Mapa mental

Dugga 1

Tess - Inglês

Mind map about campus network switching: hierarchical models, VLAN technologies, trunking and STP

Mind map: campus network switching

Conteúdo do mapa

Dugga 1

Chapter 1
- Hierarchical models
  - Access layer
    - Provide access for workstations, servers, APs etc
    - High availability, convergence, security
  - Distribution layer
    - Service and control boundary between access and core layers
    - Uses switches to segment workgroups and isolate network problems
  - Core layer
    - BACKBONE!
    - Scalability and fast convergence
- Layer 4/7 switching
  - TCP/UDP
    - TCP SYN, FIN, RST
  - Application information
    - Content intelligence
- Multilayer switching
  - Layer 2 switching
    - Based on MAC
    - Frames are not modified
    - Catalyst 2960
      - Some layer 3 features
        QoS
        Network access control based on IP
  - Layer 3 switching
    - Can use routing protocols such as BGP, OSPF, EIGRP
    - Highly scalable designs
Chapter 2
- VLAN technologies in a campus network
  - End-to-end VLAN
    - Oldschool!
    - Every VLAN geographically exist everywhere
    - Same IP subnet
    - Switches typically operate in VTP server/client mode
  - Local VLAN
    - Exist between access and distrbution switches
    - Traffic only routed at the distribution and core levels to reach destinations on other networks
    - VTP transparent
    - Geopraphically local
  - Best practices
    - Local VLAN model
      - 1-3 VLANs per access module and limit those to a couple of access and distribution switches
    - Avoid VLAN1 as backhole
    - Use Dot1Q
    - Avoid VTP
- Trunking
  - ISL
    - Cisco
    - 26 byte junk
  - Dot1Q
    - IEEE
    - 4 byte tag
  - Native VLAN
    - Untagged traffic
    - Dot1Q should have the same native on both sides!
  - Dynamic trunking protocol
    - Access
      - Permanent non trunking
    - Trunk
      - Permanent trunking
      - Negotiates
    - Nonegotiate
      - Trunk if other end is
      - Use when connecting to device that does not support DTP
    - Dynamic desirable
      - Actively attempt to convert the link to trunk
        Trunk if neighbor is
    - Dynamic auto
      - Willing to convert to trunk
        If neighbor is dynamic desirable or trunk
- VTP
  - Client
    - Cannot create, change, delete
    - Forwards
    - Do not save
  - Server
    - Creates, modifies, deletes
    - Sends and forwards
    - Saves
  - Transparent
    - Create, deletes, modifies
    - Forwards but does not synch
    - Saves
  - Pruning
    - trunk connection is flooding traffic neccessarily
  - Versions
    - 1
    - 2
    - 3
  - Message types
    - Summary adverstisemnts
      - 5 minute increments
      - Current VTP domain name, revision number
    - Subset advertisements
      - Contians VLAN information
      - After summary
    - Advertisements requests
      - Switch has been reset
      - VTP domain name change
      - When recieved summary with higher revision number
  - Same password in all domain
- Private VLANs
  - Primary private
    - Secondary private
      - End devices
  - Community private
    - Talk to others in the same community and promiscuous
  - Isolated private
    - Talk to promiscuous
  - Port types
    - Isolated
    - Promiscuous
    - Community
  - Save IP
  - Port protected feature for those that does not support
- EtherChannel
  - Bundle links together
  - Protocols for messages
    - PAgP
      - Cisco
      - Auto, desirable, on, non-silent
    - LACP
      - IEEE 803.ad
      - Passive, active, on
  - Load balancing
    - Hash
      - Not same link if source MAC
Chapter 3
- RSTP (802.1w)
  - PVRST+ (Cisco)
    - Per VLAN
  - All VLANs
  - Port roles
    - Port states
      - Discarding
      - Learning
      - Forwarding
    - Root
      - On switches with link at root bridge
      - Forwards
    - Designated
      - On root bridge and non-root bridges
      - Forwards
    - Alternate
      - With an alternate path to root bridge
      - Disabled (not forwarding)
    - Backup
      - Additional port on designated switch with a redundant link to sement for which the switch is designated
    - Disabled
  - Link types
    - Shared (half-duplex)
    - P2p (full-duplex)
    - Edge port (portfast, workstations)
      - Allowed to transition directly to forwarding (skipping listening, learning)
      - If recieves BPDUs
        Looses edge port status and becomes part of spanning-tree
    - Root ports
      - Do not use the link parameter
    - Alternate, backup ports
      - Do not use the link parameter in most cases
    - Designated ports
      - Make the most use of link parameter
      - Rapid transition if link is p2p
- MSTP (802.1s)
  - VLAN list
  - To reduce total number of spanning-tree instances
  - Different regions
    - Instances
  - Enables load-balancing
- Recommended STP practices
  - Ethernet does not include TTL
  - Using layer 3 between distribution and core allows multipathing (up to 16)
- STP (802.1D)
  - Basics
    - Root bridge
      - Lowest priority or MAC
      - priority.macaddress
    - Port roles
      - Root port
        On switches with direct link to root bridge
        Forward data
      - Designated port
        On root and non-root bridges
        Forward data
      - Nondesignated port
        Not forwarding data (blocking)
      - Disabled port
        Shut down
    - Port states
      - Blocking
        Non-designated port
        20 sec
      - Listening
        Receiving and sending BPDUs
        15 sec
      - Learning
        Prepares to participate in forwarding
        15 sec
      - Forwarding
      - Disabled
  - PVSTP+ (Cisco)
    - Per VLAN
  - All VLANs
- Enhancements
  - Prevent unwanted devices from becoming root bridge
    - BPDU guard
      - On Portfast enabled ports
        Shut down port if recieve BPDU
    - BPDU filtering
      - Prevent sending BPDUs out access ports
      - If you enable with BPDU guard, BPDU filtering takes precendence
    - Root guard
      - Forces an interface to become desinganted
        Prevent surrounding switches from becoming a root switch
      - If it recieves superiour STP BPDUs, the port moves to a root-inconsistent state
        "listening"
        Does not forward traffic out that port
  - Loop guard
    - Port BPDU free
      - Forward traffic
      - An extra check before transitioning to the STP forwarding state
      - STP loop-inconsitent state
        If BPDU recieved
        The port transitions through STP states according to the recieved BPDU
        Recovery automatic
        "SPANTREE-2-LOOPGUARDBLOCK: port 3/2 restored in vlan 3."
        Does not pass traffic
    - Enable on all non-designated ports
  - UDLD
    - Unidirectional link
      - When traffic is transmitted between neighbors in one direction only
    - Useful on a fiber port to prevent network issues resulting in miswiring
    - When enabled
      - Periodically send UDLD packets to neighbors
        Expects packets to be echoed back before predetermined timer expires
        If timer expries
        Determined unidirectional
        Shut down
    - Modes
      - Normal
        Undetermined state if stops receiving BPDUs
      - Aggressive
        Tries to reestablish
    - Must be enabled on both sides
- Flex links
  - Alternative soution to STP
  - Based on defining an active/standby link pair on a common access switch
  - Configured on one layer 2 interface by assigning another as flex link or backup
    - When one of the links is up and forwarding, the other is in standby mode
      - Redy to begin forwarding traffic if the other link shuts down
- Troubleshoot
  - Duplex mismatch
  - Unidirectional link failure
  - Frame corruption
  - Resource errors
  - Portfast configuration error
  - Inappropriate STP diameter parameter tuning

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Descrição: Mapa Mental sobre Dugga 1, criado por Tess - em 21-09-2014.
Criado por: Tess -
Visualizações: 18
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