Rstp Mstp Marvin

Embed Size (px)

DESCRIPTION

RSTP

Citation preview

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    RSTP and MSTP

    Marvin Rambhadjan

    UvA

    February 25, 2010

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Overview

    Rapid Spanning Tree Protocol

    Per VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Rapid Spanning Tree Protocol

    IEEE 802.1w 1998

    Underlying protocol MSTP

    I Similarities with STPI Calculate the same spanning tree topology with the same

    configuration

    I Differences with STPI Faster conversion timesI Different port states and new port rolesI Different definition topology changeI BPDUs used for Hello mechamism

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    RSTP Port States and Roles

    I Port States

    Forwarding MAC LearningForwarding traffic

    Learning MAC LearningNo forwarding traffic

    Disabled No MAC learningNo forwarding traffic

    I Port Roles

    Root Port Port to higher segments (to the Root Bridge)Designated Port Port to lower segmentsAlternate Port Backup Root PortBackup Port Backup Designated PortDisabled Port Not participating in RSTP

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Port Roles

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Definition Topology Change

    I STPI A Forwarding or Listening state port that transits to Blocking (lost

    connection)I A port that transits in Forwarding state, while the switch already has

    a Designated port (new connection)

    I RSTPI Non-Edge port that transits in Forwarding (new connection)

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Rapid transit to Forwarding

    I Edge PortsI End stationsI Not part of spanning tree process

    I Point to PointI Connection between switchesI Proposal and Agreement mechanism

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Proposal and Agreement Mechanism

    If a designated port wants to transits into a non-discarding state, theupstream switch will do the following in order to agree with thedownstream switch.

    1. Upstream Bridge sends proposal on Designated Port

    2. Downstream Bridge receives proposalI If it agrees on port role, it starts synchronization.I If it not agree on the proposal, it will send is own proposal

    3. Downstream Bridge blocks all non-edge Designated Ports and sendAgreement to upstream bridge

    4. Synchronization is needed to make sure there are no loops in thetopology when when the upstream bridge unblocks its DesignatedPort

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Proposal and Agreement

    www.cisco.com

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Proposal and Agreement

    www.cisco.com

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Proposal Agreement

    www.cisco.com

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Proposal Agreement

    www.cisco.com

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Proposal Agreement

    www.cisco.com

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Topology Changes

    TC DetectionI Start TC While timer (2x Hello-Time) on all Non-Edge designated

    and root portsI Flush all MAC addresses on these portsI Sends BPDUs with TC bit set, while TC While timer has not expired

    TC PropagationI Flush all MAC addresses on all ports except receiving portI Start TC While timer and sends BPDUs with TC bit set on all

    Designated and Root portsI TCN not longer used

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Per VLAN Spanning Tree

    I Many different variantsI ProprietaryI For both STP and RSTP

    I Load BalancingI Create independent spanning tree instances

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Single Spanning Tree

    I Not all connections are used

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Per VLAN Spanning Tree

    I 10 Root BridgesI 10 BPDUsI 10 Spanning Tree calculations

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Multiple Spanning Tree Protocol

    IEEE 802.1s 2003

    Built on RSTP

    I MSTP vs (R)STPI Use all links

    I MSTP vs PVSTI Minimize overhead

    I Introduction RegionsI Two-Level HierarchyI Multiple independent Spanning Tree Instances

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    MSTP Terminology

    I CIST Common Internal Spanning TreeI Topology of all switches in all regions

    I CST Common Spanning TreeI Topology of all pseudo bridges

    I IST (MSTI0) Internal Spanning TreeI Spanning Tree within a regionI Can communicate with other regionsI Root Bridge election first based on External Path Cost

    I MSTIn Multiple Spanning Tree Instance nI Spanning Tree within a regionI Cannot communicate with other regions

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    MSTP parameters

    I MSTP Region parametersI VLAN-to-instance mappingI Configuration NameI Configuration Revision

    I Root Priority per MSTII Path cost per MSTII Port Priority per MSTI

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Example IST

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Example MSTIs

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    MSTP Multi Region

    I Every region becomes a pseudo-bridgeI Topology of pseudo-bridges is called CSTI CST has no idea of internal MSTP regions

    Hierarchy

    I First LayerI Common Internal Spanning Tree (CIST)I Collection of Internal Spanning Tree (IST)

    I Second LayerI Internal Spanning Tree (IST)I Multiple Spanning Tree Instance(s) (MSTI)

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Example MSTP Multi Region Topology

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Example MSTP Multi Region Root Ports

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Example MSTP Multi Region Designated Ports

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Example MSTP Multi Region CIST

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Example MSTP Pseudo-Bridges CST

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Example MSTP Within a Region

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Example MSTP Within a Region

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Bridge Protocol Data Unit

    Octet BPDU Content

    1 - 2 Protocol Identifier Spanning Tree Protocol 0x0000

    3 Protocol Version Identifier Multiple Spanning Tree 3

    4 BPDU Type Rapid/Multiple Spanning Tree (0x02)

    5 CIST Flags

    6 - 13 CIST Root Identifier

    14 - 17 CIST External Path Cost

    18 - 25 CIST Regional Root Iden-tifier

    26 - 27 CIST Port Identifier

    28 - 29 Message Age

    30 - 31 Max Age

    32 - 33 Hello Time

    34 - 35 Forward Delay

    36 Version 1 Length 0

    37 - 38 Version 3 Length Number of octets in MSTP extension64 octets MSTP Extension & 16 octetsper MSTI

    39 - 102 MSTP ExtensionMarvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Bridge Protocol Data Unit

    Octet MSTP Extension Content

    39 MST Config ID Format Selector 0

    40 -71 MST Config Name

    72 - 73 MST Revision

    74 - 89 MST Config Digest

    90 - 93 CIST Internal Path Cost

    94 - 101 CIST Bridge Identifier

    102 CIST Remaining Hops

    MSTIDn MSTI Instances

    Octet MSTID instance number Content

    1 MSTI Flags

    2 - 9 MSTI Regional Root Identifier

    10 - 13 MSTI Internal Root Path Cost

    14 MSTI Bridge Priority

    15 MSTI Port Priority

    16 MSTI Remaining Hops

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Flags

    Bits Description1 Topology Change Acknowledgement1 Agreement1 Forwarding1 Learning2 Port Role1 Proposal1 Topology Change

    Marvin Rambhadjan RSTP and MSTP

  • Rapid Spanning Tree ProtocolPer VLAN Spanning Tree

    Multiple Spanning Tree Protocol

    Questions?

    Marvin Rambhadjan RSTP and MSTP

    Rapid Spanning Tree ProtocolPer VLAN Spanning TreeMultiple Spanning Tree Protocol