Friday 24 February 2012

Different types of routes

In INTT, there are 5 types of routes
1) Connected routes
2) Static routes
3) Dynamic routes
4) Summary routes
5) Default routes

1) Connected routes are routes which are automatically created in the routing table upon entering the following commands to configure the interfaces

conf t
int fax/x or sx/x/x
ip address <host address> <subnet mask>
no shut

As long as the interfaces are configured in the router and are shown to be up and running, the router will assume that the interfaces belong to active subnets which are directly connected and thus, they create connected routes to them. Connected routes have a AD of 0 which is the highest in terms of trustworthiness in Cisco routers.

2) Static routes are routes which are created manually by operators. It is often denoted in the format as shown

ip route <destination network address> <subnet mask> <exit interface/next hop address>

In Newton's third law of motion where action and reaction are equal and opposite, we can infer that for every static path we create, there should be a reverse path. It is because most devices exchange requests and responses and there is a need for bi-directional paths. In choosing whether to use exit interfaces or next hop addresses, there are a few points to note. Firstly, static routes based on exit interfaces have faster lookup than next hop addresses. However, exit interfaces are more useful for serial point to point connections where there is only one device at each end. For ethernet networks, it is better to use next hop addresses to prevent flooding. Static routes AD is 1, which is less trustworthy than connected routes

3) Dynamic routes are routes created by the routers automatically. They do it by activating dynamic routing protocols. These protocols help the routers to advertise their directly connected networks to other routers using routing updates. They also calculate the best paths from these routing updates and place them inside the routing table. For RIP, the commands are as follows

router rip
network <directly connected network #1>
network <directly connected network #2>

For INTT, we learning about RIPv1 which is classful routing protocols and RIPv2, OSPF, EIGRP which are classless routing protocols. Classful routing protocols advertise their network addresses only while classless routing protocols advertise their network addresses and subnet masks. More details will be covered in my classes later on.

3) Summary routes are routes which combine various routes into a single route. This reduces the size of the routing table and makes routing faster. The tradeoff is that accurarcy of routing will be compromised as unwanted ip addresses get forwarded instead of dropped while using summarization.

4) Default routes are routes of the last resort. When the packets have no matching routing entries, the default route is used to forward the packets. Once a default route is created, no packets will be dropped by the router. All packets with unknown destinations will be forward through s0/0/0, in the case below.

ip route 0.0.0.0 0.0.0.0 s0/0/0

In case of a stub router, default routes can be used to summarized all the routes into one route.

Chapter 4 instructor slides uploaded

Here is the keypoint slides for chapter 4.

http://dl.dropbox.com/u/55776142/Chapter%204_Keypoint.pdf

Chapter 4 learning materials uploaded

Hello ! The presentation slides for Chapter 4 are as follows:

Summary Slides (Beginner)
http://dl.dropbox.com/u/55776142/CCNA2_Chp4_Dist_Vector_V1.ppt
Slightly Detailed Slides (Intermediate)
http://dl.dropbox.com/u/55776142/Expl_Rtr_chapter_04_DV.ppt
Detailed Slides (Advanced)
http://ibizzone.ite.edu.sg/elearning/file.php/38/Internetworking/Exp_2-Ch_4-Distance-Vector_revised.pdf
Quiz
http://ibizzone.ite.edu.sg/elearning/mod/quiz/view.php?id=3043

Follow your skill level and go through the slides. If you feel comfortable, go through the higher level slides as well and finally, attempt the quiz.

Thursday 23 February 2012

Convergence Test

http://dl.dropbox.com/u/55776142/RIP%20Set%20C_Solution.pkt

Remove the 192.168.2.0 subnet from the network and observe how convergence takes place.

You can pick any router and execute the following commands - display ip route, debug ip rip.

Monday 20 February 2012

VLSM Exercises

Please try out these exercises which I have downloaded from the Internet. :)

http://dl.dropbox.com/u/55776142/VLSM_Exercises.doc

I will go through them probably on Wednesday or Friday.

Good job, everyone ! Here are the solutions. Seems like most students can complete the questions within an hour.

http://dl.dropbox.com/u/55776142/VLSM_Exercises_Solutions.doc

Sunday 19 February 2012

Subnetting and supernetting questions and answers

Given 172.18.0.0/16, divide the class B major network into

1) 2 equal subnets and list all the network addresses/new subnet mask

    Answer: 172.18.0.0/17 and 172.18.128.0/17

2) 4 equal subnets and list all the network addresses/new subnet mask

    Answer: 172.18.0.0/18, 172.18.64.0/18, 172.18.128.0/18, 172.18.192.0/18

3) 8 equal subnets and list all the network addresses/new subnet mask

   Answer: 172.18.0.0/19, 172.18.32.0/19, 172.18.64.0/19, 172.18.96.0/19, 172.18.128.0/19, 172.18.160.0/19, 172.18.192.0/19, 172.18.224.0/19

   Note: Every additional bit you use for subnetting will cause the number of subnets to double and the  number of hosts per subnet to halve.

Given the subnet address 172.18.64.0/19 and divide further into

4) 2 equal subnets and list all the network addresses/new subnet mask
   
    Answer: 172.18.64.0/20 and 172.18.80.0/20

    Note: You can divide a chosen subnet (not restricted to major classful networks only) to obtain more smaller subnets.

5) Determine 192.168.1.0/24's number of subnets and hosts supported

    Answer: 1 subnet and 254 hosts per subnet

6) Determine 192.168.1.0/25's number of subnets and hosts supported

    Answer: 2 subnets and 126 hosts per subnet

7) Determine 192.168.1.0/26's number of subnets and hosts supported

    Answer: 4 subnets and 62 hosts per subnet

    Note: The more subnets you have, the more network addresses and broadcast addresses you need to reserve from the original classful major network.

8) Summarize the following into 1 single summary route
192.168.0.0/30
192.168.0.4/30
192.168.0.8/30
192.168.0.16/29
192.168.4.0/30
192.168.5.0/30
192.168.6.0/30
192.168.7.0/29

Answer: 192.168.0.0/21

9) Summarize the following into 1 single summary route
192.168.68.0/24
192.168.96.0/24
192.168.80.0/24

Answer: 192.168.64.0/18

Note: Summary routes make the routing table smaller and the lookup faster.

Chapter 6 instructor slides uploaded

This slides covers the keypoints of chapter 6.
http://dl.dropbox.com/u/55776142/Chapter%206_Keypoint.pdf

Please refer to the 3 sets of slides for more information.

Chapter 6 learning materials uploaded

Hello ! The presentation slides for Chapter 6 are as follows:

Summary Slides (Beginner)
http://dl.dropbox.com/u/55776142/CCNA2_Chp6_VLSM_CIDR_V1.ppt
Slightly Detailed Slides (Intermediate)
http://dl.dropbox.com/u/55776142/Expl_Rtr_chapter_06_VLSM_CIDR.ppt
Detailed Slides (Advanced)
http://ibizzone.ite.edu.sg/elearning/file.php/38/Internetworking/Exp_2-Ch_6-VLSM-CIDR.pdf
Quiz
http://ibizzone.ite.edu.sg/elearning/mod/quiz/view.php?id=3152

Follow your skill level and go through the slides. If you feel comfortable, go through the higher level slides as well and finally, attempt the quiz.

Friday 10 February 2012

Instructor slides uploaded

http://dl.dropbox.com/u/55776142/Chapter%205_Keypoint.pdf

These slides cover the main points of chapter 5 only. Please refer to the 3 sets of detailed slides for more information.
Hello ! The presentation slides for Chapter 5 are as follows:

Summary Slides (Beginner)
http://dl.dropbox.com/u/55776142/Exploration-Routing-Chapter-05.ppt
Slightly Detailed Slides (Intermediate)
http://dl.dropbox.com/u/55776142/Expl_Rtr_chapter_05_RIPv1.ppt
Detailed Slides (Advanced)
http://ibizzone.ite.edu.sg/elearning/mod/resource/view.php?id=3042
Quiz
http://ibizzone.ite.edu.sg/elearning/mod/quiz/view.php?id=3043

Follow your skill level and go through the slides. If you feel comfortable, go through the higher level slides as well and finally, attempt the quiz.

Thursday 2 February 2012

Static route test next week

There will be a static route test next Wednesday.

Special assignment solution

HQ Router

Router>sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
       i - 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
     192.168.9.0/24 is variably subnetted, 5 subnets, 2 masks
S       192.168.9.0/26 is directly connected, Serial0/0/1
S       192.168.9.64/26 is directly connected, Serial0/0/0
C       192.168.9.128/27 is directly connected, Serial0/0/0
C       192.168.9.160/27 is directly connected, Serial0/0/1
C       192.168.9.192/27 is directly connected, FastEthernet0/1

Branch 1 Router

Router>sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
       i - 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 0.0.0.0 to network 0.0.0.0
     192.168.9.0/27 is subnetted, 3 subnets
C       192.168.9.64 is directly connected, FastEthernet0/0
C       192.168.9.96 is directly connected, FastEthernet0/1
C       192.168.9.128 is directly connected, Serial0/0/0
S*   0.0.0.0/0 is directly connected, Serial0/0/0

Branch 2 Router

Router>sh ip route
Codes: C - connected, S - static, I - IGRP, 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, E - EGP
       i - 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 0.0.0.0 to network 0.0.0.0
     192.168.9.0/27 is subnetted, 3 subnets
C       192.168.9.0 is directly connected, FastEthernet0/1
C       192.168.9.32 is directly connected, FastEthernet0/0
C       192.168.9.160 is directly connected, Serial0/0/1
S*   0.0.0.0/0 is directly connected, Serial0/0/1

Wednesday 1 February 2012

You are welcome to post on the blog

Dear readers,

If you have any questions, you are welcome to post on the blog. I will try to answer within 24 hours.

Lab 3.5.2 submission

The following people has submitted their lab exercise

1) Zhihao
2) Eddy
3) Steven
4) Glenn
5) Joel
6) Micky
7) Huixiang
8) Junhui
9) Boon Wei
10) Kelvin

The rest of the class can submit by this Thursday :) It is okay to try and fail along the way, at least you learn something out of it. It beats not trying at all.