Posts tagged interface

ONT Notes – AutoQoS

Feb 10th

Posted by Aaron Conaway in ccnp

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  • AutoQoS benefits
    • Automates QoS for most deployments
    • Protects business-critical apps to maximize availability
    • Simplifies QoS deployments
    • Reduces configuration errors
    • Cheaper, faster, and simpler deployments
    • Follows DiffServ
    • Allows complete control over QoS configs
    • Allows modification of auto-generated configs
  • AutoQoS phases of evolution
    • AutoQoS VOIP – Early version that configures the basics without discovery
    • AutoQoS for Enterprise – Second version that only runs on routers and uses two-step process
      • Autodiscovery using NBAR
      • Generation of class maps
  • AutoQoS key elements
    • Application classification
    • Policy generation
    • Configuration
    • Monitoring and reporting
    • Consistency
  • Interfaces that you can configure AutoQoS on
    • Serial ifs with PPP and HDLC
    • FR point-to-point subifs (NOT multipoint)
    • ATM point-to-point subifs
    • FR-to-ATM links
  • Prerequsites
    • No Qos policy already configured on if
    • CEF enabled on if
    • Correct bandwidth configured on if
    • IP address on low-speed if
  • Configuring AutoQoS Enterprise on a router (NOT a switch)
    • auto qos discovery – begins discovery process
    • auto qos – generates and applies MQC-based policies
  • Configuring AutoQoS VOIP
    • auto qos voip [ trust | cisco-phone ]
  • Verifying AutoQoS on router
    • show auto discovery qos – get autodiscovery results
    • show auto qos – examine configuration generated
      • Number of classes
      • Classification options
      • Marking options
      • Queuing mechanisms
      • Other QoS mechanisms
      • If, subif, PVC where policy is applied
    • show policy-map interface – look at if stats
  • Verify AutoQoS VOIP
    • show auto qos
    • show policy-map interface
    • show mls qos maps – shows CoS to DSCP mappings
  • Possible issues with AutoQoS
    • Too many traffic classes – manually consolidate some
    • Configuration doesn’t change – rerun AutoQoS
    • Configuration may not fit your situation – fine-tune it by hand
  • Fine-tuning AutoQoS
    • Use QPM
    • CLI
    • copy policy into editor, change, reapply
  • AutoQoS can match on characteristics besides ACLs and NBAR
    • match input interface
    • match cos
    • match ip precedence
    • match ip dscp
    • match ip rtp
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ONT Notes – Pre-classify and End-to-end QoS

Feb 3rd

Posted by Aaron Conaway in ccnp

2 comments

  • VPNs (Didn’t ISCW cover this?)
    • Provide
      • Confidentiality
      • Integrity
      • Authentication
    • Types
      • Remote-access
        • Client-initiated
        • NAS-initiated
      • Site-to-site
        • LAN-to-LAN
        • Extranet
  • L3 Tunneling protocols
    • GRE
    • IPSec
  • Pre-classify allows traffic to be classified before being sent across a tunnel or crypto-ed.
    • qos pre-classify
    • Provides a view into the original IP headers
    • To classify on pre-tunnel header, apply the policy to the tunnel interface WITHOUT pre-classify.
    • To classify on post-tunnel header, apply the policy to the physical interface WITHOUT pre-classify.
    • To classify on pre-tunnel header, apply the policy to the physical interface WITH pre-classify.
  • SLA – agreement with provider to guarantee QoS mechanisms across their network based on your markings.
    • Assures availability, loss, throughput, delay, and jitter.
  • End-to-end QoS
    • To be effective, each hop in the path must have QoS configured similarly.
    • Necessary in three locations
      • Campus – within the customer network
      • The edges – customer facing the provider, provider facing customer
      • On the provider network
  • QoS tasks
    • Campus access switches
      • Speed/duplex settings
      • Classification
      • Trust
      • Phone/access switch configs
      • Multiple queues on switch ports, including priority for VOIP
    • Campus distribution
      • L3 policing and marking
      • Multiple queues on switch ports, including priority for VOIP
      • WRED
    • WAN edge
      • SLA definitions
      • LLQ
      • LFI
      • WRED
      • Shaping
    • Provider cloud
      • Capacity planning
      • PHB
      • LLQ
      • WRED
  • Enterprise campus QoS implementation
    • Implement multiple queues to avoid congestion
    • Assign VOIP and video to highest priority queue
    • Esablish trust boundaries
    • Use policing to rate-limit excess traffic
    • Use hardware QoS when possible
  • Control Plane Policing (CoPP)
    • Applies QoS policy to traffic destined for the router
      • Routing protocols
      • Management protocols
    • Can be used to avoid DOS attacks
    • Applied to control-plane in global config
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