IP Routing

1. Chapter 2
IP Routing
CISCO Networking II
1
By Chhay Buntha

2. Introduction
Chapter2
2
By Chhay Buntha
ត ើ data ត្វើដំត ើរពីកន្លែងមួយ តៅកាល់កន្លែងមួយត ៀ តាមប្រព័លធ Internet យ៉ាងដូចតមេច?

3. IP Routing
Chapter2
3
By Chhay Buntha
IP Routing គឺជាដំត ើរការកនុងការរញ្ជូល packets ពី network មួយ តៅកាល់ network មួយ
ត ៀ តោយតប្រើ routers។
A routing protocol គឺជា tool មួយប្ ូវបាលតប្រើប្បាស់តៅកនុង routers តដើម្បីន្សវងរកផ្ែូវត្វើ
ដំត ើរររស់ packets តៅកាល់ប្គរ់ networks ទំងអស់ លិងពិលិ ្យតមើលថាត ើ routing table
មាលប្គរ់ត ើយឬតៅ។

4. Routing Basic
Chapter2
4
By Chhay Buntha
តៅតពលន្ដល router បាលដឹងព័ ៌មាលអំពីប្គរ់ networks ត ើយ, routed protocol អាចត្វើ
ការរញ្ជូល packets តាមរយៈ network ន្ដលបាលភ្ជារ់។
Routing protocol គឺមិលស្គាល់ Host IP address ត , គឺស្គាល់ លិងត្វើការ ជាមួយន្ network
IP លិង ផ្ែូវណាន្ដលលអសប្មារ់រញ្ជូល packet តៅកាល់ network លីមួយៗ

5. ត ើ Router គួរដឹងអំពីអវីខ្លះ?
Chapter2
5
By Chhay Buntha
- Destination Address, សប្មារ់ static routing protocol
- Neighbor routers ន្ដលអាច ំនាក់ ំលងជាមួយ networks តផ្្េងត ៀ បាល
- ផ្ែូវន្ដលអាចឲ packets ត្វើដំត ើរតៅកាល់ប្គរ់ networks

6. Learn about remote networks
Chapter2
6
By Chhay Buntha
• From neighbor routers or from an administrator.
• The router then builds a routing table
• If a network is directly connected, then the router already knows how to get to it.

7. ប្រតេទ Routing Protocols
Chapter2
7
By Chhay Buntha
Static Routing Protocol Default Routing Protocol

8. Static Routing Protocol
Chapter2
8
By Chhay Buntha
Static Routing Protocol: គឺជា protocol មួយន្ដល ប្មូវឲ administrator រញ្ចូលលូវព័ ៌មាល
ពីប្គរ់ ីតាំង networks ទំងអស់តៅកនុង routing table តោយផ្ទាល។ ជាការលអប្រតសើរសប្មារ់
សុវ ថិភ្ជពររស់ network ។
Advantages:
- No overhead on router CPU.
- No bandwidth usage between links.
- Security (Only Administrator can add routers)

9. Static Routing Protocol
Chapter2
9
By Chhay Buntha
Disadvantages:
- Administrator must really understand internetwork and how each router is
connected.
- Not recommend for a large network.
- Administrator must update all routers.

10. Default Routing Protocol
Chapter2
10
By Chhay Buntha
- Default Routing Protocol: គឺជា protocol មួយន្ដល ប្មូវឲ administrator រញ្ចូលលូវ IP
network destination សប្មារ់ប្គរ់ network ទំងអស់តោយមិលបាលកំ ់តៅកាល់
network ជាក់លាក់ណាមួយ (0.0.0.0 0.0.0.0) លិង next hop ន្ដលអាចតៅដល់តោលតៅ
ន្ដល packets ចង់តៅ។
រញ្ជាក់ៈ Default Routing Protocol មួយតលេះអាចតប្រើបាលន្ តៅ តលើ Router ណាន្ដលមាល
WAN connection (interface) ន្ មួយ។

11. Dynamic Routing Protocol
Chapter2
11
By Chhay Buntha
Dynamic Routing Protocol: គឺជា protocol មួយន្ដល ប្មូវ ឲ administrator រញ្ចូល
ព័ ៌មាលអំពី network IDs ន្ដលបាលភ្ជារ់មក router ខ្ែួលឯងទំងអស់ តដើម្បី advertise ឲ
routers តផ្្េងត ៀ បាលដឹង, ត ើយវាត្វើការ advertise លូវតរៀងរាល់ 30sec or 90sec មេង,
ន្ដល ប្មូវឲមាលការតប្រើប្បាស់ bandwidth តៅតពល advertise មេងៗ។

12. Dynamic Routing Protocol
Chapter2
12
By Chhay Buntha
Advantages:
- Less work in maintaining the configuration when adding or remove networks.
- Protocol automatically reach to the topology changes.
- Less configuration and more scalable.
Disadvantages:
- Router resources are used
- More administrative knowledge is required for configurations.

13. Dynamic Routing Protocol
Chapter2
13
By Chhay Buntha
The dynamic routing protocols can be categorized on the basis of various
parameters. Dynamic routing protocols are classified into two protocols:
1. Distance Vector Routing Protocol: It uses simple algorithms that calculate
cumulative distance value between routers based on hop count.
Example:
- Routing Information Protocol (RIP)
- Interior Gateway Routing Protocol (IGRP)

14. Dynamic Routing Protocol
Chapter2
14
By Chhay Buntha
2. Link State Routing Protocols: It uses sophisticated algorithms that maintain a
complex database of internetwork topology.
Example:
- Enhanced Interior Gateway Routing Protocol (EIGRP)
- Open Shortest Path First (OSPF)

15. Routing Information Protocols (RIP) version 1
Chapter2
15
By Chhay Buntha
• RIP is a distance vector routing protocol.
• Metric: hop count
• Advertised routes with metric > 15 are unreachable.
• Route updates every 30 seconds.
• Support classful network
• Administrative Distance: 120
• RIP v1 is a classful routing protocol.
• So, a router either uses the subnet mask configured on a local interface, or
applies the default subnet mask.

16. Administrative Distance
Chapter2
16
By Chhay Buntha
• AD is the trustworthiness (or preference) of the route source.
• RIP AD is 120.

17. RIP v1 Configuration Scenario 1
Chapter2
17
By Chhay Buntha
• AD is the trustworthiness (or preference) of the route source.
• RIP AD is 120.
192.168.2.2/24
192.168.2.1/24

18. Enabling RIP: router rip
Chapter2
18
By Chhay Buntha
R2#config t
R2(config)#router ?
bgp Border Gateway Protocol (BGP)
eigrp Enhanced Interior Gateway Routing Protocol
(EIGRP)
isis ISO IS-IS
iso-igrp IGRP for OSI networks
lisp Locator/ID Separation Protocol
mobile Mobile routes
odr On Demand stub Routes
ospf Open Shortest Path First (OSPF)
ospfv3 OSPFv3
rip Routing Information Protocol (RIP)
R2(config)#router rip
R2(config-router)#

19. Specifying Networks
Chapter2
19
By Chhay Buntha
R1(config)#router rip
R1(config-router)#network 192.168.1.0
R1(config-router)#network 192.168.2.0
R2(config)#router rip
R2(config-router)#network 192.168.3.0
R2(config-router)#network 192.168.2.0
R2(config-router)#network 192.168.4.0
R3(config)#router rip
R3(config-router)#network 192.168.4.0
R3(config-router)#network 192.168.5.0

20. Verifying RIP: show ip route
Chapter2
20
By Chhay Buntha
R1#sh ip route
Codes: L - local, 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, H - NHRP, l - LISP
+ - replicated route, % - next hop override
Gateway of last resort is not set
192.168.1.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.1.0/24 is directly connected, FastEthernet0/0
L 192.168.1.1/32 is directly connected, FastEthernet0/0
192.168.2.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.2.0/24 is directly connected, FastEthernet0/1
L 192.168.2.1/32 is directly connected, FastEthernet0/1
R 192.168.3.0/24 [120/1] via 192.168.2.2, 00:00:19, FastEthernet0/1
R 192.168.4.0/24 [120/1] via 192.168.2.2, 00:00:19, FastEthernet0/1
R 192.168.5.0/24 [120/2] via 192.168.2.2, 00:00:19, FastEthernet0/1

21. Verifying RIP: show ip route
Chapter2
21
By Chhay Buntha
R2#sh ip route
Codes: L - local, 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, H - NHRP, l - LISP
+ - replicated route, % - next hop override
Gateway of last resort is not set
R 192.168.1.0/24 [120/1] via 192.168.2.1, 00:00:04, FastEthernet0/1
192.168.2.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.2.0/24 is directly connected, FastEthernet0/1
L 192.168.2.2/32 is directly connected, FastEthernet0/1
192.168.3.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.3.0/24 is directly connected, FastEthernet0/0
L 192.168.3.1/32 is directly connected, FastEthernet0/0
192.168.4.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.4.0/24 is directly connected, FastEthernet1/0
L 192.168.4.2/32 is directly connected, FastEthernet1/0
R 192.168.5.0/24 [120/1] via 192.168.4.1, 00:00:20, FastEthernet1/0
R2#

22. Verifying RIP: show ip route
Chapter2
22
By Chhay Buntha
R3#sh ip route
Codes: L - local, 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, H - NHRP, l - LISP
+ - replicated route, % - next hop override
Gateway of last resort is not set
R 192.168.1.0/24 [120/2] via 192.168.4.2, 00:00:11, FastEthernet1/0
R 192.168.2.0/24 [120/1] via 192.168.4.2, 00:00:11, FastEthernet1/0
R 192.168.3.0/24 [120/1] via 192.168.4.2, 00:00:11, FastEthernet1/0
192.168.4.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.4.0/24 is directly connected, FastEthernet1/0
L 192.168.4.1/32 is directly connected, FastEthernet1/0
192.168.5.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.5.0/24 is directly connected, FastEthernet0/0
L 192.168.5.1/32 is directly connected, FastEthernet0/0
R3#

23. Verifying RIP: show ip protocols
Chapter2
23
By Chhay Buntha
R2#sh ip protocols
*** IP Routing is NSF aware ***
Routing Protocol is "rip"
Outgoing update filter list for all interfaces is not set
Incoming update filter list for all interfaces is not set
Sending updates every 30 seconds, next due in 11 seconds
Invalid after 180 seconds, hold down 180, flushed after 240
Redistributing: rip
Default version control: send version 1, receive any version
Interface Send Recv Triggered RIP Key-chain
FastEthernet0/0 1 1 2
FastEthernet0/1 1 1 2
FastEthernet1/0 1 1 2
Automatic network summarization is in effect
Maximum path: 4
Routing for Networks:
192.168.2.0
192.168.3.0
192.168.4.0
Routing Information Sources:
Gateway Distance Last Update
192.168.2.1 120 00:00:13
192.168.4.1 120 00:00:26
Distance: (default is 120)

24. Routing Information Protocols (RIP) version 2
Chapter2
24
By Chhay Buntha
Difference between RIPv1 & RIPv2
• RIPv1
• A classful distance vector routing protocol
• Does not support discontiguous subnets
• Does not support VLSM
• Does not send subnet mask in routing update
• Routing updates are broadcast
• RIPv2
• A classless distance vector routing protocol that is an enhancement of
RIPv1’s features
• Next hop address is included in updates
• Routing updates are multicast
• The use of authentication is an option

25. Routing Information Protocols (RIP) version 2
Chapter2
25
By Chhay Buntha
Similarities between RIPv1 & RIPv2
• Use of timers to prevent routing loops
• Use of split horizon or split horizon with poison reverse
• Use of triggered updates
• Maximum hop count of 15

26. RIP v1 Limitations: Scenario 2
Chapter2
26
By Chhay Buntha
• 3 routers set up
• Routers 1 & 3 contain VLSM networks

27. RIP v1 Limitations: Scenario 2
Chapter2
27
By Chhay Buntha
• VLSM, Recall this is sub
netting the subnet
• Private IP addresses are
on LAN links
• Public IP addresses
are used on WAN
links
• Loopback interfaces
These are virtual

28. RIP v1 Limitations: Scenario 2
Chapter2
28
By Chhay Buntha
No CIDR Support
Classful routing protocols do not support CIDR routes that are summarized with a smaller
mask than the classful subnet mask

29. Verifying RIP1: show ip route
Chapter2
29
By Chhay Buntha
R2#sh ip route
Codes: L - local, 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, H - NHRP, l - LISP
+ - replicated route, % - next hop override
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 10.1.0.0/16 is directly connected, FastEthernet0/0
L 10.1.0.1/32 is directly connected, FastEthernet0/0
R 172.30.0.0/16 [120/1] via 209.165.200.233, 00:00:08, FastEthernet1/1
[120/1] via 209.165.200.229, 00:00:16, FastEthernet0/1
209.165.200.0/24 is variably subnetted, 4 subnets, 2 masks
C 209.165.200.228/30 is directly connected, FastEthernet0/1
L 209.165.200.230/32 is directly connected, FastEthernet0/1
C 209.165.200.232/30 is directly connected, FastEthernet1/1
L 209.165.200.234/32 is directly connected, FastEthernet1/1

30. Configuring RIPv2
Chapter2
30
By Chhay Buntha
• Enabling and Verifying RIPv2
• Configuring RIP on a Cisco router
• By default it is running RIPv1
• RIPv2 on a Cisco router
• Requires using the version 2 command
• RIPv2 ignores RIPv1 updates
• To verify RIPv2 is configured use the
• # show ip protocols

31. Verifying RIP2: show ip route
Chapter2
31
By Chhay Buntha
R2#sh ip route
Codes: L - local, 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, H - NHRP, l - LISP
+ - replicated route, % - next hop override
Gateway of last resort is not set
10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 10.1.0.0/16 is directly connected, FastEthernet0/0
L 10.1.0.1/32 is directly connected, FastEthernet0/0
172.30.0.0/16 is variably subnetted, 3 subnets, 2 masks
R 172.30.0.0/16 [120/1] via 209.165.200.233, 00:00:18, FastEthernet1/1
R 172.30.1.0/24 [120/1] via 209.165.200.229, 00:00:10, FastEthernet0/1
R 172.30.2.0/24 [120/1] via 209.165.200.229, 00:00:10, FastEthernet0/1
209.165.200.0/24 is variably subnetted, 4 subnets, 2 masks
C 209.165.200.228/30 is directly connected, FastEthernet0/1
L 209.165.200.230/32 is directly connected, FastEthernet0/1
C 209.165.200.232/30 is directly connected, FastEthernet1/1
L 209.165.200.234/32 is directly connected, FastEthernet1/1

32. Dynamic Routing Protocols
Chapter2
32
By Chhay Buntha
Networks within a given organization are grouped into Autonomous Systems (AS)
• An AS is a collection of Internet Protocol (IP) routing prefixes under the
control of a single administrative entity that present a common, clearly
defined routing policy to the Internet
• Interior Gateway Protocols (IGPs) are used to exchange routing information
within a given AS
• Exterior Gateway Protocols (EGPs) are used to exchange routing information
between routers bordering two networks (i.e. between two Autonomous
Systems)

33. Dynamic Routing Protocols
Chapter2
33
By Chhay Buntha

34. Interior Gateway Protocol (IGP)
Chapter2
34
By Chhay Buntha
Interior Gateway Protocols
• Used within an Autonomous System
• Distribute internal infrastructure prefixes only, not external routing information
• Examples –OSPF, IS-IS, RIP
IGPs are designed to route packets within an AS and rapidly adapt to network
failures
All IGPs function to identify the shortest cost path between two endpoints, typically
via summation of the metrics of all the individual links

35. External Interior Gateway Protocol (IGP)
Chapter2
35
By Chhay Buntha
• Interior Routing protocols operated within an Autonomous System.
• Collection of routers and networks under the same administration or routing
policy.
• Usually under single ownership, trust and administrative control.
Characteristics:
• Internal connectivity: All parts of an AS must remain connected, meaning that its
all routers must exchange routing information in order to maintain the
connectivity.
• A single routing protocol required to run in an AS, between all routers.

36. External Interior Gateway Protocol (EIGP)
Chapter2
36
By Chhay Buntha