1. Chapter 36 Network Management & SNMP

2. Network management monitors network related hardware & software; troubleshoot network problems Detects major failures – eg. total hardware failure, bogus routing entry intermittent failures difficult to detect and isolate – Eg.a bad NIC card may lead to many retransmissions, reducing available bandwidth to others network management software runs at layer 7 of the ISO 7-layer model client application program (manager) runs on network management computer Server process (agent) listens on UDP port 161 on network device

3. Simple Network Management Protocol defines format of manager requests and agent replies SNMP message is encoded using Abstract Syntax Notation (ASN.1) – Eg. to encode an integer, ASN.1 sends a pair of values: a length L followed by L octets that contain the integer SNMP uses fetch/store (get/set) paradigm – manager retrieves data from agent or sets an objects within the network device to a certain state Eg. MRTG

4. Management Information Base the set of all objects SNMP can access each object (MIB variable) is uniquely represented by a sequence of numbers corresponding to sequence of names – eg. 1.3.6.1.2.1.4.3 represents iso.org.dod.internet.mgmt.mib.ip.ipInReceives there are MIB variables for – protocols such as UDP, TCP, IP, ARP – hardware such as Ethernet, TokenRing, FDDI, bridge, switch – tables such as routing tables.