Hướng dẫn sử dụng GNS3

[thepdatoi87]

hinh nhu la vay

[thepdatoi87]

ah dung rui, no khong cau hinh duoc Switch

[tranmyphuc]

Become a CCIE with Simulator

Update: use GNS3. It even provides one installation file that contains all the packages (dynamips, dynagen, winpcap etc). Please RTFM.

Several months ago I wrote 'How to Become a CCIE', a step-by-step for wanna-be-CCIE out there based on my own experience passing two lab exams. In point no. 3 I mentioned that it's compulsory to have a home lab to be able to practice anytime.

How if we can save some money by not buying the equipment but using simulator instead? Thanks to Christophe Fillot, the author of Dynamips - Cisco 7200 Simulator, now it's possible to have a full CCIE lab in our PC.

The idea of this simulator is to emulate Cisco 7200 environment with MIPS processor in normal PC, so we can boot the genuine IOS for Cisco 7200 with 12.2 and 12.4 version. It can simulate various type of network modules such as PA-4T or PA-TE-FX to provide enough serial and ethernet interfaces. The simulator offers virtual ATM, FR and ethernet switch too. If we can simulate 8-9 routers, with ATM, FR and ethernet switch, and put proper interconnection between those routers..voila! we have a complete CCIE lab!

Actually this simulator has been around for quite some time. But when the first time I used this simulator, I faced so many minor issues that almost made me stop thinking about the idea to simulate CCIE lab. Before I found Dynagen, the front end interface for Dynamips, I had to map the port manually between interface in one router to another interface in another router to provide interconnectivity between them. That's because each interface in this virtual router consumes 1 UDP port. So if we want to connect one router to another router with serial connection, we need to map udp port that represents the serial interface in the first router, to the udp port that represents the serial interface in the second router.

The beauty of this is: we can connect virtual routers in one PC to another virtual routers in diferent PC through normal TCP/IP connection.
But if you have to do the mapping manually for let's say 8-9 routers..hmm, it's better to do something else with our life.

So I like to share the step-by-step how to setup CCIE lab in the PC quickly, so you can join me and all my friends who already started pursuing CCIE in this new and cheap way :)

1. You need a good PC for this simulator.
I bought a new PC for this purpose. It's a Shuttle XPC SD36G5 with Intel Dual Core 3.2 GHz and 2 GB DDR memory. Small but powerful.

With Windows OS I can simulate up to 11 routers. With Linux OS in the same machine I can simulate more than 15 routers. I read it somewhere that it's because the limitation in Windows for one process, such as this Dynamips, can take only up to 2 GB memory. While in Linux the limit for one process is 3 GB. So if one virtual router uses 128 MB, multiple this number by number of routers plus additional memory usage by the process, it makes sense to have the process crashed when the number of routers reaches more than 10.

But fear not, there are so many ways to resolve this problem. Use Linux is one solution. Or just run Dynamips in two different processes.
Surely you don't have to compete with my PC. Any decent PC with lots of memory should be enough.

2. You need Cisco IOS for 7200 routers.
Don't ask me, please. I am not allowed to distribute any IOS image.
Just get it from your close friend who works in Cisco partner and can download this IOS for you.
Since IOS comes as compressed binary, we need to unzip it first and keep the .bin extension:
$unzip -p c7200-js-mz.122-25.S9.bin > image.bin

I use the enterprise feature with 12.2.29S version.

3. Download Dynagen and Dynamips.
If you want to use Windows, Dynagen in SourceForge has already provided a package with Dynamips included and all the scripts to make our life easier.

4. Find the idle-pc value to avoid 100% CPU utilization.
Without idle-pc feature, even 1 single virtual router can shoot our PC CPU to 100%. To find the idle-pc value is simple:
- run one router with Dynamips (not Dynagen)
use the same IOS, NPE and memory that you want to use for your lab. For example, I choose NPE-400 and 96 MB ram for each virtual router:
$./dynamips -t npe-400 -r 96 image.bin

- wait until the router completes the booting process and give you the prompt
- go the enable mode and save the configuration with write memory
- press “Ctrl-] + i” sequence key, and it should give you similar output like below after few seconds:
Please wait while gathering statistics...
Done. Suggested idling PC:
0x60693f8c
0x60693fec
0x60694000
0xffffffff80755900
Restart the emulator with "--idle-pc=0x60693f8c" (for example)

- exit the simulator, you can do this by reloading the router
- run dynamips again with -idle-pc option with one of the value that you got from previous step:
$./dynamips -t npe-400 -r 96 -idle-pc=0x60693f8c image.bin

- monitor your PC CPU utilization, if it's still low than you are set to continue. If you still get 100% CPU utilization, try different value for the idle-pc option.

5. Run Dynamips in Hipervisor mode
We need to tell Dynamips to run in hipervisor mode which is basically waiting for connection in TCP port 7200 (default) for next instruction from Dynagen.
In Windows, there is a script called 'dynamips-start.cmd' to do this.
$./dynamips.exe -H 7200

Cisco 7200 Simulation Platform (version 0.2.5-RC2-x86)
Copyright (c) 2005,2006 Christophe Fillot.

Hypervisor TCP control server started.
Shutdown in progress...
Shutdown completed.

6. Create the Dynagen config file
Dynagen is awesome. The configuration is a text file that very easy to understand. It comes with sample labs and a text file, all_config_options, that explains all available options.
To practice IE Mentor and IP Expert CCIE Service Provider workbook, this is how I built my dynagen config file:

#I want to boot my routers manually
autostart = false

#I have the Dynamips in the same PC I run this Dynagen
[localhost]

#This is where I specify the location of IOS and options for NPE, RAM and idle-pc value
image = /home/himawan/IOS/c7200-js-mz.122-25.S9.bin
npe = npe-400
ram = 96
idlepc = 0xffffffff8075374c

#Each router's name and connectivity information, only showing some of them here
[[router CE1]]
f0/0 = CoreSW 1

[[router CE2]]
f0/0 = CoreSW 2

[[router PE1]]
f0/0 = CoreSW 10
f1/0 = CoreSW 11
a3/0 = A1 1
s2/0 = ASBR1 s1/2

[[router ASBR1]]
f0/0 = CoreSW 15
s1/0 = ASBR2 s1/0
s1/1 = ASBR2 s1/1

[[router ASBR2]]
f0/0 = CoreSW 16

#section for virtual ATM and ethernet switch, only showing few ports here
[[ETHSW CoreSW]]
1 = access 13
2 = access 23
3 = dot1q 1

[[ATMSW A1]]
1:1:100 = 2:1:100


As you can see the configuration file of Dynagen is very easy and straight forward. We can build as many routers as we want and put the interconnectivity information under each router. The good thing about Dynagen, we don't even need to specify which network module want to load, it will figure it out automatically.
For example, when I ASBR1 s1/0 is connected ASBR2 s1/0 interface, Dynagen will load PA-8T modules to those routers when I boot them. And one more thing, since I have specified it under ASBR1, under ASBR2 I don't need to specify that s1/0 needs to connect to ASBR1, Dynagen will take care of it automatically.

Under the virtual switch, we can assign either VLAN or dot1q trunk to the port. And for ATM switch, we can assign the value for VPI/VCI easily. Awesome, eh?

7. Execute Dynagen
Once you finish with the configuration, just make this file as executable in Linux or run Dynagen to use this configuration file:
C:\Program Files\Dynamips>dynagen.exe iementor.net

Reading configuration file...
Network successfully started

Dynamips management console
=> list
Name Type State Server Console
CE1 c7200 stopped localhost 2000
CE2 c7200 stopped localhost 2001
CE3 c7200 stopped localhost 2002

8. Start the routers, offcourse, and start playing with it!
=> start CE1
100-C7200 'CE1' started

If you don't put the Dynamips process in the background, you should see something like this:
CPU0: carved JIT exec zone of 16 Mb into 512 pages of 32 Kb.
C7200 instance 'CE1' (id 0):
VM Status : 0
RAM size : 96 Mb
IOMEM size : 0 Mb
NVRAM size : 128 Kb
NPE model : npe-400
Midplane : vxr
IOS image : c7200-js-mz.122-25.S9.bin

Loading ELF file 'c7200-js-mz.122-25.S9.bin'...
ELF entry point: 0x80008000

C7200 'CE1': starting simulation (CPU0 PC=0xffffffffbfc00000), JIT enabled.

You can even see the booting process if you want, by connecting to the console port which is starting from TCP port 2000 by default:
=> telnet CE1
or
telnet 127.0.0.1 2000

Now you have your lab ready, what are you waiting for?

Two more additional steps:
9. Googling or RTFM when you have problems
Read Chris's blog, check the FAQ, read the Dynagen tutorial, googling.. don't be lazy!

10. Simulating remote lab
I have a good PC at home but I have already got used to my IBM Thinkpad keyboard to practice CCIE lab. So what I did to simulate remote lab is:
- start Dynamips in Hipervisor mode in my home PC
- start Dynagen from my notebook, with modification in the config file, instead of [localhost] I specified [homePC_IP_address]
- once I connect to Dynamips, I start any routers that I like
- create shortcuts in my notebook Windows desktop such as CE1, CE2, ASBR1, R1, R2 and so on which is basically telneting to my home PC in respectable TCP ports
CE1.cmd file: start "CE1" telnet 127.0.0.1 2000
CE2.cmd file: start "CE2" telnet 127.0.0.1 2001
and so on

Now I just need to click CE1 shortcut to connect to CE1, CE2 to connect to CE2 and so on. It gives me the same feeling like when I had my CCIE lab in Brussels.


One thing to remember: this simulator can only simulate routers with ATM, frame-relay and virtual switch. It means if you are planning to go to CCIE lab other than R&S and Service Provider, you still need to buy some equipments such as Firewall for Security track or router with E1 interface for Voice track.
And also if you have less experience with Cisco IOS behaviour, when you face some issues in your lab you may not be able to distinguish the cause of the problem whether it's because of wrong configuration or Dynamips bugs or IOS bugs or lack of faith.

I may still require to rent a rack for some equipment that can't be simulated just like Cisco 3550. But the amount of time required in renting should be reduced significantly with this simulator.
So practice with simulator at home, and rent a rack several days before the exam.
It sounds like a good plan.

My only challenge now is that my PC is so powerful for gaming, especially after I added NVidia GeForce 6800XT 512Mb PCI Express graphic card. I can play The Battle for Middle Earth, Star Wars Empire at War, Ghost Recon Advance War Fighter and my most favorit game for whole time: Battle Field 2 with highest quality.

So now my CCIE SP plan has to compete with Snowboarding and Battle Field. What a tough life!

From : http://brokenpipes.blogspot.com/2006...simulator.html

Have fun.

[tranmyphuc]

Should I use emulator like dynamips or buy real lab?
Well, it depends. Dynamips is an emulator that somehow “tricks” the real IOS image so it will boot and run on standard PC. So far it can run IOS for 7200 routers, 3600, 3700 and 2600 series. So if you need to practice features outside those IOS, then you can’t do it with dynamips and must go with real lab.
What does exactly dynamips lack of?
Performance, even it doesn’t matter for CCIE practice lab, features that must be run in hardware such as certain QoS, and all the features outside the supported IOS for example L2 and switching features from a normal 3550 or 3560 switch. And we need to be aware that if there is any issue, we need to be able to identify if the issue is from wrong config, IOS bugs, or bug from the dynamips itself. With real lab, it’s just wrong config and IOS bugs.

Which CCIE track do you think can be done with emulator only?
For Service Provider track, you can practice almost 100% of the topic. The focus of the lab is on SP infrastructure so personally I don’t think you need to spend much time to practice L2 switch features. For Routing & Switching I think dynamips can still be used to cover almost 90%. Despite it has support Ethernet module but it still can’t be used to test real L2 switch features such as VTP and STP. But all L3 features from 3550/3560 switch can be tested or will have the same behavior just as if we use normal router. For Security track the emulator can be used to test IOS FW, IOS IPS, VPN between routers and security features in routers (NAT, ACL, RTBH etc). But more than half of the features for this track require Firewall, VPN, IDS and Cisco Secure ACS. For the rest of tracks, I would say the emulator won’t help that much. Check the CCIE lab blueprint and CCIE lab equipments to give you the idea.
What would I miss from the real lab?
Using real lab we would be able to test all the features required in CCIE lab, real router with real performance, capable to test hardware-dependent features, ability to sell it back when we are done and last but not least, the noise I guess. I used to sleep next to my lab for months so sometime I feel that I can still hear the noise inside my head until now.
What would be your suggestion to cover the lacks from dynamips?
There are several options. You may invest and buy a complete real lab. The challenge to have real lab is we need to replicate as close as possible to the lab equipments. It means, it can be expensive. But the good thing is, if our lab is still in decent condition after we are done, we may be able to sell it again (to another CCIE candidates) without losing a penny at all. Another option is to rent an online rack. It has advantage since we can connect to it as long we have Internet and we don’t need to invest big pile of money in the beginning, but obviously the money won’t go back after we are done. The option that you may want to consider is using dynamips to practice and cover as many features as possible (such as R&S and Security) then go to online rack rental a couple of weeks before the exam. For track like security, you may want to invest in Firewall and VPN hardware, then connect them to dynamips. To practice IDS and for final preparation before taking the exam, you can use online rack for several days. List down all your options then make the pros and cons from each of them before you decide.
Do you know people who passed using dynamips only?
Yes, I know many people have passed CCIE lab using dynamips/emulator. In fact, for my third lab which is Service Provider track I practiced only using the emulator similar like dynamips. And no, I won’t tell you what it is nor I would discuss about it in this blog.
Do you think the people who passed using dynamips/emulator only are not real CCIE, since they never touch real routers?
No, there is no such thing. Passing CCIE lab just means you pass a lab exam. What makes a difference later on is your experience and expertise in real life. So someone may pass CCIE using only emulator and never touch the real routers, and he is still a CCIE. Later on he can gain experience and expertise with real routers. That’s what matter at the end of the day.
Will you teach me how to configure dynamips/other emulator?
No. RTFM. Googling.
Will you send IOS for me to use in emulator?
No. It’s actually illegal to run IOS software without license, but for practice lab at home I don’t think Cisco would bother chasing you. But I won’t send any IOS.
How to find info if I have issue with dynamips?
Again, RTFM and googling. And you should join the forum and become active member to discuss it. As I mentioned above, if there is any issue when you practice CCIE with emulator, it may come from wrong config, IOS bugs or bug in dynamips. So by becoming active member in the forum, and if you are willing to use the emulator heavily, you can contribute if you think the issue is from dynamips itself. Help the community to maintain and develop this wonderful emulator.
So should I use emulator or buy real lab to practice CCIE?
????!@#$%^&* Scroll up and read again from beginning.


From : http://www.ciscobible.net/archives/216


Have fun.

[VoT]

Các bạn cho mình hỏi chút với, về GNS3 trong Leopard. Bình thường mình dùng GNS3 trên window hay linux đều có chức năng sniff gói trên topo ảo, nhưng sang Leopard, GNS3 thông báo không tìm thấy Wireshark , mặc dù mình có cài đặt wireshark bình thường rồi
Rất mong được trợ giúp

[quynhbk]

Mọi người giúp mình trường hợp này với: GNS3 ko thể giao tiếp với mạng thực tế trong Window Vista. Khi chọn Cloud thì nó ko thể hiện ra vị trí Net Card vì vậy không the chọn được card.

Help help me!!!!!!!!

[quynhbk]

Đã làm cho giao tiếp với mạng thực.
Thanks cả nhà. Vào http://7200emu.hacki.at/ có hướng dẫn đầy đủ hết.

Thanks all,

[dyland]

GNS3 co su dung de mo phong cho Switch duoc khong ?va cach lam nhu the nao ?cac hinh anh huong dan su dung GNS3 ko con nua ???

[dyland]

mình đang mò mẫm tìm cách sử dụng switch trên GNS3 nhưng thật là khó khăn ,packet tracert thi chỉ hỗ trợ một số command,hi vọng là ai đã từng dùng GNS3 để mô phỏng thì có thể chỉ cho mình step by step với nhé !

[itdongnai]

cài phần mềm này có thể thay thế được dynagen đúng ko?mà lại là giao diện đồ hoạ dễ dùng nữa.Mong các pác chỉ giáo thêm

[sem_it]

khi em telnet bằng SecureCRT thì báo lỗi

các anh giúp em với

[sem_it]

cảm ơn bạn đã trả lời bài cho mình. Nhưng mình đã làm theo mà vẫn ko dc. Mình đang sử dụng win7 64bit.

[redwind]

Các bạn cho mình hỏi:Sao mình thử làm theo hướng dẫn, kết nối GNS3 ra mạng thật không được nhỉ? Khi mình ngắt hết kết nối mạng ngoài, chỉ sử dụng cổng Loopback thì Router có thể làm việc với máy tính. Khi mình kết nối máy tính với mạng thì thử mọi cách Router đều không thể Ping ra mạng ngoài, thậm chí không thể Ping tới máy tính được nữa (mình đã làm với cả Mạng Wire và Wireless đều không được, Firewall trên máy đã tắt hết). Mọi người có thể trả lời giúp được không? Thanks.

[ntaitiep]

hic! em moi tìm hiểu về GNS3 mà vào đọc lướt xong 9 trang choáng hết cả đầu,1 người chưa biết gì về mạng như em chắc còn phải học nhìu! hix thank mấy anh bên rum vnpro nhìu lắm!

[leetoo]

các a cho e hỏi câu lệnh gán cổng cho vlan là gì ? mà sao e đánh hoài mà cũng ko đc