Routers and Switches Review

Review of IOS for Routers and Switch

  • Subinterface – Commands that configure multiple virtual interfaces on a single physical interface.
  • Router – Commands that configure an IP routing protocol.

Medium Sized Switched Network Construction

  • VLAN is a logical broadcast domain that can span multiple physical segments.
  • Trunk ports carry ALL VLAN traffic
  • VLAN = Broadcast domain = subnet
  • A native VLAN carries all UNTAGGED frames.
  • VTP domain is one or several switches sharing the same VTP environment.

VTP Modes:

Server: VTP Messages are propagated over all trunk links.

Transparent: Changes affect the local switch only and does not propagate.  Forwards advertisements but does not sync with other devices..

Clients: Advertisements are forwarded and synchronise  with server switches.

VTP advertisements are flooded throughout the management domain, every 5 minutes or whenever a change is made.


Higher revision number -> more current information

To change the VTP config number:

  • Change the VTP domain name or change it back
  • Change to VTP transparent mode then back

VTP Pruning: Restricts the flow of traffic only to ports within the VLAN’s that the traffic is destined for -> Server mode only.

A trunk port cannot be a secure port.


  • 1 Native VLAN
  • 2 – 1001 Normal VLAN Range
  • 1002 – 1005 Reserved for Token Ring and FDDI

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