Tài liệu giảng dạy CCNA - module 04 chapter 14-LAN Switching Review and Configuring Cisco 2950 LAN Switches

Module 04 LAN Switching Chapter 14 LAN Switching Review and Configuring Cisco 2950 LAN Switches Objectives  Upon completion of this chapter, you will be able to perform the following tasks:  Describe Layer switching (bridging) operations  Describe the Catalyst 2950 switch operations  Configure Catalyst 2950 switch  Use show commands to verify Catalyst 2950 switch configuration and operations LAN SWITCHING REVIEW Three Switch Functions  Address learning  Forward/filter decision  Loop avoidance How Switches Learn Host Locations MAC address table A 0260.8c01.1111 C 0260.8c01.2222 B E0 E1 E2 E3 0260.8c01.3333 D 0260.8c01.4444 • Initial MAC address table is empty How Switches Learn Hosts Locations MAC address table E0: 0260.8c01.1111 A 0260.8c01.1111 C B E0 E1 E2 E3 0260.8c01.2222 0260.8c01.3333 D 0260.8c01.4444 • Station A sends a frame to Station C • Switch caches station A MAC address to port E0 by learning the source address of data frames • The frame from station A to station C is flooded out to all ports except port E0 (unknown unicasts are flooded) How Switches Learn Host Locations MAC address table E0: 0260.8c01.1111 E3: 0260.8c01.4444 A 0260.8c01.1111 C B E0 E2 0260.8c01.2222 E1 E3 0260.8c01.3333 D 0260.8c01.4444 • Station D sends a frame to station C • Switch caches station D MAC address to port E3 by learning the source Address of data frames • The frame from station D to station C is flooded out to all ports except port E3 (unknown unicasts are flooded) How Switches Filter Frames MAC address table A 0260.8c01.1111 C 0260.8c01.2222 E0: E2: E1: E3: E0 E2 0260.8c01.1111 0260.8c01.2222 0260.8c01.3333 0260.8c01.4444 B E1 X XE3 0260.8c01.3333 D 0260.8c01.4444  Station A sends a frame to station C  Destination is known, frame is not flooded Broadcast and Multicast Frames MAC address table A 0260.8c01.1111 C 0260.8c01.2222 E0: E2: E1: E3: 0260.8c01.1111 0260.8c01.2222 0260.8c01.3333 0260.8c01.4444 E0 E1 E2 E3 B 0260.8c01.3333 D 0260.8c01.4444 • Station D sends a broadcast or multicast frame • Broadcast and multicast frames are flooded to all ports other than the originating port Transmitting Frames through a Switch  Cut-through   Switch checks destination address and immediately begins forwarding frame Frame  Complete frame is received and checked before forwarding Frame Frame Fragment free (modified cut-through)—Cat1900 Default  Switch checks the first 64 bytes then immediately begins forwarding frame Frame  Store and forward Frame 10 Configuring the Switch  Catalyst 2950 IOS CLI (command-line interface) Web-based VSM (Visual Switch Manager) 13 Catalyst 2950 Default Configurations  IP address: 0.0.0.0  CDP: Enabled  100baseT port: Auto-negotiate duplex mode  1000baseT port: Auto-negotiate duplex mode  Spanning Tree: Enabled  Console password: none 14 Basic Administrative configurations  A switch should be given a hostname, and passwords should be set on the console and vty lines  switch(config)#hostname ALSwitch ALSwitch(config)#line console ALSwitch(config-line)#login ALSwitch(config-line)#password cisco ALSwitch(config-line)#line vty ALSwitch(config-line)#login ALSwitch(config-line)#password cisco 15 Configuring the Switch IP Address & default gateway To allow the switch to be accessible by Telnet and other TCP/IP applications, IP addresses and a default gateway should be set ALSwitch(config)#interface vlan ALSwitch(config-if)#ip address ip_add subnetmask ALSwitch(config)#ip default-gateway default_gateway 16 Speed and Duplex Options ASLSwitch(config)#interface f0/1 ASLSwitch(config-if)# duplex {auto | full| half} Speed {10|100|1000|auto|negociate} 17 Enable Web server  Intelligent networking devices can provide a web-based interface for configuration and management purposes  ALSwitch(config)#ip http server  ALSwitch(config)#ip http port 8080  Any additional software such as an applet, can be downloaded to the browser from the switch 18 Configuring Static MAC Addresses  It may be decided that it is desirable for a MAC address to be permanently assigned to an interface  To set a static MAC address entry for a switch:  Switch(config)#mac-address-table static FastEthernet vlan  To remove this entry use the no form of the command:  Switch(config)#no mac-address-table static interface FastEthernet vlan 19 Configure Port Security  ALSwitch(config)#interface f0/2  ALSwitch(config-if)#port security ?  action action to take for security violation  max-mac-count maximum mac address count   ALSwitch(config-if)#port security action ?  shutdown shut down the port from which security violation is detected  trap send snmp trap for security violaiton 20 Showing Duplex Options 21 Duplex Mismatches  The manually set duplex parameter differs between connected ports  The switch port is in autonegotiate and the attached port is set to full duplex with no autonegotiation capability causing the switch port to be in half-duplex mode 22 FCS and Late Collision Errors wg_sw_a#show interfaces Ethernet 0/1 is Enabled Hardware is Built-in 10Base-T Address is 0090.8673.3341 MTU 1500 bytes, BW 10000 Kbits 802.1d STP State: Forwarding Forward Transitions: Port monitoring: Disabled Unknown unicast flooding: Enabled Unregistered multicast flooding: Enabled Description: Duplex setting: Half duplex Back pressure: Disabled Receive Statistics Total good frames 44841 Total octets 4944550 Broadcast/multicast frames 31011 Broadcast/multicast octets 3865029 Good frames forwarded 44832 Frames filtered Runt frames No buffer discards Errors: FCS errors Alignment errors Giant frames Address violations 0 0 Transmit Statistics Total frames 404502 Total octets 29591574 Broadcast/multicast frames 390913 Broadcast/multicast octets 28478154 Deferrals Single collisions Multiple collisions Excessive collisions Queue full discards Errors: Late collisions Excessive deferrals Jabber errors Other transmit errors 23 Managing Mac Address Table wg_sw_a#show mac-address-table wg_sw_a#sh mac-address-table Number of permanent addresses : Number of restricted static addresses : Number of dynamic addresses : Address Dest Interface Type Source Interface List 00E0.1E5D.AE2F Ethernet 0/2 Dynamic All 00D0.588F.B604 FastEthernet 0/26 Dynamic All 00E0.1E5D.AE2B FastEthernet 0/26 Dynamic All 0090.273B.87A4 FastEthernet 0/26 Dynamic All 00D0.588F.B600 FastEthernet 0/26 Dynamic All 00D0.5892.38C4 FastEthernet 0/27 Dynamic All 24 Managing Configuration File To send the configuration to a TFTP server: wg_sw_a# copy nvram tftp://host/dst_file To download the configuration from a TFTP server: wg_sw_a# copy tftp://host/src_file nvram wg_sw_a#copy nvram tftp://10.1.1.1/wgswd.cfg Configuration upload is successfully completed wg_sw_a#copy tftp://10.1.1.1/wgswd.cfg nvram TFTP successfully downloaded configuration file 25 Clear NVRAM wg_sw_d#delete nvram • Resets the system configuration to factory defaults 26 Summary  After completing this chapter, you should be able to perform the following tasks:  Describe Layer switching (bridging) operations  Describe the Catalyst 2950 switch operations  Configure Catalyst 2950 switch  Use show commands to verify Catalyst 1900 switch configuration and operations 27 ... Point-to-point only • Attached to dedicated switched port • Requires full-duplex support on both ends • Collision free • Collision detect circuit disabled 11 CONFIGURING CISCO 2950 LAN SWITCHES. .. Switch(config)#mac-address-table static FastEthernet vlan  To remove this entry use the no form of the command:  Switch(config)#no mac-address-table... show commands to verify Catalyst 2950 switch configuration and operations LAN SWITCHING REVIEW Three Switch Functions  Address learning  Forward/filter decision  Loop avoidance How Switches