modification. recording or replay of messages
2. eavesdropping

1. reduced overhead
2. protocol simplicity

1. no inbuilt reliability
2. connection oriented operations must be built into upper layer applications

1. authentication service
   1. Assure the destination device that the SNMP PDU does come from the source from which it claims to be
2. access control service
   1. Limit the SNMP operations that a device can request according to device's identity
3. security mechanisms provided to implement these services based on idea of communities
   1. authentication mechanism
      1. community name
         1. All PDUs from mgt station must contain the community name
   2. access mode mechanism
      1. community profile
         1. Each device stores a community profile that specifies which MIB values and how those values can be access by an entity bearing the associated community name.