Transcript CCNA 3 Module 3 Single
CCNA 3 v3.0 Module 9 VLAN Trunking Protocol
Cisco Networking Academy
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1
Objectives
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Trunking
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VTP
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Inter-VLAN routing
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Trunking Concepts Trunking links between switches allow for the sharing of VLAN information.
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Frame Filtering
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Frame Tagging
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VLANs and Trunking “Multi-colored link”
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Inter-Switch Link Protocol – Cisco
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Frame Tagging and Encapsulation Methods IEEE Cisco
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VLAN Trunking Protocol (VTP) The role of VTP is to maintain VLAN configuration consistency across a common network administration domain.
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VTP Mode Comparison A transparent switch will not modify its database when updates are received, nor will the switch send out an update indicating a change in its VLAN status. Except for forwarding VTP advertisements, VTP is disabled on a transparent switch.
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VTP Operation
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VTP Implementation
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There are two types of VTP advertisements: 1. Requests from clients that want information at bootup 2. Responses from servers There are three types of VTP messages: 1. Advertisement requests 2. Summary advertisements 3. Subset advertisements
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VTP and Trunk Links
• VTP messages are encapsulated in either ISL or IEEE 802.1Q protocol frames, and passed across trunk links to other devices.
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VTP Basic Configuration Steps 1.
2.
3.
4.
Determine the version number Choose the domain
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Choose the VTP mode Server or Client or Transparent Default is Server Password protect the domain
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VTP Server vs. VTP Client
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VLANs can only be created or deleted on a VTP Server switch.
VTP Client switches cannot create or delete VLANs.
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However, VTP Clients can update VTP Servers if they have a higher revision number Transparent Switches can add and delete VLANs but this information is not passed to the other switches in the VTP Domain.
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Inter-VLAN Routing
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Inter-VLAN Issues and Solutions Two of the most common issues that arise in a multiple-VLAN environment are as follows: 1. The need for end-user devices to reach nonlocal hosts 2. The need for hosts on different VLANs to communicate
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“Router-on-a-Stick” I’m like a lollipop!
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Physical and Logical Interfaces IEEE 802.1q is more common
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Dividing Physical Interfaces into Subinterfaces
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Configuring Inter-VLAN Routing
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Two Options for Inter-VLAN Routing If "native" command is NOT supported: If "native" command IS supported: interface Fastethernet0/0 description Dot1q Trunk to Switch-2950 ip address 10.1.1.1 255.255.255.0
speed 100 !
full-duplex interface Fastethernet0/0.10
encapsulation dot1q 10 ip address 10.1.10.1 255.255.255.0
!
interface Fastethernet0/0.20
encapsulation dot1q 20 ip address 10.1.20.1 255.255.255.0
interface Fastethernet0/0 description Dot1q Trunk to Switch-2950 no ip address speed 100 !
full-duplex interface Fastethernet0/0.1
encapsulation dot1q 1 native ip address 10.1.1.1 255.255.255.0
!
interface Fastethernet0/0.10
encapsulation dot1q 10 ip address 10.1.10.1 255.255.255.0
!
interface Fastethernet0/0.20
encapsulation dot1q 20 ip address 10.1.20.1 255.255.255.0
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The ‘native’ Command
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The ‘ encapsulation dot1Q 1 native ’ was added in Cisco IOS version 12.1(3)T. command
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If you are using an earlier version of Cisco IOS, refer to the 802.1Q configuration on the previous slide.
The minimum IOS release required to support 802.1Q trunking on a 2620 or 2621 router is 12.0(1)T.
The native VLAN is used for untagged traffic when the port is in 802.1Q trunking mode.
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While configuring 802.1Q trunking, it is very important to keep in mind that the native VLAN must be configured the same on each side of the trunk link.
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