Expl sw chapter_03_vla_ns_part_ii

CCNA3-1 Chapter 3-2

Virtual Local Area NetworksVirtual Local Area Networks

VLAN TrunkingVLAN Trunking

CCNA3-2 Chapter 3-2


• Concept trunking pertama kali digunakan di perusahaan telephone.

• Multiple calls dipindahkan antara customers dan central offices atau antar offices, dengan 1 physical connection.

CCNA3-3 Chapter 3-2


• Dengan prinsip yang sama, trunking diterapkan pada data Dengan prinsip yang sama, trunking diterapkan pada data communications untuk memaksimalkan pemakaian jalur communication communications untuk memaksimalkan pemakaian jalur communication yang lebih baik secara bersama-sama.yang lebih baik secara bersama-sama.

• Keuntungan lainnya adalah penghematan cost, karena menggunakan Keuntungan lainnya adalah penghematan cost, karena menggunakan jalur yang sama untuk komunikasi data dan voice.jalur yang sama untuk komunikasi data dan voice.

24 Channel T1 Line with Data and Voice

CCNA3-4 Chapter 3-2


• Dengan prinsip yang sama juga, trunking diterapkan pada network yang Dengan prinsip yang sama juga, trunking diterapkan pada network yang menggunakan teknologi switching.menggunakan teknologi switching.

• TrunkTrunk merupakan merupakan physical dan logicalphysical dan logical connections antara 2 switches connections antara 2 switches yang melewatkan traffik network dari beberapan vlan network. yang melewatkan traffik network dari beberapan vlan network.

No trunkNo trunkNo trunkNo trunk

TrunkTrunkTrunkTrunk

CCNA3-5 Chapter 3-2


• Perlu diketahui link trunkPerlu diketahui link trunkbukan milik bukan milik VLAN id VLAN id tertentu.tertentu.

• Tanggungjawab dariTanggungjawab darilink trunk adalah sebagailink trunk adalah sebagaiconduit/saluranconduit/saluran untuk untuk VLANs.VLANs.• Diantara Diantara switchesswitches dan dan

routersrouters, atau, atau• Diantara Diantara switchesswitches

dan dan switchesswitches. .

CCNA3-6 Chapter 3-2

VLAN TrunksVLAN Trunks

• What problem does it solve?What problem does it solve?

Network 172.17.10.0/24Network 172.17.10.0/24Network 172.17.10.0/24Network 172.17.10.0/24

Network 172.17.20.0/24Network 172.17.20.0/24Network 172.17.20.0/24Network 172.17.20.0/24

Network 172.17.99.0/24Network 172.17.99.0/24Network 172.17.99.0/24Network 172.17.99.0/24Network 172.17.30.0/24Network 172.17.30.0/24Network 172.17.30.0/24Network 172.17.30.0/24

CCNA3-7 Chapter 3-2

IEEE 802.1Q Frame TaggingIEEE 802.1Q Frame Tagging

• Harus kita ingat bahwa switches adalah device Layer 2.• Hanya menggunakan Ethernet frame header information untuk

berkomunikasi.• Frame header tidak mengandung information mengenai VLAN

membership.• Untuk itu VLAN membership (i.e. VLAN ID or VLAN Number) harus di

identifikasikan untuk setiap frame yang di lewatkan melalui trunk.• Process ini dinamakan: “802.1Q VLAN Tagging”.

CCNA3-8 Chapter 3-2

IEEE 802.1Q Frame TaggingIEEE 802.1Q Frame Tagginghttp://www.cisco.com/en/US/tech/tk389/tk689/technologies_tech_note09186a0080094665.shtml

6 6 2 1500 4

Destination Address

Source Address

Type /Length

DataMax of 1500 Bytes

FCS

6 6 2 2 2 1500 4

Destination Address

Source Address

802.1Q TagType/Length

DataMax of 1500 Bytes

NewFCS8100 Tag

Length 1518 BytesLength 1518 BytesLength 1518 BytesLength 1518 Bytes


CCNA3-9 Chapter 3-2

IEEE 802.1Q Frame TaggingIEEE 802.1Q Frame Tagginghttp://en.wikipedia.org/wiki/IEEE_802.1Q

http://en.wikipedia.org/wiki/MAC_address#Bit-reversed_notation


CCNA3-10 Chapter 3-2

Native VLANsNative VLANs

• Configure identifikasi trunk menggunakan Configure identifikasi trunk menggunakan default vlandefault vlan or or native vlannative vlan yaitu yaitu VLAN 1VLAN 1..

• Configure identifikasi trunk menggunakan Configure identifikasi trunk menggunakan native vlannative vlan ke ke VLAN 99VLAN 99..


Native VLANsNative VLANs

• Verify the configuration.Verify the configuration.• VLAN 50 is a voice VLAN.VLAN 50 is a voice VLAN.


Trunking OperationTrunking Operation

PC1 and PC3PC1 and PC3send a broadcast.send a broadcast.

PC1 and PC3PC1 and PC3send a broadcast.send a broadcast.

10101010

20202020

30303030

10101010

20202020

30303030

S2 receives the frames and S2 receives the frames and ‘tags’ them with the VLAN ID.‘tags’ them with the VLAN ID.S2 receives the frames and S2 receives the frames and

‘tags’ them with the VLAN ID.‘tags’ them with the VLAN ID.

The tagged frames are sent The tagged frames are sent across the trunk links between across the trunk links between

S2 and S1 and S1 and S3.S2 and S1 and S1 and S3.

The tagged frames are sent The tagged frames are sent across the trunk links between across the trunk links between

S2 and S1 and S1 and S3.S2 and S1 and S1 and S3.

S3 strips the tags and S3 strips the tags and forwards to the destination.forwards to the destination.

S3 strips the tags and S3 strips the tags and forwards to the destination.forwards to the destination.


Trunking ModesTrunking Modes

• A Cisco switch can be configured to supportA Cisco switch can be configured to support two types two types of of trunk ports:trunk ports:• IEEE 802.1QIEEE 802.1Q• ISL ISL (Inter-Switch Link)(Inter-Switch Link)

• Supported by all catalyst switches except 29XX seriesSupported by all catalyst switches except 29XX series

• Today only 802.1Q is used.Today only 802.1Q is used.• Legacy networks may still use ISL.Legacy networks may still use ISL.



• IEEE 802.1Q trunk port is:• Mendukung tagged dan untagged traffic secara simultan.• Dilakukan oleh default PVID. (Port VLAN ID)• Untagged traffic:

• Di assosiasikan dengan port default PVID.• Null atau untagged VLAN ID traffic merupakan milik

default PVID.• VLAN ID sama dengan port default PVID dikirim

keluar sebagai untagged.• Tagged traffic:

• Semua traffic lainnya dikirim dengan VLAN tag.



• ISL (Inter-Switch Link):• Semua paket yang diterima akan di-encapsulated dengan

ISL header.• Semua transmitted packets dikirim dengan ISL header.• Untagged frames yang dikirim dari ISL trunk port akan di

dropped.• No longer recommended or supported.

• 30 bytes of overhead for each frame…..



• Dynamic Trunking Protocol (DTP):• Cisco proprietary protocol.

• Negosiasi both status & trunk encapsulation dari trunk ports

• Switches dari vendors lain tidak support DTP.• Secara auto akan enable pada port switch ketika mode

trunking tertentu dikonfigurasi pada port switch tersebut.• DTP manages trunk negotiation only if the port on the

other switch is configured in a trunk mode that supports DTP.

• DTP supports both ISL and 802.1Q trunks. • Some Cisco switches and routers (older versions) do not

support DTP.


Trunking ModesTrunking Modeshttp://www.cisco.com/en/US/docs/switches/lan/catalyst6500/ios/12.2SX/configuration/guide/layer2.html

Mode Dynamic Trunking Protocol (DTP):Mode Dynamic Trunking Protocol (DTP):•Dynamic Auto: (switchport mode dynamic auto)

• The switch port periodically sends DTP frames to the remote port. Dan mengiklankan ke remote port bahwa dia bisa berubah ke mode trunk, tetapi tidak meminta remote port untuk berubah ke trunk state. (enable on default)

•On (default/standart): (switchport mode trunk)

• Periodically sends DTP advertisements to the remote port and remote port dynamically changing to a trunking state.

•Dynamic Desirable: (switchport mode dynamic desirable)

• DTP frames are sent periodically to the remote port. It advertises to the remote switch port that it is able to trunk and asks the remote switch port to go to the trunking state.



• Dynamic Trunking Protocol (DTP):Dynamic Trunking Protocol (DTP):• Turn off DTP: Turn off DTP: ((switchport nonegogiateswitchport nonegogiate))

• The local port does not send out DTP frames to the The local port does not send out DTP frames to the remote port.remote port.

• Mengakibatkan Local port akan berada pada kondisi Mengakibatkan Local port akan berada pada kondisi Unconditional TrunkingUnconditional Trunking state. state.

• Use this feature when you need to configure a trunk Use this feature when you need to configure a trunk with a switch from another switch vendorwith a switch from another switch vendor..


Virtual Local Area NetworksVirtual Local Area Networks

Configure VLANs and TrunksConfigure VLANs and Trunks““Let's look at the lab”Let's look at the lab”


Configure VLANs and TrunksConfigure VLANs and Trunks

• Overview:Overview:

1.1. Create the VLANs.Create the VLANs.

2.2. Assign switch ports to VLANs statically.Assign switch ports to VLANs statically.

3.3. Verify VLAN configuration.Verify VLAN configuration.

4.4. Enable trunking on the inter-switch connections.Enable trunking on the inter-switch connections.

5.5. Verify trunk configuration.Verify trunk configuration.


Configure a VLANConfigure a VLAN

• Command Syntax:Command Syntax:

S1#S1#configure terminalconfigure terminal

S1(config)#S1(config)#vlanvlan vlan idvlan id

S1(config-vlan)#S1(config-vlan)#namename vlan namevlan name

S1(config-vlan)#S1(config-vlan)#endend



Configure a VLANConfigure a VLANConfigure a VLANConfigure a VLAN



Assign switch ports to a VLANAssign switch ports to a VLANAssign switch ports to a VLANAssign switch ports to a VLAN



Verify VLAN configurationVerify VLAN configurationVerify VLAN configurationVerify VLAN configuration


Managing VLANsManaging VLANs

OtherOther show vlanshow vlan command options command optionsOtherOther show vlanshow vlan command options command options



show interfacesshow interfaces command commandshow interfacesshow interfaces command command



Manage VLAN MembershipsManage VLAN MembershipsManage VLAN MembershipsManage VLAN Memberships

Remove port VLAN membership.Remove port VLAN membership.Remove port VLAN membership.Remove port VLAN membership.


• If you remove the VLAN If you remove the VLAN before removing the port before removing the port membership membership assignments, the ports assignments, the ports become unusablebecome unusable until until you issue theyou issue the no switchport access vlan no switchport access vlan command. command.


Manage VLAN MembershipsManage VLAN MembershipsManage VLAN MembershipsManage VLAN Memberships

Remove a VLANRemove a VLANRemove a VLANRemove a VLAN

Remove port VLAN membership.Remove port VLAN membership.Remove port VLAN membership.Remove port VLAN membership.



• Restoring to Factory Defaults:Restoring to Factory Defaults:• To remove all VLAN configuration:To remove all VLAN configuration: VLAN VLAN

configuration configuration stored here.stored here.

VLAN VLAN configuration configuration stored here.stored here.


Configure a TrunkConfigure a Trunk

• Command Syntax:Command Syntax:

S1#S1#configure terminalconfigure terminal

S1(config)#S1(config)#interface interface interface-idinterface-id

S1(config-if)#S1(config-if)#switchport mode trunkswitchport mode trunkS1(config-if)#S1(config-if)#switchport trunk native vlan switchport trunk native vlan

vlan-idvlan-id S1(config-if)#S1(config-if)#switchport trunk allowed vlan switchport trunk allowed vlan

add add vlan-vlan-listlist

S1(config-vlan)#S1(config-vlan)#endend


Configure a TrunkConfigure a Trunk


Configure a Trunk (p149)Configure a Trunk (p149)

The native VLAN must The native VLAN must match on match on bothboth switches. switches.The native VLAN must The native VLAN must

match on match on bothboth switches. switches.


Verify Trunk ConfigurationVerify Trunk Configuration


Managing a Trunk ConfigurationManaging a Trunk Configuration


Managing a Trunk ConfigurationManaging a Trunk Configuration

• Pruning:Pruning:• The process of specifying the traffic that will be allowed to The process of specifying the traffic that will be allowed to

traverse the trunk link.traverse the trunk link.• Use the command:Use the command:

switchport trunk allowed vlan addswitchport trunk allowed vlan add vlan-listvlan-list

• The The vlan-listvlan-list is a list of the VLAN IDs, separated by is a list of the VLAN IDs, separated by commas, that will be allowed to use the trunk link.commas, that will be allowed to use the trunk link.

• The lists must match on both switches.The lists must match on both switches.


Common Problems with TrunksCommon Problems with Trunks

• Native VLAN mismatches:Native VLAN mismatches:• Trunk ports are configured with different native VLANs.Trunk ports are configured with different native VLANs.

• Trunk Mode mismatches:Trunk Mode mismatches:• One trunk port is configured with trunk mode One trunk port is configured with trunk mode offoff and the and the

other with trunk mode other with trunk mode onon..• VLANs and IP Subnets:VLANs and IP Subnets:

• End user devices configured with incorrect IP addresses End user devices configured with incorrect IP addresses will not have network connectivity. Each VLAN is a will not have network connectivity. Each VLAN is a logically separate IP subnetwork. Devices within the logically separate IP subnetwork. Devices within the VLAN must be configured with the correct IP settings.VLAN must be configured with the correct IP settings.

• Allowed VLANs on trunks:Allowed VLANs on trunks:• The list of allowed VLANs on a trunk does not match on The list of allowed VLANs on a trunk does not match on

both ends of the trunk.both ends of the trunk.

Technology

Expl sw chapter_03_vla_ns_part_ii