Static Route

In this post I will create a static route to route traffic from R0 (192.168.1.0/30 network) to R2 (192.168.1.4/30 network).


To begin with I check my routing table on R0.


R0#sh ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, 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

192.168.1.0/30 is subnetted, 1 subnets
C 192.168.1.0 is directly connected, Serial1/0


Currently I can only see directly connected interfaces. Without any static routes or routing protocols traffic from one network cannot reach the other.


R0#ping 192.168.1.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/11/24 ms

R0#ping 192.168.1.5

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.5, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)


I can ping the R1 interface on my network but not the interface on the other network. This is because R0 does not know where 192.168.1.5 is. By creating a static route I tell R0 which interface to send packets out of.


R0(config)#ip route 192.168.1.4 255.255.255.252 192.168.1.3 
R0(config)#end 


Now when I examine the route table I can see the static route I have created.


R0#sh ip route
Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, 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

192.168.1.0/30 is subnetted, 2 subnets
C 192.168.1.0 is directly connected, Serial1/0
S 192.168.1.4 [1/0] via 192.168.1.3


Now If I attempt to ping the ethernet interface on R1 I get a response.


R0#ping 192.168.1.5

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.5, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 4/6/8 ms


So what about R2?


R0#ping 192.168.1.6

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.6, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)


Well R2 is receiving the ICMP ping packets but it doesn't know how to get them back to me. By going to R2 and giving it a route to get back it will know which direction to send packets back.


R2#conf t
Enter configuration commands, one per line. End with CNTL/Z.
R2(config)#ip route 192.168.1.0 255.255.255.252 192.168.1.4


Because R1 know which networks it is directly connect to it happily passes the packets to the correct interface.


R1#sh ip route connected 
192.168.1.0/30 is subnetted, 2 subnets
C 192.168.1.0 is directly connected, Serial0/0
C 192.168.1.4 is directly connected, Ethernet1/0


Attempting to ping R2 from R0 now produces the desired result.

R0#ping 192.168.1.6

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.1.6, timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 4/12/24 ms

CCNA

Welcome to the CCNA Introduction to Networks course. The goal of this course is to introduce you to fundamental networking concepts and technologies. These online course materials will assist you in developing the skills necessary to plan and implement small networks across a range of applications. The specific skills covered in each chapter are described at the start of each chapter.

You can use your smart phone, tablet, laptop, or desktop to access your course, participate in discussions with your instructor, view your grades, read or review text, and practice using interactive media. However, some media are complex and must be viewed on a PC, as well as Packet Tracer activities, quizzes, and exams.