Show Menu
Cheatography

Routing Fundamentals Cheat Sheet (DRAFT) by

Routing Fundamentals

This is a draft cheat sheet. It is a work in progress and is not finished yet.

Factory Reset

R# sh run
Check: hostname, interface, ip, duplex
R# write erase
[confirm]
R# reload
Continue with config­uration dialog?: no
Check results:
# sh run
and
# show start
Config­uration
R# config t
R(config)# hostname [name]
R(config)# interface Gigabi­tEt­hernet[0/0]
R(conf­ig-if)# ip address [IP] [mask]
R(conf­ig-if)# duplex auto
R(conf­ig-if)# speed auto
R(conf­ig-if)# no shutdown
R(conf­ig-­if)­#line con 0
R(conf­ig-­line)# exec-t­imeout 30 0
R(conf­ig-­lin­e)#end
R# copy run start
 
R# sh ip route
R# show run | section interface
 
Disable interface FastEt­hernet 0/0
R(config)# interface fastEt­hernet 0/0
R(conf­ig-if)# shutdown
 

Configure IP addresses on Router

R#config t
R(config)# int f0/0
R(conf­ig-if)# ip address [IP] [mask]
R(conf­ig-if)# no shut
Verify routes have been added
R# show ip route
Verify the traffic path from PC to PC:
C:\>ping [IP]
and
C:\>tr­acert [IP]
Switch ports are not shutdown by default.

Static Routes

R# config t
R(config)# ip route [Desti­nation IP subnet] [Desti­nation IP subnet mask] [next-hop IP]
Verify connec­tivity by ping
Verify the traffic path from PC to PC:
C:\>ping [IP]
and
C:\>tr­acert [IP]
 
Remove static routes
R# config t
R(config)# no ip route [Dest IP subnet] [Dest IP subnet mask] [next-hop IP]

Summary Routes

R# config t
R(config)# ip route [IP subnet] [mask subnet] [next hop IP]
R(config)# end
R# sh ip route
Verify connec­tivity by ping

Default Route and Load Balancing

R# config t
R(config)# int f0/0
R(conf­ig-if)# ip add [IP] [mask]
R(conf­ig-if)# no shut
Ensure that each router has a route out to the internet
R(config)# ip route 0.0.0.0 0.0.0.0 [next hop IP]

Routing Protocol

Basic RIPv1 config­uration + Enable RIPv2
R(config)# router rip
R(conf­ig-­rou­ter)# version 2
Enable RIPv2
R(conf­ig-­rou­ter)# no auto-s­ummary
R(conf­ig-­rou­ter)# network [ip subnet]
R# show ip route
Check that RIP routes have been added
R#sh ip rip database
View the RIP database
 
Inject the default static route
R(config)# router rip
R(conf­ig-­rou­ter)# defaul­t-i­nfo­rmation originate
 
Debug the routing protocol updates
R# debug ip rip
R# undebug all
Turn off all debugging
 
Basic EIGRP config­uration
R(config)# router eigrp 100
// R(conf­ig-­rou­ter)# network [IP subnet]
R(conf­ig-­rou­ter)# no auto-s­ummary
R(conf­ig-­rou­ter)# network [IP] [mask]
 
R(config)# no router eigrp 100
remove/ disable EIGRP
 
R# sh ip eigrp neighbors
 
Loopback config­uration
R(conf­ig)­#in­terface loopback0

Adjace­ncies and Passive Interfaces

R# show ip eigrp neighbors
Verify that R"x" has establ­ished EIGRP adjace­ncies with R"y"
 
R(conf­ig-if)# router eigrp 100
Configure the loopback interface and the link as passive interfaces
R(conf­ig-­rou­ter)# passiv­e-i­nte­rface loopback0
R(conf­ig-­rou­ter)# passiv­e-i­nte­rface fastet­her­net1/1

Basic OSPF config­Â­ur­ation

R(config)# router ospf 1
R(conf­ig-­rou­ter)# network [IP subnet] [wildcard mask] area 0
Ex: network 10.0.0.0 0.255.2­55.255 area 0
 
OSPF Verifi­cation
R# sh run | section ospf
show run | section ospf
R# sh ip protocols
show ip protocols
R# show ip ospf interface brief
show ip ospf interface brief
R# show ip ospf neighbor
show ip ospf neighbor
R# show ip ospf database
show ip ospf database
R# show ip route
show ip route
 
Remove/ Disable OSPF
R(config)# no router ospf 1
 
OSPF Router ID
R# sh ip int brief
Check Loopback or No Loopback
R# show ip protocols
 
R(conf­ig-­rou­ter)# router ospf 1
Manually Configured
R#(con­fig­-ro­uter)# router-id 2.2.2.2
R# clear ip ospf process
R# show ip protocols
 
Passive Interface Config­uration
R1(con­fig­-ro­uter)# router ospf 1
R1#(co­nfi­g-r­outer)# passiv­e-i­nte­rface [loopback 0]
ex2: R#(con­fig­-ro­uter)# passiv­e-i­nte­rface f2/0
 
R1(con­fig­-ro­uter)# router ospf 1
R1#(co­nfi­g-r­outer)# passiv­e-i­nte­rface default
set passive interface as the default
R1#(co­nfi­g-r­outer)# no passiv­e-i­nte­rface [f0/0]
 
Default Route Injection
R4(con­fig)#ip route 0.0.0.0 0.0.0.0 203.0.1­13.2
R4(con­fig­)#r­outer ospf 1
R4(con­fig­-ro­ute­r)#­def­aul­t-i­nfo­rmation originate
---> R1#sh ip route
Default Route Injection Verifi­cation
 
OSPD Areas
R(config)# router ospf 1
R(conf­ig-­rou­ter)# network [IP subnet] [wildcard mask] area 0