Server Fault is a question and answer site for system and network administrators. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I am looking for a free virtual lab where I can test various Cisco Configurations. I currently work for a company that does not have many Cisco boxes, or routers/switches of any vendor in lab, which forces me to plan very well and make changes to operational network without prior testing. Any help?


locked by HopelessN00b Jan 22 '15 at 3:37

This question exists because it has historical significance, but it is not considered a good, on-topic question for this site, so please do not use it as evidence that you can ask similar questions here. This question and its answers are frozen and cannot be changed. More info: help center.

closed as off topic by splattne Jan 22 '12 at 9:37

Questions on Server Fault are expected to relate to server, networking, or related infrastructure administration within the scope defined by the community. Consider editing the question or leaving comments for improvement if you believe the question can be reworded to fit within the scope. Read more about reopening questions here.If this question can be reworded to fit the rules in the help center, please edit the question.

To be more specific, I would like to find a virtual lab that allows me to design my own topology as well. – Zen Master Jul 13 '11 at 13:34

If you can get your hands on an actual IOS load, you should check out the GNS3 Network simulator. With it you can build virtual routers running real versions of Cisco IOS and test out almost anything you need.

It's not all that easy to setup, but the documentation is very good and if you read it, you can do it.

i dont think its as painful to setup as it used to be, at least as long as you dont want the virtual infrastructure to interact with anything real. – Sirex Jul 13 '11 at 14:09
Thanks for the info. I downloaded GNS3, but it is so incredibly annoying. It has preset nodes, and I am unable to get it to add a 3750 to the list of nodes. The switch node that is already present will not allow me to add more than 1 vlan for a dot1q trunk interface. I am unable to add a G1 card to 7206 node, but can add individual GigE interfaces to the available slots. Problem is, after I add a GigE interface, configure it, save it, and go back to it, it is no longer there. Just disappears. Grrrr. So Buggy – Zen Master Jul 13 '11 at 18:08
hrmm... i really haven't spent much time with it, there are good FAQs out there for which IOS versions and hardware emulations are the best to use. you may not be able to use the exact same stuff as you use physically, best of luck! – SpacemanSpiff Jul 13 '11 at 18:35
its pretty good, but it is a full virtual lab package so the learning curve is a little steep, on the other hand it uses the real IOS images so yuo get everything a real router can do. packet tracer is a doddle to setup but you dont get the same level of ability. for your purposes though it's prolly ideal. – Sirex Jul 19 '11 at 7:39

There is unfortunately no such software.

Packet tracer behavior is not always realistic. It's for students and not for real network simulation.

From cisco's website :

Cisco Packet Tracer is a powerful network simulation program that allows students to experiment with network behavior and ask “what if” questions.

Packet Tracer is a cool tool for CCNA candidates, but it really can't be used by CCNP/CCIE candidates.

The dynamips/dynagen/gns3 trio is a good tool to simulate the routing architecture, but has some serious limitations:

  • no switching
  • no isr/isr g2
  • cpu hog

The simulated topologies are hence simplified to L3/routing, and can hide some obvious L2 design flaws.

I see three solutions here:

  • buy your own lab using real cisco gear.
  • rent rack time from some vendor. Google "ccie rack rental" gives a lot of answers.
  • Use Jeremy's lab. It's small compared to the previous ones, but access is free.
Your answer is most correct. The software is maybe to toy with, but is unreliable and not good for training. Consider the following output I got from Packet Tracer R4#show ip interface brief Serial1/1 YES manual up up R4#ping ..... Success rate is 0 percent (0/5) – T. Webster Apr 19 '13 at 0:56
@T.Webster: Indeed. Unfortunately these bugs hides potential networking issues, so I advise anyone learning networking not to use PacketTracer. – petrus Apr 19 '13 at 14:31

GNS3 is a great suggestion. Some additions - Get a good Config computer for running GNS3. 8GB RAM is optimum for it. (I've run some lower Cisco IOSs with 4GB)

If you don't have a high-end pc, GNS3 can be run on many computers with all of them connected. Look for a tutorial on the same.


in addition to spacemanspiff's gns3 suggestion, check out cisco's own packet tracer software. It's pretty good and does not need the IOS files.

-1. See my answer. – petrus Jul 15 '11 at 12:17

look for packettracer, it is very good and easy to use. It is a real simulator so it involves switching on and off the routers. PT 5.1 is available free of charge to all Cisco® Networking Academy® instructors, students, and alumni. The software can be downloaded from the Packet Tracer resource page on Academy Connection. To access this page, log in to Academy Connection and click the Packet Tracer graphic on the left of the page, then select the appropriate download package for your needs.

-1. See my answer. – petrus Jul 15 '11 at 12:17
did he ever say he is doing CCNP ? – Lucas Kauffman Jul 15 '11 at 15:30
no, but he's trying to design his own corporate topology... – petrus Jul 15 '11 at 18:11
+1 for the sake of fairness, the original question does not provide enough information to simply dismiss Cisco packet tracer completely. – Silverfire Sep 13 '11 at 22:58

Not the answer you're looking for? Browse other questions tagged or ask your own question.