Static routing occurs when you manually add routes in each
router's routing table. There are advantages and disadvantages to static
routing, but that's true for all routing processes.
Static routing has the following advantages:
·
There is no overhead on the router CPU.
·
There is no bandwidth usage between routers.
·
It adds security because the administrator can choose to allow routing
access to certain networks only.
Static routing has the following
disadvantages:
·
The administrator must really
understand the internetwork and how each router is connected in order to
configure routes correctly.
·
If a network is added to the
internetwork, the administrator has to add a route to it on all
routers—manually.
·
It's not possible in large networks
because maintaining it would be a full-time job in itself.
Command syntax for static
route:
ip
route [destination_network] [mask] [next-hop_address or
exit_interface][administrative_distance] [permanent]
ip route :The command
used to create the static route
Destination network: The network you're placing in the routing table
Mask The subnet mask being used on the network
Next-hop address:The address of the next-hop router that will
receive the packet and forward it to the remote network.
exit
interface Used in
place of the next-hop address if you want, and shows up as a directly connected
route.
administrative_distance By default, static routes have an
administrative distance of 1 (or even 0 if you use an exit interface instead of
a next-hop address).
permanent Keyword (Optional) Without the permanent keyword in a static route
statement, a static route will be removed if an interface goes down. Adding the
permanent keyword to a static route statement will keep the static routes in
the routing table even if the interface goes down and the directly connected networks
are removed.
Default Routing:
Default routing is used to send packets with a remote destination network not in the routing table to the next-hop router. You should only use default routing on stub networks—those with only one exit path out of the network.
How to configure Default routing on Cisco router :
Configuration:
PC0: IP address 10.0.0.2 Subnet mask 255.0.0.0 Default Gateway 10.0.0.1
PC0: IP address 30.0.0.2 Subnet mask 255.0.0.0 Default Gateway 30.0.0.1
1841 Router 0:
Continue with configuration dialog? [yes/no]: no
Press RETURN to get started!
Router>
Router>enable
Router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#hostname R1
R1(config)#banner motd # Unauthorized access is prohibited #
R1(config)#interface fastethernet 0/0
R1(config-if)#ip address 10.0.0.1 255.0.0.0
R1(config-if)#no shutdown
%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up
R1(config-if)#exit
R1(config)#
R1(config)#interface serial 0/0/0
R1(config-if)#ip address 20.0.0.1 255.0.0.0
R1(config-if)#clock rate 64000
R1(config-if)#bandwidth 64
R1(config-if)#no shutdown
%LINK-5-CHANGED: Interface Serial0/0/0, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0/0, changed state to up
R1(config-if)#exit
R1(config)#
R1(config)#ip route 30.0.0.0 255.0.0.0 20.0.0.2
R1(config)#
30.0.0.0 = destination network.
255.0.0.0 = subnet mask.
20.0.0.2 = next-hop address.
2621XMRouter1:
Router>enable
Router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#hostname R2
R2(config)#interface fastEthernet 0/0
R2(config-if)#ip address 30.0.0.1 255.0.0.0
R2(config-if)#no shutdown
%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up
R2(config-if)#exit
R2(config)#
R2(config)#interface serial 0/0
R2(config-if)#ip address 20.0.0.2 255.0.0.0
R2(config-if)#no shutdown
R2(config-if)#exit
R2(config)#ip route 10.0.0.0 255.0.0.0 20.0.0.1
R2(config)#
10.0.0.0 = Destination network
255.0.0.0 =Subnet mask
20.0.0.1=Next hop IP
We will use four different series router
A static route is a manually configured route
on your router. Static routes are typically used in smaller networks and when
few networks or subnets exist, or with WAN links that have little available
bandwidth. With a network that has hundreds of routes, static routes are not
scalable, since you would have to configure each route and any redundant paths
for that route on each router.
|
1841 Series
Router0 (R1)
|
|
|
FastEthernet0/0
|
Serial0/1/0
|
|
IP address
|
10.0.0.1
|
20.0.0.1
|
|
Connected
With
|
Pc0
|
R2 on Serial
1/0
|
|
2620XM
Series Router1 (R2)
|
|
|
FastEthernet0/0
|
Serial1/0
|
|
|
IP address
|
30.0.0.1
|
20.0.0.2
|
|
|
Connected
With
|
R3 on
FastEthernet0/0
|
R1 on Serial
0/1/0
|
|
|
2621XM
Series Router0 (R3)
|
|
|
|
FastEthernet0/0
|
Serial1/0
|
|
IP address
|
30.0.0.2
|
40.0.0.1
|
|
Connected
With
|
FastEthernet0/0
|
R4 on Serial
1/0
|
|
|
|
|
|
2811 Series
Router0 (R4)
|
|
|
FastEthernet0/0
|
Serial1/0
|
|
|
IP address
|
50.0.0.1
|
40.0.0.2
|
|
|
Connected
With
|
Pc1
|
R3 on Serial
1/0
|
|
(1841Router0)
Hostname R1:
Router>enable
Router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#hostname R1
R1(config)#interface fastethernet 0/0
R1(config-if)#ip address 10.0.0.1 255.0.0.0
R1(config-if)#no shutdown
%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)#exit
R1(config)#interface serial 0/0/0
R1(config-if)#ip address 20.0.0.1 255.0.0.0
R1(config-if)#clock rate 64000
R1(config-if)#bandwidth 64
R1(config-if)#no shutdown
%LINK-5-CHANGED: Interface Serial0/0/0, changed state to down
R1(config-if)#exit
%LINK-5-CHANGED: Interface Serial0/0/0, changed state to up
R1(config)#ip route 30.0.0.0 255.0.0.0 20.0.0.2
R1(config)#ip route 40.0.0.0 255.0.0.0 20.0.0.2
R1(config)#ip route 50.0.0.0 255.0.0.0 20.0.0.2
(2620XM-Router1)
Hostname R2:
Router>enable
Router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#hostname R2
R2(config)#interface serial 0/0
R2(config-if)#ip address 20.0.0.2 255.0.0.0
R2(config-if)#no shutdown
%LINK-5-CHANGED: Interface Serial0/0, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to up
R2(config-if)#exit
R2(config)#interface fastethernet 0/0
R2(config-if)#ip address 30.0.0.1 255.0.0.0
R2(config-if)#no shutdown
%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up
R2(config-if)#exit
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up
R2(config)#ip route 10.0.0.0 255.0.0.0 20.0.0.1
R2(config)#ip route 40.0.0.0 255.0.0.0 30.0.0.2
R2(config)#ip route 50.0.0.0 255.0.0.0 30.0.0.2
(2620XM-Router2)Hostname
R3:
Router>enable
Router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#hostname R3
R3(config)#interface fastethernet 0/0
R3(config-if)#ip address 30.0.0.2 255.0.0.0
R3(config-if)#no shutdown
%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up
R3(config-if)#interface serial 0/0
R3(config-if)#ip address 40.0.0.1 255.0.0.0
R3(config-if)#clock rate 64000
R3(config-if)#bandwidth 64
R3(config-if)#no shutdown
%LINK-5-CHANGED: Interface Serial0/0, changed state to down
R3(config-if)#exit
%LINK-5-CHANGED: Interface Serial0/0, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to up
R3(config)#ip route 10.0.0.0 255.0.0.0 30.0.0.1
R3(config)#ip route 20.0.0.0 255.0.0.0 30.0.0.1
R3(config)#ip route 50.0.0.0 255.0.0.0 40.0.0.2
(2811Router3)
Hostname R4:
Router>enable
Router#configure terminal
Enter configuration commands, one per line. End with CNTL/Z.
Router(config)#interface serial 0/0/0
Router(config-if)#ip address 40.0.0.2 255.0.0.0
Router(config-if)#no shutdown
%LINK-5-CHANGED: Interface Serial0/0/0, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0/0, changed state to up
Router(config-if)#exit
Router(config)#interface fastethernet 0/0
Router(config-if)#ip address 50.0.0.1 255.0.0.0
Router(config-if)#no shutdown
%LINK-5-CHANGED: Interface FastEthernet0/0, changed state to up
%LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/0, changed state to up
Router(config-if)#exit
Router(config)#ip route 10.0.0.0 255.0.0.0 40.0.0.1
Router(config)#ip route 20.0.0.0 255.0.0.0 40.0.0.1
Router(config)#ip route 30.0.0.0 255.0.0.0 40.0.0.1
PC-1:
PC>ipconfig
IP Address......................: 10.0.0.2
Subnet Mask.....................: 255.0.0.0
Default Gateway.................: 10.0.0.1
PC-2:
PC>ipconfig
IP Address......................: 50.0.0.2
Subnet Mask.....................: 255.0.0.0
Default Gateway.................: 50.0.0.1
