Speaker Introduction to VLAN IGMP Spanning Tree Protocol

Speaker：龔哲幀 指導教授：柯開維教授 Introduction to VLAN, IGMP, Spanning Tree Protocol

Outline �VLAN(Virtual LAN) What are VLANs ? Why need the VLAN ? VLAN Configurations VTP (VLAN Trunking Protocol) �IGMP (Internet Group Management Protocol) IGMP V 1/V 2/V 3 IGMP Snooping �Spanning Tree

What are VLANs ? Why need the VLAN ? heavily burdened ü Segmentation ü Scalability & Flexibility ü Security

VLAN Configurations � Port-based VLAN � MAC-based VLAN � IP subnet-based VLAN � Protocol-based VLAN � Rule-based VLAN

Port-based VLAN p Easy to setup configuration, but inflexible

MAC-based VLAN p Provide good security since spoofing a MAC address is not easy

IP subnet-based VLAN

Protocol-based VLAN

Rule-based VLAN

VTP (VLAN Trunking Protocol) �VTP Pruning p 在Switch中，我們還可以啟動VTP Pruning功能， 以刪除不必要的flooded traffic 的資訊通過其它的 Switch，以節省頻寬，增加整體網路效能。

IGMP (Internet Group Management Protocol) �主要是用來定義如何在Layer 3建立multicast group，這個protocol不是用來傳送資料用 的，專門用來建立與管理multicast group 。 p D class (224. 0. 0. 0 ~ 239. 255) 是用來做multicast group

IGMP (Internet Group Management Protocol) �IGMPv 1: Hosts can join multicast groups. There were no leave messages. Routers were using a time -out based mechanism to discover the groups that are of no interest to the members.

IGMP (Internet Group Management Protocol) �IGMPv 2: Leave messages were added to the protocol. Allow group membership termination to be quickly reported to the routing protocol, which is important for high-bandwidth multicast groups and/or subnets with highly volatile group membership.

IGMP (Internet Group Management Protocol) �IGMPv 3 Major revision of the protocol. It allows hosts to specify the list of hosts from which they want to receive traffic from. Traffic from other hosts is blocked inside the network. It also allows hosts to block inside the network packets that come from sources that sent unwanted traffic.

IGMP Snooping �IGMP snooping（Internet Group Management Protocol snooping）是運行在 layer 2 Ethernet Switches上的群播約束機制， 用於管理和控制群播組。

IGMP Snooping �IP multicasting without IGMP snooping B C A D

IGMP Snooping �IP multicasting with IGMP snooping B C A D

Spanning Tree �Without STP Broadcast Storm

Spanning Tree �With STP

Spanning Tree � STP運作原理有下列要素： 每個網路上都有一個Root Bridge 每個non-Root Bridge 有一個Root Port 每個區段上都有一個Designated Port Non-designated Port 是無用的，通常就是被Blocking的 Port。 � Root Bridge是由最低的Bridge ID所得。 � Bridge ID是由Priority 加上MAC address所組成。 � Root Port是由到達Root Bridge最低Path Cost (路徑成本)的 Port所取得。

Spanning Tree

Reference � Cisco ROUTER入門之理論、實務與認證，蕭文龍、林 奇南，2006，碁華。 � 區域網路交換器技術發展，田慶明， 研院交大網路測 試中心。 � http: //speed. cis. nctu. edu. tw/~ydlin/course/cn/exp/ Exp_NBL/stp_manual. pdf � http: //guiderworld. blogspot. com/2009/03/layer-2 switch. html � http: //www. cs. nthu. edu. tw/~nfhuang/chap 16. htm � http: //blog. xuite. net/jackytseng 7028/Wiki. Life/2652 3148 � http: //en. wikipedia. org/wiki/IGMP_snooping � 柯開維教授上課投影片

Q&A Thanks for your attention!