交换与路由基本知识PPT学习课件.ppt

Slide Title,Body Text,Second Level,Third Level,Fourth Level,Fifth Level,Slide Title,Body Text,Second Level,Third Level,Fourth Level,Fifth Level,Slide Title,Body Text,Second Level,Third Level,Fourth Level,Fifth Level,Slide Title,Body Text,Second Level,Third Level,Fourth Level,Fifth Level,Slide Title,Body Text,Second Level,Third Level,Fourth Level,Fifth Level,OSI,七层协议,OSI(Open System interconnection)开放系统互连参考模型,1、物理层 数据单位是位(BIT)，典型设备是集线器HUB。,2、链路层 数据单位是帧，实现对MAC地址的访问，典型设备是交换机Switch。,3、网络层 数据单位是包，使用的是IP地址，典型设备是路由器Router。,4、传输层 提供端到端的服务。可以实现流量控制、负载均衡。传输层信息包含,端口、控制字和校验和。传输层协议主要是TCP和UDP。,5、会话层 主要内容是通过会话进行身份验证、会话管理和确定通讯方式,6、表示层 主要是解释通讯数据的意义，如代码转换、格式变换等，使不同的终,端可以表示。还包括加密与解密、压缩与解压缩等。,7、应用层 应用层应该是直接面向用户的程序或服务，包括系统程序和用户程序，,例如www、FTP、DNS、POP3和SMTP等都是应用层服务。,数据包封装与解封装,数据在发送时是数据从应用层至物理层的一个打包的过程,接收时是数据从物理层至应用层的一个解包的过程,交换机,交换机是根据网桥的原理发展起来的，学习交换机先认识两个概念：,(1),冲突域：,冲突域是数据必然发送到的区域。,HUB,是无智能的信号驱动器，有入必出，整个由,HUB,组成的网络是一个冲突域。,交换机的一个接口下的网络是一个冲突域，所以交换机可以隔离冲突域。,(2),广播域：,广播数据时可以发送到的区域是一个广播域。,交换机和集线器对广播帧是透明的，所以用交换机和,HUB,组成的网络是一个广播域。,路由器的一个接口下的网络是一个广播域。所以路由器可以隔离广播域。,STP,交换网络中的环,以太网是总线或星型结构，不能构成环路，否则会产两个严重后果：,(1),产生广播风暴，造成网络堵塞。,(2),克隆帧会在各个口出现，造成地址学习,(,记录帧源地址,),混乱。,解决环路问题方案,:,(1),网络在设计时，人为的避免产生环路。,(2),使用生成树,STP(Spanning Tree Protocol),功能，将有环的网络剪成无环网络。,STP,被,IEEE802,规范为,802.1d,标准。,生成树协议术语,(1),网桥协议数据单元：,BPDU(Bridge Protocol Data Unit),BPDU,是生成树协议交换机间通讯的数据单元，用于确定角色。,(2),网桥号：,Bridge ID,交换机的标识号，它由优先级和,MAC,地址组成，优先级,16,位，,MAC,地址,48,位。,(3),根网桥：,Root bridge,根网桥定义为网桥号最小的交换机，根网桥所有的端口都不会阻塞。,(4),根端口：,Root port,非根网桥到根网桥累计路径花费最小的端口，负责本网桥与根网桥通讯的接口。,(5),指定网桥：,Designated bridge,网络中到根网桥累计路径花费最小交换机，负责收发本网段数据。,(6),指定端口：,Designated port,网络中到根网桥累计路径花费最小的交换机端口，根网桥每个端口都是指定端口。,(7),非指定端口：,NonDesignated port,余下的端口是非指定端口，它们不参与数据的转发，也就是被阻塞的端口。,(,根端口是从非根网桥选出，指定端口是网段中选出,),。,STP,生成树协议的状态：,生成树协议工作时，所有端口都要经过一个端口状态的建立过程。,生成树协议通过,BPDU,广播，确定各交换机及其端口的工作状态和角色，,交换机上的端口状态分别为：关闭、阻塞、侦听、学习和转发状态。,(1),关闭状态：,Disabled,不收发任何报文，当接口空连接或人为关闭时处于关闭状态。,(2),阻塞状态：,Blocking,在机器刚启动时，端口是阻塞状态,(20,秒,),，但接收,BPDU,信息。,(3),侦听状态：,listening,不接收用户数据,(15,秒,),，收发,BPDU,，确定网桥及接口角色。,(4),学习状态：,learning,不接收用户数据,(15,秒,),，收发,BPDU,，进行地址学习。,(5),转发状态：,Forwarding,开始收发用户数据，继续收发,BPDU,和地址学习,维护,STP,。,VLAN,VLAN(Virtual Lan),是虚拟逻辑网络,交换机通过,VLAN,设置，可以划分为多个逻辑网络，从而,隔离广播域。具有三层模块的交换机可以实现,VLAN,间的路由。,VLAN,(1)端口模式,交换机端口有两种模式，access和trunk。access口用于与计算机相连，而交换机之间的连接，应该是trunk。,交换机端口默认VLAN是VLAN1，工作在access模式。具有相同VLAN号的端口在同一个广播域中。,Trunk又称为干线，可以设置允许多个VLAN通过。,(2)VLAN中继协议：,VLAN中继协议有两种：,ISL(Inter-Switch Link)：ISL是Cisco专用的VLAN中继协议。,802.1q(dot1q)：802.1q是标准化的，应用较为普遍。,What Is an End-to-End VLAN?,Users are grouped into VLANs independent of physical location.,If users are moved within the campus,their VLAN membership remains the same.,VLAN Configuration Modes,Global Mode,Switch#,configure terminal,Switch(config)#,vlan 3,Switch(config-vlan)#,name Vlan3,Switch(config-vlan)#,exit,Switch(config)#,end,VLAN Configuration Modes,Database Mode,Switch#,vlan database,Switch(vlan)#,vlan 3,VLAN 3 added:,Name:VLAN0003,Switch(vlan)#,exit,APPLY completed.,Exiting.,VLAN Access Ports,The access switch port associated with a single data VLAN,VLAN Implementation Commands,Configuring VLANs,vlan 101,switchport mode access,switchport access vlan,101,Verifying VLANs,show interfaces,show,vlan,Configuring an Access VLAN,Switch(config)#vlan,vlan_id,Create a VLAN.,Switch(config-vlan)#name,vlan_name,Provide a VLAN name.,Switch(config-if)#switchport mode access,Place the switch port into access mode.,Switch(config-if)#,switchport access vlan,vlan_id,Associate the access switch port with a VLAN.,Verifying the Access VLAN Configuration,Switch#,show vlan,VLAN Name Status Ports,-,1 default active Fa0/1,Fa0/2,Fa0/3,Fa0/4,Fa0/5,Fa0/7,Fa0/9,11 asw11_data active,12 asw12_data active,95 VLAN0095 active Fa0/8,99 Trunk_Native active,100 Internal_Access active,111 voice-for-group-11 active,112 voice-for-group-12 active,1002 fddi-default act/unsup,1003 token-ring-default act/unsup,1004 fddinet-default act/unsup,1005 trnet-default act/unsup,VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1-,1 enet 100001 1500 -0,enet 100011 1500 -0,.,.,.,Defining VLANs,Implementing Trunks,Maintaining Specific VLAN Identification,Specifically developed for multi-VLAN interswitch communications,Places a unique identifier in each frame,Functions at Layer 2,VLAN Trunking,Comparing ISL and 802.1Q,ISL,802.1Q,Proprietary专有,Nonproprietary非专有,Encapsulated,Tagged,Protocol independent,Protocol dependent,Encapsulates the old frame in a new frame,Adds a field to the frame header,Trunking with ISL,Is a Cisco proprietary 专利protocol,Supports PVST,Uses an encapsulation process,Does not modify the original frame,ISL Encapsulation,Trunking with 802.1Q,An IEEE standard,Adds a 4-byte tag to the original frame,Additional tag includes a priority field,Does not tag frames that belong to the native VLAN,Supports Cisco IP telephonyThe 802.1Q Tagging Process,802.1Q Native VLAN,Native VLAN frames are carried over the trunk link untagged.,VLAN Ranges,VLAN Range,Use,0,4095,Reserved for system use only,1,Cisco default,21001,For Ethernet VLANs,10021005,Cisco defaults for FDDI and Token Ring,10064094,Ethernet VLANs only,unusable on specific legacy platforms,Trunking Configuration Commands,Configuring a Trunk,switchport trunk,switchport mode,switchport nonegotiate,Trunks can be configured statically or via DTP.,DTP provides the ability to negotiate the trunking method.,Switchport Mode Interactions,Dynamic Auto,Dynamic Desirable,Trunk,Access,Dynamic Auto,Access,Trunk,Trunk,Access,Dynamic Desirable,Trunk,Trunk,Trunk,Access,Trunk,Trunk,Trunk,Trunk,Not recommended,Access,Access,Access,Not recommended,Access,Note:Table assumes DTP is enabled at both ends.,show dtp interface,to determine current setting,How to Configure Trunking,Enter interface configuration mode.,Shut down interface.,Select the encapsulation(802.1Q or ISL).,Configure the interface as a Layer 2 trunk.,Specify the trunking native VLAN(for 802.1Q).,Configure the allowable VLANs for this trunk.,Use the,no shutdown,command on the interface to activate the trunking process.,Verify the trunk configuration.,802.1Q Trunk Configuration,Switch(config)#,interface fastethernet 5/8,Switch(config-if)#,shutdown,Switch(config-if)#,switchport trunk encapsulation dot1q,Switch(config-if)#,switchport trunk allowed vlan 1,5,11,1002-1005,Switch(config-if)#,switchport mode trunk,Switch(config-if)#,switchport trunk native vlan 99,Switch(config-if)#,switchport nonegotiate,Switch(config-if)#,no shutdown,Verifying the 802.1Q Configuration,Switch#show running-config interface fastethernet|gigabitethernet,slot/port,Switch#show interfaces fastethernet|gigabitethernet,slot/port,switchport|trunk,Switch#,show interfaces fastEthernet 5/8 switchport,Name:fa5/8,Switchport:Enabled,Administrative Mode:trunk,Operational Mode:trunk,Administrative Trunking Encapsulation:dot1q,Operational Trunking Encapsulation:dot1q,Negotiation of Trunking:Off,Access Mode VLAN:1(default),Trunking Native Mode VLAN:99(trunk_only),Trunking VLANs Enabled:,1,5,11,1002-1005,Pruning VLANs Enabled:2-1001,.,Verifying a 802.1Q Dynamic Trunk Link,Switch#,show running-config interface fastethernet 5/8,Building configuration.,Current configuration:,!,interface FastEthernet5/8,switchport mode dynamic desirable,switchport trunk encapsulation dot1q,Switch#,show interfaces fastethernet 5/8 trunk,Port Mode Encapsulation Status Native vlan,Fa5/8 desirable 802.1q trunking 99,Port Vlans allowed on trunk,Fa5/8 1,5,11,1002-1005,Port Vlans allowed and active in management domain,Fa5/8 1,5,1002-1005,Port Vlans in spanning tree forwarding state and not pruned,Fa5/8 1,5,1002-1005,ISL Trunk Configuration,Switch(config)#,interface fastethernet 2/1,Switch(config-if)#,shutdown,Switch(config-if)#,switchport trunk encapsulation isl,Switch(config-if)#,switchport trunk allowed vlan 1-5,1002-1005,Switch(config-if)#,switchport mode trunk,Switch(config-if)#,switchport nonegotiate,Switch(config-if)#,no shutdown,Verifying ISL Trunking,Switch#show running-config interface fastethernet|gigabitethernet,slot/port,Switch#show interfaces fastethernet|gigabitethernet,slot/port,switchport|trunk,Switch#,show interfaces fastethernet 2/1 trunk,Port Mode Encapsulation Status Native VLAN,Fa2/1 trunk isl trunking 99,Port VLANs allowed on trunk,Fa2/1 1-5,1002-1005,Port VLANs allowed and active in management domain,Fa2/1 1-2,1002-1005,Port VLANs in spanning tree forwarding state and not pruned,Fa2/1 1-2,1002-1005,Summary,Trunk links carry traffic from multiple VLANs.,ISL is Cisco proprietary and encapsulates the Layer 2 frames.,802.1Q is an IEEE standard for trunking,which implements a 4-byte tag.,The 802.1Q native VLANs forward frames without the tag.,VLAN numbers have specific ranges and purposes.,Various commands are used to configure and verify ISL and 802.1Q trunk links.,Allow only required VLANs over the trunk.,Defining VLANs,Propagating VLAN Configurations with VTP,The VTP Domain,Group of switches that exchange VLAN information,VLANs administered centrally at a chosen switch,The VTP Protocol,Advertises VLAN configuration information,Maintains VLAN configuration consistency throughout a common administrative domain,Sends advertisements on trunk ports only,VTP Modes,Client,Cannot create,change,or delete VLANs,Forwards advertisements,Synchronizes VLAN configurations,Does not save in NVRAM,Transparent,Creates,modifies,and deletes local VLANs,Forwards advertisements,Does not synchronize VLAN configurations,Saves configuration in NVRAM,Server(default mode),Creates,modifies,and deletes VLANs,Sends and forwards advertisements,Synchronizes VLAN configurations,Saves configuration in NVRAM,Pruning Disabled,Pruning Enabled,VTP Pruning,Uses bandwidth more efficiently by reducing unnecessary flooded traffic,Example:Station A sends broadcast;broadcast flooded only toward any switch with ports assigned to the red VLAN,VTP Operation,VTP advertisements are sent as multicast frames.,VTP servers and clients are synchronized to the latest revision number.,VTP advertisements are sent every 5 minutes or when there is a change.,VTP Configuration Commands,Configuring VTP,vtp domain,vtp mode,vtp password,Verifying VTP,show vtp status,show vtp counters,Configuring a VTP Management Domain,Configure each switch in the following order to avoid dynamic learning of the domain name:,VTP password,VTP domain name(case sensitive),VTP mode(server mode is the default),Configuring and Verifying VTP,Switch#show vlan brief,Displays a list of current VLANs,Switch(config)#vtp,mode,Sets the VTP mode to server,client,or transparent,Switch(config)#vtp domain,domain_name,Sets the VTP domain name,Switch#show vtp status,Displays the current settings for VTP,Sets the VTP password,Switch(config)#vtp password,password_string,Verifying the VTP Configuration,Switch#,show vtp status,VTP Version :2,Configuration Revision :28,Maximum VLANs supported locally:1005,Number of existing VLANs :17,VTP Operating Mode :Client,VTP Domain Name :BCMSN,VTP Pruning Mode :Enabled,VTP V2 Mode :Disabled,VTP Traps Generation :Disabled,MD5 digest :0 x45 0 x52 0 xB6 0 xFD 0 x63 0 xC8 0 x49 0 x80,Configuration last modified by 10.1.1.1 at 8-12-05 15:04:49,Switch#,Switch#show vtp status,Verifying the VTP Configuration(Cont.),Switch#,show vtp counters,VTP statistics:,Summary advertisements received :7,Subset advertisements received :5,Request advertisements received :0,Summary advertisements transmitted:997,Subset advertisements transmitted :13,Request advertisements transmitted:3,Number of config revision errors :0,Number of config digest errors :0,Number of V1 summary errors :0,VTP pruning statistics:,Trunk Join Transmitted Join Received Summary advts received from,non-pruning-capable device,-,Fa5/8 43071 42766 5,Switch#show vtp counters,Implementing Inter-VLAN Routing,Describing Routing Between VLANs,Inter-VLAN Routing with External Router,Single trunk link carries traffic for multiple VLANs to and from router.,Inter-VLAN Routing External Router Configuration Commands,Configure on subinterface,encapsulation dot1Q(or,isl,)10,ip address 10.10.1.1 255.255.255.0,Verify,show,vlan 10,show ip route,Inter-VLAN Routing on External Router:802.1Q Trunk Link,Inter-VLAN Routing on External Router:ISL Trunk Link,Verifying Inter-VLAN Routing,The,ping,command tests connectivity to remote hosts.,Verifying the Inter-VLAN Routing Configuration,Router#show ip interface brief,Displays the current IP configuration per VLAN,Router#show ip route,Displays IP route table information,Router#show vlan,Displays IP address on interfaces and current state of interface,