3.2 - Network Solutions

Network discovery

• Difficult to see beyond the wall jack

– LLDP (Link Layer Discovery Protocol),

– CDP (Cisco Discovery Protocol), etc.

– IP scanners (Nmap)

– Commercial network scanners

– SNMP

• Ad hoc

– Scan as needed or required

• Scheduled

– Scan occurs at regular intervals

– Report on moves, adds, and changes

Traffic analysis

• View traffic information from routers, switches,

firewalls, etc.

– Identify traffic flows

– View traffic summaries

• Can be very detailed

– Every flow from every device

– Important historical information

• Monitoring, post-event analysis

Performance monitoring

• The fundamental network statistic

– Amount of network use over time

• Many different ways to gather this metric

– SNMP, NetFlow, sFlow, IPFIX protocol analysis,

software agent

• Identify fundamental issues

– Nothing works properly if bandwidth is highly utilized

Availability monitoring

• Up or down

– The most important statistic

– No special rights or permissions required

– Green is good, red is bad

• Alarming and alerting

– Notification should an interface fail to report

– Email, SMS

• Short-term and long-term reporting

– View availability over time

– Not focused on additional details

– Additional monitoring may require SNMP

Network device backup and restore

• Every device has a configuration

– IP addresses, security settings, port configurations

– Most devices allow the configuration to be

downloaded and uploaded

– Configurations may be specific to a version of

operating code or firmware

• Revert to a previous state

– Use backups to return to a previous configuration

date and time

– May require a firmware or version downgrade

Configuration monitoring

• Ten identical web servers

– Should have ten identical configurations

– How to confirm?

• Monitor the configurations

– Verify consistency

– Alert on any changes

– Backup and restore

• Often part of a larger management system or strategy

– Central console and access