1. STP PVST EtherChannel HSRP

·

2 min read

STP (Spanning Tree Protocol)

  • Blocking specific ports to avoid broadcast loops.

  • Set root switch, determine root ports based on the root switch, and designate designated ports and undesignated ports (criteria: switch priority, cost to the root switch, port number). Block the undesignated ports.

  • Prevents resource exhaustion caused by broadcast loops.


PVST (Per-VLAN Spanning Tree)

  • Set the root switch for each VLAN.

  • The downside of STP is the wasted ports due to blocking. PVST addresses this downside by allowing each VLAN to have its own root switch, maximizing the use of ports.

  • Traffic load balancing on each VLAN.

  • I believe this solution is effective when VLANs are configured.


EtherChannel

  • Combines multiple physical links into one logical link to increase bandwidth.

  • Improves both bandwidth and availability.

  • Protocols:

    • LACP (Link Aggregation Control Protocol): Standard protocol.

      • Modes: Active (requests link aggregation) / Passive (responds to link aggregation requests).
    • PAgP (Port Aggregation Protocol): Cisco-specific protocol.

      • Modes: Desirable (actively requests aggregation) / Auto (responds to aggregation requests).

HSRP (Hot Standby Router Protocol)

  • Cisco's version of FHRP (First Hop Redundancy Protocol).

  • What is FHRP?

    • Provides redundancy for routers acting as gateways.

    • There is a logical gateway represented by two routers.

  • One router is active, and the other is standby.

  • Preempt Option: By default, this protocol doesn't automatically switch back to the original active router when it comes back online. However, if the Preempt option is enabled, the original active router will automatically reclaim the active role after recovery.

  • If the VLAN is configured, this protocol can also balance loads across VLANs, similar to PVST but on the router level.