{"id":2126,"date":"2019-07-19T20:17:46","date_gmt":"2019-07-19T20:17:46","guid":{"rendered":"http:\/\/wiki.thomasandsofia.com\/?p=2126"},"modified":"2021-12-13T10:47:44","modified_gmt":"2021-12-13T10:47:44","slug":"section-14-cisco-router-and-switch-basics","status":"publish","type":"post","link":"https:\/\/wiki.thomasandsofia.com\/?p=2126","title":{"rendered":"Section 14: Cisco Router and Switch Basics"},"content":{"rendered":"<p><a href=\"http:\/\/wiki.thomasandsofia.com\/?p=2113\">&lt; Section 13<\/a> | <a href=\"\/course-introduction\/\">Home<\/a> | <a href=\"http:\/\/wiki.thomasandsofia.com\/?p=2141\">Section 15 &gt;<\/a><\/p>\n<p>37% Complete<\/p>\n<h1><span style=\"color: #0000ff;\">Including CCNA starting here.\u00a0 Appears to be EXACTLY the same course.<\/span><\/h1>\n<h1>75: Cisco Router and Switch Basics &#8211; Intro<\/h1>\n<p>77: CCNA: <a href=\"https:\/\/www.udemy.com\/course\/ccna-complete\/learn\/lecture\/7367248#overview\" target=\"_blank\" rel=\"noopener\">https:\/\/www.udemy.com\/course\/ccna-complete\/learn\/lecture\/7367248#overview<\/a><\/p>\n<p><a href=\"https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605258#content\" target=\"_blank\" rel=\"noopener\">https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605258#content<\/a><\/p>\n<h1>76: Cisco Router and Switch Configuration<\/h1>\n<p><a href=\"https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605260#content\" target=\"_blank\" rel=\"noopener\">https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605260#content<\/a><\/p>\n<h2>Router IP Addresses<\/h2>\n<ul>\n<li>A Router provides connectivity between different IP subnets<\/li>\n<li>An IP address must be configured on the interfaces in each subnet.<\/li>\n<\/ul>\n<h3>Configuring an IP on a Router<\/h3>\n<pre>Router&gt;enable\r\nRouter#show running-config\r\n...\r\ninterface FastEthernet0\/0\r\n no ip address\r\n shutdown\r\n duplex auto\r\n speed auto\r\n!\r\ninterface FastEthernet0\/1\r\n no ip address\r\n shutdown\r\n duplex auto\r\n speed auto\r\n!\r\n...\r\n\r\nRouter#configure terminal\r\nRouter(config)#interface fastEthernet0\/0\r\nRouter(config-if)ip address 10.0.0.1 255.255.255.0\r\nRouter(config-if)no shutdown\r\nRouter(config-if)end\r\nRouter#show ip interface brief\r\nInterface                  IP-Address      OK? Method Status                Prol\r\nFastEthernet0\/0            10.0.0.1        YES manual up                    up\r\nFastEthernet0\/1            unassigned      YES NVRAM  administratively down dow\r\nATM0\/0\/0                   unassigned      YES NVRAM  administratively down dow\r\nSerial0\/1\/0                unassigned      YES NVRAM  administratively down dow\r\nSerial0\/1\/1                unassigned      YES NVRAM  administratively down dow\r\n<\/pre>\n<h2>Switch Management IP Address<\/h2>\n<ul>\n<li>A Layer 2 Switch is not IP routing aware<\/li>\n<li>It\u00a0 does however support a single IP address for management<\/li>\n<li>This IP address and subnet mask is configured on the Switched Virtual Interface (SVI) for the default VLAN 1.<\/li>\n<li>A default gateway also needs to be configured to allow connectivity to other subnets.<\/li>\n<\/ul>\n<pre>Switch(config)#interface vlan 1\r\nSwitch(config-if)#ip address 10.0.0.101 255.255.255.0\r\nSwitch(config-if)#no shutdown\r\nSwitch(config-if)#exit\r\nSwitch(config)#ip default-gateway 10.0.0.1<\/pre>\n<p><b>Note: On Switches, Interfaces are UP (not shutdown) by default, so adding &#8216;no shutdown&#8217; really is not required here.<\/b><\/p>\n<h2>Lab Example<\/h2>\n<p><a href=\"http:\/\/wiki.thomasandsofia.com\/wp-content\/uploads\/2019\/07\/alab1.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2127\" src=\"http:\/\/wiki.thomasandsofia.com\/wp-content\/uploads\/2019\/07\/alab1.png\" alt=\"\" width=\"460\" height=\"115\" srcset=\"https:\/\/wiki.thomasandsofia.com\/wp-content\/uploads\/2019\/07\/alab1.png 460w, https:\/\/wiki.thomasandsofia.com\/wp-content\/uploads\/2019\/07\/alab1-300x75.png 300w, https:\/\/wiki.thomasandsofia.com\/wp-content\/uploads\/2019\/07\/alab1-150x38.png 150w\" sizes=\"auto, (max-width: 460px) 100vw, 460px\" \/><\/a><\/p>\n<h3>Router Setup<\/h3>\n<pre>Router&gt;enable\r\nRouter#configure terminal\r\nRouter(config)#interface fastEthernet 0\/0\r\nRouter(config-if)#ip address 192.168.0.1 255.255.255.0\r\nRouter(config-if)#no shutdown<\/pre>\n<h3>Switch Setup<\/h3>\n<pre>Switch&gt;enable\r\nSwitch#configure terminal\r\nSwitch(config)#interface vlan 1\r\nSwitch(config-if)#ip address 192.168.0.10 255.255.255.0\r\nSwitch(config-if)#no shutdown\r\nSwitch(config-if)#end\r\nSwitch#ping 192.168.0.1\r\n!!!!!\r\nSuccess rate is 100 percent...<\/pre>\n<h4>Configure Switch to reach other networks<\/h4>\n<pre>Switch#configure terminal\r\nSwitch(config)#ip default-gateway 192.168.0.1<\/pre>\n<h2>Configure the Hostname<\/h2>\n<p>This works for both Routers and Switches (and likely any other Cisco device)<\/p>\n<pre>Switch(config)#hostname SW1\r\nSW1(config)#<\/pre>\n<h2>Configure an Interface Descriptions<\/h2>\n<p>This works for both Routers and Switches (and likely any other Cisco device)<\/p>\n<p>This does NOT show up during show ip interface brief, but it does show up in the running-config<\/p>\n<pre>SW1(config)#interface FastEthernet 0\/0\r\nSW1(config-if)#description Link to R1<\/pre>\n<h1>77: The Initial Setup Wizard<\/h1>\n<p><a href=\"https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605262#content\" target=\"_blank\" rel=\"noopener\">https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605262#content<\/a><\/p>\n<h2>Router<\/h2>\n<p>You will see the &#8220;System Configuration Dialog&#8221; prompt when you:<\/p>\n<ul>\n<li>First boot a Router or Switch that has not been configured<\/li>\n<li>By running &#8216;setup&#8217; from the enable prompt<\/li>\n<\/ul>\n<p>In the real world, you will likely never see this used, but you might get tested on it, so you should know what it is going to do.<\/p>\n<ul>\n<li>Enter host name [Router]: R1<\/li>\n<li>Enter enable secret: Pas$W0rd\n<ul>\n<li>This password will be stored encrypted in the running config.<\/li>\n<\/ul>\n<\/li>\n<li>Enter enable password: Pas$W0rd2\n<ul>\n<li>This cannot match the enable secret password.<\/li>\n<li>To my knowledge, this password is disabled if a secret password had been enabled&#8230;<\/li>\n<\/ul>\n<\/li>\n<li>Enter virtual terminal password: Pas$W0rd3\n<ul>\n<li>Used when telnetting in over a network interface.<\/li>\n<\/ul>\n<\/li>\n<li>Configure SNMP Network Management? [no]: no\n<ul>\n<li>Can be configured later.\u00a0\u00a0 Think this is a lengthy subject.<\/li>\n<\/ul>\n<\/li>\n<li>Enter interface name used to connect to the management network from the above interface summary: fastethernet0\/0\n<ul>\n<li>The software will provide a list of the available interfaces before prompting.<\/li>\n<li>You cannot use shortcut names.\u00a0 You must type the entire interface name.<\/li>\n<\/ul>\n<\/li>\n<li>Configuring interface FastEthernet0\/0:\n<ul>\n<li>Operate in full-duplex mode? [no]: yes<\/li>\n<li>Configure IP on this interface? [no]: yes\n<ul>\n<li>IP address for this interface: 10.0.0.1\n<ul>\n<li>Do NOT enter the subnet mask here!\u00a0 What??<\/li>\n<\/ul>\n<\/li>\n<li>Subnet mask for this interface [255.0.0.0]: 255.255.255.0\n<ul>\n<li>Notice that it defaulted to the default net mask for the IP&#8217;s Class!<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<li>[0] Go to the IOS command prompt without saving this config.<\/li>\n<li>[1] Return back to the setup without saving this config.<\/li>\n<li>[2] Save this configuration to nvram and exit.<\/li>\n<li>Enter your selection [2]: 2\n<ul>\n<li>This saves your edits to the startup-config<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h2>Switch<\/h2>\n<ul>\n<li>Would you like to enter the initial configuration dialog? [yes\/no]: yes<\/li>\n<li>Would you like to enter basic management setup? [yes\/no]: yes\n<ul>\n<li>Enter host name [Switch]: SW1<\/li>\n<li>Enter enable secret: cisco<\/li>\n<li>Enter enable password: cisco-kid<\/li>\n<li>Enter virtual terminal password: cisco<\/li>\n<li>Configure SNMP Network Management? [no]: no (or just press [Enter])<\/li>\n<\/ul>\n<\/li>\n<li>Enter interface name used to connect to the management network from the above interface summary: vlan1<\/li>\n<li>Configuring interface Vlan1:\n<ul>\n<li>Configure IP on this interface? [yes]: yes\n<ul>\n<li>IP address for this interface: 10.0.0.101<\/li>\n<li>Subnet mask for this interface [255.0.0.0] : 255.255.255.0<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<li>Would you like to enable as a cluster command switch? [yes\/no]: no<\/li>\n<\/ul>\n<p>The setup wizard does not setup a default gateway.\u00a0 You&#8217;ll need to do this manually.<\/p>\n<pre>SW1&gt;enable\r\nSW1#configure terminal\r\nSW1(config)#ip default-gateway 10.0.0.1<\/pre>\n<h1>78: Speed and Duplex Settings<\/h1>\n<p><a href=\"https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605266#overview\" target=\"_blank\" rel=\"noopener\">https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605266#overview<\/a><\/p>\n<h2>Interface Speed and Duplex<\/h2>\n<ul>\n<li>Speed and Duplex are set to Auto by default<\/li>\n<li>Both sides of a link should auto-negotiate to full duplex and the fastest available speed<\/li>\n<li>Best practice is to manually set the speed and duplex on ports connected to another network infrastructure device such as:\n<ul>\n<li>Firewalls<\/li>\n<li>Switches<\/li>\n<li>Routers<\/li>\n<li>Servers\n<ul>\n<li>This may improve reliability but auto should work also.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<\/li>\n<li>It is important to set matching speed and duplex settings on both sides of the link.\n<ul>\n<li>Both sides set &#8216;auto&#8217; or both sides set manually.<\/li>\n<li>Do not set one &#8216;auto&#8217; and the other manually.<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2>Setting Manually<\/h2>\n<pre>SW1(config)#interface fastethernet 0\/1\r\nSW1(config-if)#duplex ?\r\n  auto  Enable AUTO duplex configuration\r\n  full  Force full duplex operation\r\n  half  Force half-duplex operation\r\nSW1(config-if)#speed ?\r\n  10    Force 10 Mbps operation\r\n  100   Force 100 Mbps operation\r\n  auto  Enable AUTO speed configuration<\/pre>\n<h2>Verification Commands<\/h2>\n<h3>show running-config<\/h3>\n<h3>show ip interface brief<\/h3>\n<pre>Interface                  IP-Address      OK? Method Status                Protocol\r\nVlan1                      10.0.0.101      YES manual up                    up      \r\nFastEthernet0\/1            unassigned      YES unset  up                    up      \r\nFastEthernet0\/2            unassigned      YES unset  down                  down    \r\n...\r\nFastEthernet0\/12           unassigned      YES unset  down                  down    \r\nFastEthernet0\/13           unassigned      YES unset  up                    up      \r\nFastEthernet0\/14           unassigned      YES unset  down                  down   \r\n...\r\nFastEthernet0\/23           unassigned      YES unset  down                  down    \r\nFastEthernet0\/24           unassigned      YES unset  down                  down    \r\nGigabitEthernet0\/1         unassigned      YES unset  down                  down    \r\nGigabitEthernet0\/2         unassigned      YES unset  down                  down<\/pre>\n<h3>show running-config interface vlan 1<\/h3>\n<pre>Building configuration...\r\n\r\nCurrent configuration : 79 bytes\r\n!\r\ninterface Vlan1\r\n ip address 10.0.0.101 255.255.255.0\r\n no ip route-cache\r\nend<\/pre>\n<h3>show interfaces vlan 1<\/h3>\n<pre>Vlan1 is up, line protocol is up \r\n  Hardware is CPU Interface, address is 0015.6239.5000 (bia 0015.6239.5000)\r\n  Internet address is 10.0.0.101\/24\r\n  MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec, \r\n     reliability 255\/255, txload 1\/255, rxload 1\/255\r\n  Encapsulation ARPA, loopback not set\r\n  ARP type: ARPA, ARP Timeout 04:00:00\r\n  Last input 00:00:00, output never, output hang never\r\n  Last clearing of \"show interface\" counters never\r\n  Input queue: 0\/75\/0\/0 (size\/max\/drops\/flushes); Total output drops: 0\r\n  Queueing strategy: fifo\r\n  Output queue: 0\/40 (size\/max)\r\n  5 minute input rate 1000 bits\/sec, 1 packets\/sec\r\n  5 minute output rate 3000 bits\/sec, 2 packets\/sec\r\n     1036505 packets input, 173050963 bytes, 0 no buffer\r\n     Received 278184 broadcasts (0 IP multicast)\r\n     0 runts, 0 giants, 0 throttles\r\n     0 input errors, 0 CRC, 0 frame, 0 overrun, 91 ignored\r\n     1556025 packets output, 950236569 bytes, 0 underruns\r\n     0 output errors, 4 interface resets\r\n     0 output buffer failures, 0 output buffers swapped out<\/pre>\n<h3>show version<\/h3>\n<pre>Cisco Internetwork Operating System Software \r\nIOS (tm) C2950 Software (C2950-I6K2L2Q4-M), Version 12.1(22)EA14, RELEASE SOFTWARE (fc1)\r\nTechnical Support: http:\/\/www.cisco.com\/techsupport\r\nCopyright (c) 1986-2010 by cisco Systems, Inc.\r\nCompiled Tue 26-Oct-10 10:35 by nburra\r\nImage text-base: 0x80010000, data-base: 0x80680000\r\n\r\nROM: Bootstrap program is C2950 boot loader\r\n\r\nSwitch uptime is 1 week, 1 day, 18 hours, 39 minutes\r\nSystem returned to ROM by power-on\r\nSystem image file is \"flash:\/c2950-i6k2l2q4-mz.121-22.EA14.bin\"\r\n\r\n\r\nThis product contains cryptographic features and is subject to United\r\nStates and local country laws governing import, export, transfer and\r\nuse. Delivery of Cisco cryptographic products does not imply\r\nthird-party authority to import, export, distribute or use encryption.\r\nImporters, exporters, distributors and users are responsible for\r\ncompliance with U.S. and local country laws. By using this product you\r\nagree to comply with applicable laws and regulations. If you are unable\r\nto comply with U.S. and local laws, return this product immediately.\r\n          \r\nA summary of U.S. laws governing Cisco cryptographic products may be found at:\r\nhttp:\/\/www.cisco.com\/wwl\/export\/crypto\/tool\/stqrg.html\r\n\r\nIf you require further assistance please contact us by sending email to\r\nexport@cisco.com.\r\n\r\ncisco WS-C2950G-24-EI (RC32300) processor (revision L0) with 19911K bytes of memory.\r\nProcessor board ID FOC0934Z9V8\r\nLast reset from system-reset\r\nRunning Enhanced Image\r\n24 FastEthernet\/IEEE 802.3 interface(s)\r\n2 Gigabit Ethernet\/IEEE 802.3 interface(s)\r\n\r\n32K bytes of flash-simulated non-volatile configuration memory.\r\nBase ethernet MAC Address: 00:15:62:39:50:00\r\nMotherboard assembly number: 73-7280-05\r\nPower supply part number: 34-0965-01\r\nMotherboard serial number: FOC09331L5T\r\nPower supply serial number: DAB0933EAAL\r\nModel revision number: L0\r\nMotherboard revision number: A0\r\nModel number: WS-C2950G-24-EI\r\nSystem serial number: FOC0934Z9V8\r\nConfiguration register is 0xF<\/pre>\n<p>&nbsp;<\/p>\n<h1>79: CDP and LLDP<\/h1>\n<p><a href=\"https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605272#content\" target=\"_blank\" rel=\"noopener\">https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605272#content<\/a><\/p>\n<h2>CDP Cisco Discovery Protocol<\/h2>\n<ul>\n<li>CDP is a proprietary Layer 2 protocol<\/li>\n<li>It is used to share information with other directly connected Cisco equipment, such as the operating system version and IP address<\/li>\n<li>This aids in troubleshooting by allowing administrators to map out how Cisco devices are connected to each other.<\/li>\n<li>It is enabled by default on most Cisco devices<\/li>\n<li>it works at Layer 2, so it is not necessary for the device to have an IP address.<\/li>\n<\/ul>\n<h3>Commands<\/h3>\n<h4>Enable CDP<\/h4>\n<pre>(config)#cdp run<\/pre>\n<h4>Disable CDP<\/h4>\n<pre>(config)#no cdp run<\/pre>\n<h4>Disable CDP for a specific interface<\/h4>\n<p>Good for enabling on an internal network, but disabling for external networks.<\/p>\n<pre>(config-if)#no cdp enable<\/pre>\n<h4>show cdp<\/h4>\n<pre>Global CDP information:\r\n\tSending CDP packets every 60 seconds\r\n\tSending a holdtime value of 180 seconds\r\n\tSending CDPv2 advertisements is  enabled<\/pre>\n<h4>show cdp neighbors<\/h4>\n<pre>Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge\r\n                  S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone, \r\n                  D - Remote, C - CVTA, M - Two-port Mac Relay \r\n\r\nDevice ID        Local Intrfce     Holdtme    Capability  Platform  Port ID\r\nSwitch           Fas 0\/0            147             S I   WS-C2950G Fas 0\/1<\/pre>\n<h4>show cdp neighbors detail<\/h4>\n<pre>-------------------------\r\nDevice ID: Switch\r\nEntry address(es): \r\n  IP address: 10.0.0.101\r\nPlatform: cisco WS-C2950G-24-EI,  Capabilities: Switch IGMP \r\nInterface: FastEthernet0\/0,  Port ID (outgoing port): FastEthernet0\/1\r\nHoldtime : 155 sec\r\n\r\nVersion :\r\nCisco Internetwork Operating System Software \r\nIOS (tm) C2950 Software (C2950-I6K2L2Q4-M), Version 12.1(22)EA14, RELEASE SOFTWARE (fc1)\r\nTechnical Support: http:\/\/www.cisco.com\/techsupport\r\nCopyright (c) 1986-2010 by cisco Systems, Inc.\r\nCompiled Tue 26-Oct-10 10:35 by nburra\r\n\r\nadvertisement version: 2\r\nProtocol Hello:  OUI=0x00000C, Protocol ID=0x0112; payload len=27, value=00000000FFFFFFFF010221FF000000000000001562395000FF0000\r\nVTP Management Domain: ''\r\nNative VLAN: 1\r\nDuplex: full<\/pre>\n<h2>LLDP Link Layer Discovery Protocol<\/h2>\n<ul>\n<li>Came much later than CDP so may not be available on all devices<\/li>\n<li>Open source standard for various vendors<\/li>\n<\/ul>\n<p>Commands<\/p>\n<ul>\n<li>(config)# lldp run<\/li>\n<li>(config)#no lldp run<\/li>\n<li>(config)#no lldp transmit<\/li>\n<li>(config)#no lldp receive<\/li>\n<li>#show lldp<\/li>\n<li>#show lldp neighbors<\/li>\n<li>#show lldp neighbors detail<\/li>\n<\/ul>\n<h1>80: Basic Layer 1 and 2 Troubleshooting<\/h1>\n<p><a href=\"https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605274#overview\" target=\"_blank\" rel=\"noopener\">https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605274#overview<\/a><\/p>\n<h2>Layer 1 Troubleshooting<\/h2>\n<ul>\n<li>Copper and Fibre cables are liable to break if not handled correctly.<\/li>\n<li>The interface is administratively shut down<\/li>\n<li>The cable is disconnected on either or both ends<\/li>\n<li>The device on the other end of the cable is powered off.<\/li>\n<li>Broken connectors which cause loose connections<\/li>\n<li>Bent or stretched cables which lead to broken wires or fibres.<\/li>\n<li>Electro-Magnetic Interference (EMI) sources such as motors or microwaves which cause errors in transmission.\u00a0 (Newer cables are less susceptible to this)<\/li>\n<\/ul>\n<h3>#show ip interface brief<\/h3>\n<ul>\n<li>administratively down: enable the interface by running &#8216;no shutdown&#8217;<\/li>\n<li>down\/down: Indicates a Layer 1 issues.\u00a0 Check the interface is cabled at both ends and the device on the other side is powered on.<\/li>\n<li>up\/down: Indicates a Layer 2 issue or speed mismatch.\u00a0 Check interface configurations matches on both sides of the link.<\/li>\n<\/ul>\n<h3>#show interface<\/h3>\n<ul>\n<li>If the interface is reporting an excessive amount of errors, it could be either a Layer 1 or Layer 2 issue.<\/li>\n<li>Check the integrity of the cable<\/li>\n<li>Check the configurations match on both sides of the link.<\/li>\n<\/ul>\n<h2>Speed and Duplex Mismatches<\/h2>\n<ul>\n<li>Incorrect speed settings can cause the interface to operate below its maximum speed.<\/li>\n<li>Speed mismatches will typically bring the interface down<\/li>\n<li>The interface will typically stay up with duplex mismatches but performance will be terrible because of collisions.<\/li>\n<li>The &#8216;show interface&#8217; command will report an excessively high number of errors in this case.<\/li>\n<li>Both sides of a link must be set the same, as either auto or manually configured\n<ul>\n<li>Cisco devices default to auto<\/li>\n<li>If one side is set to auto and the other is manually configured, this will often result in a mismatch<\/li>\n<li>Best practice is to manually configure ports attached to other internal network infrastructure devices or servers.<\/li>\n<li>Remember to manually configure both sides of the link.<\/li>\n<\/ul>\n<\/li>\n<li>If a device has issues with auto negotiating speed or duplex, manually configuring both sides will normally resolve the problem.<\/li>\n<\/ul>\n<h1>81: Basic Layer 1 and 2 Troubleshooting &#8211; Lab Demo<\/h1>\n<p><a href=\"https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605278#overview\" target=\"_blank\" rel=\"noopener\">https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605278#overview<\/a><\/p>\n<h2>Speed and Duplex &#8211; CDP<\/h2>\n<p>CDP should detect a duplex mismatch<\/p>\n<ul>\n<li>Speed mismatch should bring the interface down.<\/li>\n<li>Duplex mismatch should not bring the interface down, but will cause horrible performance issues due to collisions.<\/li>\n<\/ul>\n<h1>82: Basic Layer 1 and 2 Troubleshooting &#8211; Lab<\/h1>\n<p><a href=\"https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605282#overview\" target=\"_blank\" rel=\"noopener\">https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605282#overview<\/a><\/p>\n<p><a href=\"http:\/\/wiki.thomasandsofia.com\/wp-content\/uploads\/2019\/07\/14-Cisco-Router-and-Switch-Basics.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2137\" src=\"http:\/\/wiki.thomasandsofia.com\/wp-content\/uploads\/2019\/07\/14-Cisco-Router-and-Switch-Basics.jpg\" alt=\"\" width=\"934\" height=\"273\" srcset=\"https:\/\/wiki.thomasandsofia.com\/wp-content\/uploads\/2019\/07\/14-Cisco-Router-and-Switch-Basics.jpg 934w, https:\/\/wiki.thomasandsofia.com\/wp-content\/uploads\/2019\/07\/14-Cisco-Router-and-Switch-Basics-300x88.jpg 300w, https:\/\/wiki.thomasandsofia.com\/wp-content\/uploads\/2019\/07\/14-Cisco-Router-and-Switch-Basics-768x224.jpg 768w, https:\/\/wiki.thomasandsofia.com\/wp-content\/uploads\/2019\/07\/14-Cisco-Router-and-Switch-Basics-150x44.jpg 150w\" sizes=\"auto, (max-width: 934px) 100vw, 934px\" \/><\/a><\/p>\n<p><a href=\"http:\/\/wiki.thomasandsofia.com\/wp-content\/uploads\/2019\/07\/14-Cisco-Router-and-Switch-Basics-Lab-Exercise.pdf\">14 Cisco Router and Switch Basics Lab Exercise<\/a><\/p>\n<p><a href=\"http:\/\/wiki.thomasandsofia.com\/wp-content\/uploads\/2019\/07\/14-Cisco-Router-and-Switch-Basics-Answer-Key.pdf\">14 Cisco Router and Switch Basics Answer Key<\/a><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>&lt; Section 13 | Home | Section 15 &gt; 37% Complete Including CCNA starting here.\u00a0 Appears to be EXACTLY the same course. 75: Cisco Router and Switch Basics &#8211; Intro 77: CCNA: https:\/\/www.udemy.com\/course\/ccna-complete\/learn\/lecture\/7367248#overview https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605258#content 76: Cisco Router and Switch Configuration https:\/\/www.udemy.com\/cisco-icnd1\/learn\/lecture\/8605260#content Router IP Addresses A Router provides connectivity between different IP subnets An IP address ..<\/p>\n<div class=\"clear-fix\"><\/div>\n<p><a href=\"https:\/\/wiki.thomasandsofia.com\/?p=2126\" title=\"read more...\">Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[74,2,1],"tags":[],"class_list":["post-2126","post","type-post","status-publish","format-standard","hentry","category-ccna","category-networking","category-uncategorized"],"_links":{"self":[{"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=\/wp\/v2\/posts\/2126","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2126"}],"version-history":[{"count":16,"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=\/wp\/v2\/posts\/2126\/revisions"}],"predecessor-version":[{"id":3607,"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=\/wp\/v2\/posts\/2126\/revisions\/3607"}],"wp:attachment":[{"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2126"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2126"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wiki.thomasandsofia.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2126"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}