CCNA 2 - Capitulo 4

CCNA 2 - Capitulo 4

1. INTER-VLAN ROUTING

   • THREE INTER VLAN ROUTING - OPTIONS
     • ROUTER ON A STICK INTER VLAN ROUTING
       • IMPORTANT
         • PHYSICAL INTERFACE MUST BE ACTIVELY
           • NO SHUTDOWN
             • SUBINTERFACES INHERIT THE STATE OF PHYSICS.
         • MAY IMPACT THE TRAFFIC FLOW SPEED
       • CHARACTERISTICS ROAS
         • MEDIUM-SIZED NETWORK
         • DEDICATED ROUTER IS REQUIRED
         • ONE PHYSICAL ETHERNET INTERFACE
           • SUB-INTERFACES (SOFTWARE BASED)
             • ROUTE TRAFFIC BETWEEN MULTIPLE VLANs
             • CONFIGURED WITH AN IP AND VLAN ASSIGNMENT
         • SYNTAX IS THE PHYICAL INTERFACE FOLLOWED BY A PERIOD AND SUBINTERFACE NUMBER
       • NOTES
         • NOTES : ENABLE THE PHYSICAL INTERFACE . IF PHYSICAL INTERFACE IS DISABLE , ALL SUBINTERFACES ARE DISABLE
         • NOTES : SIMILAR TO FORTGATE ROUTING USING A PHYSICAL INTERFACE WITH MULTIPLE VLANS.
     • INTER VLAN ROUTING - LAYER 3 SWITCHES (SVIs)
       • ADVANTAGES OF USING LAYER 3 SWITCHES FOR INTER VLAN ?
         • INCRESEASE LINK
           • LAYER 2 ETHERCHANNELS CAN BE USED
         • MUCH FAST THAN ROUTER ON A STICK
           • HARDWARE SWITCHED AND ROUTED
         • LESS LATENCY
         • COMMONLY DEPLOYED IN A CAMPUS LAN THAN ROUTERs
       • MEDIUM SIZED ORGANIZATIONS
         • MORE COST
       • CAPABILITIES
         • ROUTE FROM ONE VLAN TO ANOTHER USING SVIs
         • CONVERT A LAYER 2 SWITCH TO A LAYER 3
       • ROUTING SCENARIO ON A LAYER 3 SWITCH
         • 2 - IF VLANs ARE TO BE REACHABLE BY OTHER LAYER 3 DEVICES
           • STEPS
             • 1 STEP - CONFIGURED THE ROUTED PORT
               • S1(CONFIG-IF)#NO SWITCHPORT
                 • IS A ROUTED PORT CREATED
               • NOTE
                 • MAKES THE SWITCH EFFECTIVELY LAYER 3.
             • 2 STEP - ENABLE ROUTING
               • S1(CONFIG)# IP ROUTING
             • 3 STEP - CONFIGURE ROUTING
               • MUST BE ADVERISED USING
                 • STATIC
                 • DYNAMIC ROUTING
             • 4 STEP - VERIFY ROUTING
               • S1#SHOW IP ROUTE | BEGIN GATEWAY
             • 5 STEP - VERIFY CONNECTIVITY
               • PING OTHER VLAN HOST
         • 1 - LAYER 3 SWITCH ROUTING INTERNAL ONLY
           • STEPS
             • 1 STEP - CREATE VLAN
               • S1(CONFIG)#VLAN 10
               • S1(CONFIG-VLAN)#NAME DATA
             • 2 STEP - CREATE THE SVI VLAN INTERFACES
               • S1(CONFIG)#INTERFACE VLAN 10
               • S1(CONFIG)#IP ADDRESS 172.16.10.254/24
             • 3 STEP - CONFIGURE ACCESS PORTS
               • S1(CONFIG)#SWITCHPORT ACCESS VLAN 10
             • 4 STEP - ENABLE IP ROUTIG
               • S1(CONFIG)#IP ROUTING
       • ROUTED VIA INTERNAL VLAN INTERFACES
       • NEED SVI EACH VLAN
     • LEGACY INTER VLAN ROUTING
       • IT DOES NOT SCALE WELL
         • ROUTER HAVE A LIMITED NUMBER OF PHYSICAL INTERFACES
       • ROUTERS WITH MULTIPLE ETHERNET INTERFACES
   • NOTES : HOSTS IN ONE VLAN CANNOT COMMUNICATE WITH HOSTS IN ANOTHER VLAN UNLESS A ROUTER
     • LAYER 3 SWITCH, OR FIREWALL PROVIDES INTER-VLAN ROUTING.
   • WHATS IS INTER VLAN ?
     • PROCESS OF FORWARDING NETWORK TRAFFIC FROM ONE VLAN TO ANOTHER VLAN

2. TROUBLESHOOTING INTER-VLAN ROUTING

   • MISSING VLANs
     • COMMAND
       • S1# SHOW VLAN BRIEF
       • S1#SHOW INTERFACES GIG0/1 SWITCHPORT
       • PING
     • CREATE OR RECREATE THE VLAN IF IT DOES NOT EXIST
     • ENSURE HOST PORT IS ASSIGNED CORRECT VLAN
     • NOTE
       • WHEN YOU DELETE A VLAN WITH PORT ASSIGNED
         • PORT BECOME INACTIVE (VLAN 1)
         • THE PORT IS NOT VISIBLE IN THE SHOW VLAN BRIEF COMMAND.
   • SWICH TRUNK PORT ISSUES
     • COMMAND
       • S1#SHOW INTERFACES TRUNK
       • S1#SHOW RUNNING-CONFIG
     • ENSURE TRUNKS ARE CONFIGURED CORRECTLY
     • ENSURE PORT IS A TRUNK PORT AND ENABLED
   • SWITCH ACCESS PORT ISSUES
     • COMMAD
       • S1#SHOW INTERFACES SWITCHPORT
       • S1#SHOW RUNNING-CONFIG INTERFACE G0/1
       • > IPCONFIG
     • ASSIGN CORRECT VLAN TO ACCESS PORT
     • ENSURE PORT IS AN ACCESS PORT AND ENABLED
     • HOST IS INCORECTLY CONFIGURED IN THE WRONG SUBNET
   • ROUTER CONFIGURATION ISSUES
     • COMMAND
       • R1#SHOW IP INTERFACE BRIEF
       • R1#SHOW INTERFACES
     • ROUTER SUBINTERFACE IPV4 ADDRESS IS INCORRECTLY CONFIGURED
     • ROUTER SUBINTERFACE IS ASSIGNED TO THE VLAN ID