NEWTWORKING 1 – FINAL “TO DO LIST”
trunk - any path carrying MORE THAN 1 vlan - typically between a router and a switch / and a switch and
a switch
dot1q - name of the standard of how frames get tagged with vlan information
encapsulation - layer 3 interacting with a layer 2 device, must encapsulate it
FIRST! When on a router, NO SHUT the serial interfaces. If you create a sub-interface without no
shutting the actual interface, you will run into a bug that will not allow the sub-interfaces to get turned
on.
ROUTERS
1
2
3
Name your router and set a password.
Set all of your IP's on the router for the serial interfaces, set clock rate if necessary, no shut
them, set descriptions.
Turn on (no shut) all of your fast ethernet interfaces ( “intfa0/0” – “no shut”, “intfa0/1” – “no
shut” etc until they are all on) - BEFORE ASSIGNING SUB INTERFACES.
4. Assign IP addresses to your sub-interfaces, "interface FA0/0.VLAN-ID", set IP address, and
“encapsulate dot1q VLAN-ID” – “no shut” - always ENCAPSULATE THEM! ALWAYS ENCAPSULATE VLANS!
5. Do not forget to create switch management VLANs (vlan 99), and encapsulate them. So when working
on a fast ethernet sub-interface, first create it, then assign IP, then ENCAPSULATE it, then no shut it.
6. Always remember to set your ROUTES on the router too, especially the default gateway. Be sure to
set a route for management VLANs too.
Troubleshooting : "show run", “show ip int bri”
HOSTS
1. As always, be sure to set the IP address and default gateway on all hosts to ensure connectivity and
give the ability to PING.
Troubleshooting : "ipconfig"
SWITCHES
1. Name the switch
2. Create all necessary VLANS, and show VLAN to make sure they exist. - from enable mode, "vlan data",
"vlan #" (get them all) DO NOT forget to create a VLAN for management of switches - always make this
vlan 99 or something the same across the topology to avoid confusion.
3. From global config, set the switch’s default gateway. “ip default-gateway (IP address of vlan 99 on
router)”
4. As you enter each interface (gigabit ethernet, fast Ethernet) remember to give a description.
5. Do all necessary commands on trunk lines - "switchport trunk encapsulation dot1q", "switchport
mode trunk" – remember trunks carry MORE than 1 VLAN, since we are creating management VLANs for
each switch, the trunks will always be between ROUTER/SWITCH --- and SWITCH/SWITCH
6. Do all necessary commands on NON trunk lines - "switchport mode access", "switchport access vlan
#" – the non-trunk lines will always be between SWITCH/HOSTS
7. Set VTP settings - "vtp domain NAME" - "vtp mode server/client" - "SHOW VTP STATUS" to check this!
8. Then Set IP addresses for the switch (always on the management VLAN) - from global config mode,
"int vlan 99", "ip add x.x.x.x x.x.x.x" and finally “NO SHUT”
Troubleshooting : “show vlan”, “show run”, “show ip int bri”, “show vtp status”
NETWORKING 1 – FINAL “TO DO LIST” CONTINUED
NOT PINGING??
show vlan on switch - make sure they exist on switches
show vtp status on switch – make sure your switches are on the right domain
show ip int bri on router and switch – make sure your routers interfaces are UP and the IP addresses are
correct
show run on router and switch – make sure your trunk/non trunk lines have the proper settings
show run on router and switch – make sure your default gateways and routes are all set properly
ipconfig on hosts – make sure your ip and default gateways are good