Standards for Network Administration

1. Standards for Network Administration Week-5

2. Standards for Network Administration • Management Information Base • A structured database about a network unit • Structure for Management Information • Abstract Syntax Notation • Simple Network Management Protocol • SNMP Agents • Network Management System

3. Network Management System

4. Management Information Base • Data about a network units • 2 versions • MIB 1 (not used anymore) • MIB 2 • Structure defined using SMI • Object ID for each data item or collection • SMI written using ASN.1

5. Global SMI tree

6. System Group • Documentary info about a system unit • sysDescr – text string represnting the object (1) • sysObjectID – type number set by supplier (2) • sysUpTime – time since booted 10-2Sec (3) • sysContact – name of responsible person (4) • sysName – a Name for the unit (5) • sysLocation – where to find the unit (6) • sysService – States the OSI operational layer (7)as sum of powers eg 2layer2-1+2layer3-1 = 21+22 = 6

7. Interfaces Group • For each network card • Type • Operational status • Speed • Etc

8. ICMP Group • Packet counts • Error counts • Useful for network monitoring…

9. MIB • Forms an extensive tree structure • Every object becomes filled with data • Either from system administrator • Or collected by devices themselvesduring operation of network • The NMS console gathers and presents this data for user/administrator

10. SNMP • The protocol that allows communication between network components (via agents) and MIB • Uses UDP transport protocol port 160/161 • Several versions • SNMP v1 – poll only, plaintext community • SNMP v2 –Added Trap & getBlock • SNMP v3 – Authentication, Privacy, Discovery (from other SNMP engines), Key Management

11. RMON • An extension of MIB2 • RMON1 appeared in 1995 • Replaced by RMON-II soon afterward • Uses Probes instead of Agents • Why develop RMON? • MIB2/SNMP Polling is strain on network • Lost connection while polling also loses data! • RMON agents operate independantly • Data can be downloaded to MIB later • Lost connections don’t interrupt data gathering

12. SMI tree for RMON

13. Statistics History Alarm If threshold exceeded Host Stats about MAC addrs HostTopN List of top MAC addrs Matrix traffic between units Filter Used to drop packets Packet Capture Copy of selected pkts Event Produce/Store events TokenRing Ten RMON groups

14. RMON-II • RMON1 – Only Layer 2 operation • RMON II can also operate in Layer 3 • Includes Routers and WAN connections • Is able to monitor TCP ports • Monitor traffic by Application eg HTTP port 80 • Can therefore class traffic by application type

15. RMON-II SMI tree

16. RMON-III and SMON • New standards proposed • RMON-III will include WAN objects • SMON • for monitoring switched traffic • VLANs • IETF RFC 2613 / RFC2613 “ Remote Network Monitoring MIB Extensions for Switched Networks Version 1.0”

17. SMON • There are several issues in monitoring switched networks that are different from monitoring frame-based networks. • First, data in switched networks are connection oriented and a single monitor cannot capture data by listening to broadcasts as in frame-based networks. • Second, monitoring end-to-end in a switched network requires many resources. There must be some ways to aggregate the data determined by the management applications. • Third, virtual switched networks must also be considered such as VLAN. • Fourth, packet prioritization exists in swtiched network. • Fifth, SMON focuses on packet monitoring in high layer of the network instead of cells in lower layer. • SMON sees three different kinds of data sources: RMON data source, VLAN data source, and physical data source. • RMON data source is defined to be compatible with RMON, VLAN data source is defined to include virtual data source created by VLAN. All other data sources are grouped into physical data source