Network Management (Tools, Netflow, NBAR, IP SLA)

Monitoring and Managing

• Know your network is doing well.
• Understand the trends in your network performance.
• Identify your bottlenecks and propose solutions.
• Proact – Don’t react.

Phases of optimizations and the tools

1. Create a baseline – Netflow, NBAR, IP SLA
2. Optimize Network – QoS, AutoQoS VoIP, AutoQoS Enterprise
3. Measure / Adjust – Netflow, NBAR, IP SLA, Syslog
4. Deploy Apps – Netflow, NBAR

• https://en.wikipedia.org/wiki/NetFlow
• Cisco NBAR
• WhitePaper AutoQoS
• Cisco IP SLA

Syslogging

• Key practices:
  • Set the right date / time.
  • Use the same IOS version ( different messages, severity ).
  • Out of Band management ( security , performance ).
  • Centralized logging server.

Netflow

• https://en.wikipedia.org/wiki/NetFlow
• Esed for Traffic accounting
• Heavily used by:
  • Service Providers
    • Network Planning
    • Accounting and Billing
    • Security
    • Traffic Engineering
  • Enterprise Customers
    • Internet Conenction Monitoring
    • User / Application Monitoring
    • Security
• NetFlow tracks Flows ( Sessions )
  • IP Source Address
  • IP Destination Address
  • Source Port Number
  • Destination Port Number
  • Protocol type ( udp / tcp / etc )
  • Input Interface

NBAR (Network Based Application Recognition) / AutoQoS

• • Cisco NBAR
  • WhitePaper AutoQoS
  • Identifies Applications in traffic flows
  • Inspects layer 2-4 , layer 7 data for supported applications ( around 90 supported )
  • Expandable through IOS Upgrades and PDLMs (Packet Description Language Module)
  • Integrates with QoS mechanics
  • Integrats with SNMP mechanics
• Starting with NBAR
  • sh ip nbar protocol-discovery stats bit-rate top-n 10
  • Onboard IOS tools allow for top x reporting
  • Gobs of monitoring tools use this data (MRTG, Cacti, Zabbix)
  • Integrates into class-map ( QoS ) and AutoQoS Mechanics

AutoQoS

• Cisco AutoQoS
• Comes in two flavours:
  • AutoQoS for VoIP ( Pre-defined policy-map templates)
    • Creates about 40 lines of config
  • AutoQoS for Enterprise ( application sniffing with NBAR )
    • Uses NBAR to identify the key applications
• Trusted Mode ( Believes existing DSCP )
• Untrusted Mode ( Leverages NBAR Discovery )

IP SLA

• • Cisco IP SLA
  • Technically:
    • A contract with a service level guarantee
    • In Cisco: A method of measuring service level by sending test traffic.
  • Able to Measure:
    • Network Delay
    • Packet loss
    • Jitter
    • Voice Quality
  • SNMP Reporting also an option.