Here are the configuration for Basic Router Configuration
When You Open a new router you will see
Router> This is called user mode;
then you type en=enable to get to enable mode
Router# This is called privilege mode
Hint: Always always always you must go to config t mode that will take you to Global configuration mode
Router#config t
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#
Now I will show you how you give a HostName and IP address to the interface like F0/0
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Enter configuration commands, one per line. End with CNTL/Z.Router(config)#hostname R1
R1(config)#int
R1(config)#interface f0/0
R1(config-if)#
as we see I am in Interface mode of F0/0 or my router
Now I will give an IP address
R1(config-if)#
R1(config-if)#
R1(config-if)#ip address ?
A.B.C.D IP address
dhcp IP Address negotiated via DHCP
R1(config-if)#ip address 10.10.10.100
% Incomplete command.
R1(config-if)#ip address 10.10.10.100 ?
A.B.C.D IP subnet mask
R1(config-if)#ip address 10.10.10.100 255.255.255.0
R1(config-if)#
Let’s try to ping pc1 from this position
R1(config-if)#ping 10.10.10.1
^
% Invalid input detected at ‘^’ marker.
Any time you see above it means you are in wrong mode; so
Type exit to go back one mode
R1(config)#ping 10.10.10.1
^
% Invalid input detected at ‘^’ marker.
R1(config)#
As we see Ping does not work in this mode
Let’s go back one more ; so type exit
R1#ping 10.10.10.1
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.10.10.1, timeout is 2 seconds:
…..
Success rate is 0 percent (0/5)
R1#
So I see the ping works only in user mode and privilege mode
R1>
R1#
Ping and show does not work in config mode or interface mode
As we see the ping works; but I get no response; why?
Since by default all interface are in shut down mode
Hint: You must always memorize this commands
Here is before my change ( Up and Up)
R1#show ip int brief
Interface | IP-Address | OK? | Method | Status | Protocol |
FastEthernet0/0 | 10.10.10.100 | YES | manual administratively | down | down |
FastEthernet0/1 | unassigned | YES | unset administratively | down | down |
Vlan1 | unassigned | YES | unset administratively | down | down |
R1#
Now to solve the problem; I must go to interface mode and give no shut
R1(config)#int f0/0
R1(config-if)#no shut
%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up
R1(config-if)#
Now let’s check show IP int brief after this
R1#show ip int brief
Interface | IP-Address | OK? | Method | Status | Protocol |
FastEthernet0/0 | 10.10.10.100 | YES | manual | up | up |
FastEthernet0/1 | unassigned | YES | unset administratively | down | down |
Vlan1 | unassigned | YES | unset administratively | down | down |
R1#
as we see the life is good for LAN 10.10.10.0/24
But i need to go and fix the other side; that is i need to go
R1#config t
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#int f0/1
R1(config-if)#ip address 20.20.20.100
% Incomplete command.
R1(config-if)#ip address 20.20.20.100 ?
A.B.C.D IP subnet mask
R1(config-if)#ip address 20.20.20.100 255.255.255.0
R1(config-if)#no shut
%LINK-5-CHANGED: Interface FastEthernet0/1, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/1, changed state to up
R1(config-if)#-
Now i will check other side by show ip int brief
R1#show ip int brief
Interface | IP-Address | OK? | Method | Status | Protocol |
FastEthernet0/0 | 10.10.10.100 | YES | manual | up | up |
FastEthernet0/1 | 20.20.20.100 | YES | manual | up | up |
Vlan1 | unassigned | YES | unset administratively | down | down |
Now I should be able ping from LAN 10.10.10.0/24 to LAN 20.20.20.4/24
Now I show you the use of ? with space and ? Without space
R1#cl
R1#cl
R1#cl?
clear clock
R1#clo
R1#clock ?
set Set the time and date
R1#clock set ?
hh:mm:ss Current Time
R1#clock set 15:15:10 ?
<1-31> Day of the month
MONTH Month of the year
R1#clock set 15:15:10 1 ?
MONTH Month of the year
R1#clock set 15:15:10 1 feburary ?
% Unrecognized command
R1#clock set 15:15:10 1 february ?
<1993-2035> Year
R1#clock set 15:15:10 1 february 2011 ?
<cr>
R1#clock set 15:15:10 1 february 2011
R1#
? Without space will finish your word
? With space will tell you what next command is
\
Ctrl+ A it moves all the way to beginning
ctrl+E it moves all the way to the end
ctrl+z= END it will take you back to the beginning
Any time you type on interface; it will overwrite it
R1#show ip int brief
Interface | IP-Address | OK? | Method | Status | Protocol |
FastEthernet0/0 | 50.50.50.100 | YES | manual | up | up |
FastEthernet0/1 | 20.20.20.100 | YES | manual | up | up |
Vlan1 | unassigned | YES | unset administratively | down | down |
As we see it overwrite it
Let’s put it back
R1#
R1#config t
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#int f0/0
R1(config-if)#ip add
R1(config-if)#ip address 10.10.10.100 255.255.255.0
R1(config-if)#
Now life is back to normal
R1#
R1#config t
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#int f0/0
R1(config-if)#ip add
R1(config-if)#ip address 10.10.10.100 255.255.255.0
R1(config-if)#
Here is a command that you must know
R1#show run
R1#show running-config
Building configuration…
Current configuration : 474 bytes
!
version 12.4
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname R1
!
!
!
!
!
!
interface FastEthernet0/0
ip address 10.10.10.100 255.255.255.0
duplex auto
speed auto
!
interface FastEthernet0/1
ip address 20.20.20.100 255.255.255.0
duplex auto
speed auto
!
interface Vlan1
no ip address
shutdown
!
ip classless
!
!
line con 0
line vty 0 4
login
!
end
To save your work on router
R1#copy run
R1#copy running-config st
R1#copy running-config startup-config
Destination filename [startup-config]?
Building configuration…
[OK]R1#
Now I will talk about the banner
R1#config t
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#ban
R1(config)#banner ?
login Set login banner
motd Set Message of the Day banner
R1(config)#banner motd
R1(config)#banner motd ?
LINE c banner-text c, where ‘c’ is a delimiting character
R1(config)#banner motd #Welcome to hame router#
R1(config)#
Lets check it ( Just Type Exit and then you will see the Banner)
Here is a good command that will stop looking for DNS
If I type for example CCNA ; it will waste my time
R1#ccna
Translating “ccna”…domain server (255.255.255.255)
To fix it do as follow
R1#config t
Enter configuration commands, one per line. End with CNTL/Z.
R1(config)#no ip domain-loo
R1(config)#no ip domain-lookup
R1(config)#^Z
R1#
%SYS-5-CONFIG_I: Configured from console by console
Now we see it did not waste my time when I type CCNA
R1#ccna
Translating “ccna”
% Unknown command or computer name, or unable to find computer address
Let’s check the state of the interfaces
R1#show ip interface brief
Interface | IP-Address | OK? | Method | Status | Protocol |
FastEthernet0/0 | 10.10.10.100 | YES | manual | up | up |
FastEthernet0/1 | 20.20.20.100 | YES | manual | up | up |
Vlan1 | unassigned | YES | unset administratively | down | down |
——————-So the 10.10.10.0 network is on interface fa0/0 and 20.20.20.0 is on fa0/1
——————-Also both links are int the up up state, which means they are operational
——————-Now we take a look at the routing table
R1#sh ip route
Codes: C – connected, S – static, I – IGRP, R – RIP, M – mobile, B – BGPD – EIGRP, EX – EIGRP external, O – OSPF, IA – OSPF inter areaN1 – OSPF NSSA external type 1, N2 – OSPF NSSA external type 2E1 – OSPF external type 1, E2 – OSPF external type 2, E – EGPi – IS-IS, L1 – IS-IS level-1, L2 – IS-IS level-2, ia – IS-IS inter area* – candidate default, U – per-user static route, o – ODR
P – periodic downloaded static route
Gateway of last resort is not set
10.0.0.0/24 is subnetted, 1 subnets
C 10.10.10.0 is directly connected, FastEthernet0/0
20.0.0.0/24 is subnetted, 1 subnets
C 20.20.20.0 is directly connected, FastEthernet0/1
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