CCNP Exam Prep Tips and Must Knows

Things You’ll Need to Know about VLAN Deployment:

End to End VLANs

• Geographically dispersed users appear on the same subnet
• Same policy can be applied to same group of users
• All switches need to know all vlans
• Broadcast frames flood all switches
• Troubleshooting may be challenging

Local VLANs

• Design is scalable
• Troubleshooting is easier
• Traffic flow is predictable
• Redundant paths can be built easily
• More routing devices are required than in end to end model
• Users belong to the same broadcast domain when they are at the same location

Dynamic Trunking Protocol – DTP

Trunk Configuration Recommendations

• Configure vlans
• Configure trunk mode
• Disable trunk negotiation
• Manually remove unnecessary vlans from trunks
• Configure native vlan to unused vlan
• Disable Trunking on host ports
• Do not use VTP

Private VLANs

• A primary vlan is associated with secondary VLANs
• The secondary VLANs are either isolated VLANs  or community VLANs
• Hosts can communicate with promiscuous ports
• The hosts on community VLANs can also communicate within same community
• A promiscuous port communicates with all other ports
• Typically a promiscuous port connects to a Layer 3 switch that is configures as the default gateway for hosts

Private VLAN Configuration

• VTP must be configured as Transparent Mode
  • Sw(config)# vtp transparent
  • Create secondary VLANs
  • Sw(config)# vlan 201
  • Sw(config-vlan) # private-vlan community
• Create a primary vlan and associate the secondary vlans to it
  • Sw(config-vlan)# vlan 100
  • Sw(config-vlan)# private vlan primary
  • Sw(config-vlan)# private-vlan association 201
• Secondary VLANs will be configured as community ports or isolated ports
  • Sw(config-if)# switchport mode private-vlan host
  • Sw(config-if)# switchport private-vlan host-associate 100 201
• Configure switch ports as host or promiscuous
  • Sw(config-if)# switchport mode private-vlan promiscuous
  • Sw(config-if)# switchport private-vlan mapping 100 201

Make sure you can configure:

• VLANs
• Access ports
• Trunk ports      
• VTP
• Private VLANs
• Disable DTP

Know how to:

• Limit VLANs allowed in a trunk
• Configure Native VLAN
• Configure trunk encapsulation

Make sure you are familiar with output:

• Show interface status
• Show vtp status
• Show interface switchport
• Show interface trunk