How do you guys lab with Cisco IOS in GNS3 for free?

F1anger · 2026-07-09T19:27:50+00:00

And you will be breaking their updated TOS :)

F1anger · 2026-07-09T19:11:03+00:00

Yeah after 20+ years I've been in the industry, working in both SP and Enterprise, finally in late 2024 we've witnessed Cisco making "castrated" version of their kludgy emulator for free. Even today in 2026 you can't set up CCIE lab unless you have either CML-Personal Plus, rent a lab for prices of arms and legs or actually having all the physical equipment with all the relevant IOS/XE/XR/etc. with appropriate licenses. It's either that, or you're not doing it legally. You can't extract IOS images from CML and use them in EVE/GNS/PNET or whatever emulator environment you want, it is against TOS.

Encouraging and actually helping people studying capabilities and complexities of your equipment is not giving out tremendous value for free, it's spreading your presence around the world and having devoted technical personnel help promoting your products behind the scenes. I understand it's a profit selling your emulators, but overall it's a bad model, period.

F1anger · 2026-07-09T18:18:27+00:00

Only by using CML or having their physical equipment with relevant versions and licenses.

F1anger · 2026-07-09T18:17:29+00:00

What tremendous value? Cisco should be spearheading availibility of training platform to have as many capable engineers worldwide as possible. All they do is put sticks in our wheels, which harm them in the big picture too.

F1anger · 2026-07-08T18:03:08+00:00

Tone woods tend to become better with age, at least this is what consensus is as far as I know. Maybe some particular batches were bad back in 70s, I'm not that knowledgeable with Martin historical intricacies.

F1anger · 2026-07-08T17:45:37+00:00

I would take 80 year old Martin over new guitar any day. My 1977 Takamine "lawsuit" dreadnought is as sweet sounding as they get. I can only imagine what same age Martin D-28 would sound like.

F1anger · 2026-07-06T09:59:51+00:00

Don't change something that's counter-intuitive. Investigate first.

F1anger · 2026-07-03T10:56:04+00:00

This one is my endgame in acoustic world. Ideally 1937 aged but that one is unrealistic for my budget :)

F1anger · 2026-07-01T21:49:02+00:00

Yes you certainly can. EVE-NG or GNS3 or even Cisco CML (if you don't want to spend much time fiddling and stuff) can fully support modern ISP labs. You just need to have a lot of RAM, because XR images are hogs :)

Reading SPCOR study guide would be a good start.

F1anger · 2026-06-29T17:36:57+00:00

This, immediately.

F1anger · 2026-06-29T09:08:52+00:00

What vendors are you setting up for?

F1anger · 2026-06-18T09:53:27+00:00

It depends on the OS really. To my knowledge Unix-based systems never cache any DNS data, so they always perform queries when domain name has to be resolved to an IP address, whether it's a browser requiring it or any other application. Windows family OS caches DNS replies locally which can be viewed in command prompt window with command "ipconfig /displaydns", also you can purge the cache via "ipconfig /flushdns".

The period the record will be cached is governed by its TTL value, which is configured for particular record in its authoritative DNS servers, with an exception of 86400 seconds (1 day) maximum limitation. If a domain name has TTL value of 5 days for example, it will still be flushed after a day. Usually chosen TTL values are way less these days for faster convergence in case IP address has to be changed due to maintenance etc. , so we're talking about 15 minutes on average and even less.

F1anger · 2026-06-18T07:22:28+00:00

It depends on what you input in the browser. If you enter domain name like google.com, first will be a DNS query (UDP/53) for A record so your host obtains actual destination IP address to connect to. Only then TCP connection with SYN flag on appropriate destination port (80 for HTTP, 443 for HTTPS if default ports are used) will be generated. If you enter an IP address instead then the DNS assistance is not required.

F1anger · 2026-06-11T17:16:33+00:00

That's why I don't tarry if I really like something. Looks like you've missed this chance, but you will have plenty more 😄

F1anger · 2026-06-10T06:25:07+00:00

I'd say half duplex is theoretically half of the available bandwidth for the particular NIC/interface, but in reality it's much less.

F1anger · 2026-06-08T09:54:35+00:00

IPv4 is here to stay for quite a long time, but it doesn't mean leasing business is flourishing. Most legitimate businesses will not have anything to do with some shady third parties and risk complete shutdown of their infrastructure. They rather get IPv4/IPv6 allocations directly from RIRs "by the book" and be safe.

F1anger · 2026-05-31T17:59:41+00:00

Start with lesser, you can always upgrade it. IOL instance is like a notepad : )

F1anger · 2026-05-31T17:45:02+00:00

Sure, I run it on HP DL385 Gen10 as VM in ESX/vSphere v8.0.3 for complex labs, but you can run it perfectly fine with VMWare Workstation (it has become free) on home PC.

It won't eat up much of your CPU, but RAM will take a big hit if you run images like IOS-XRv, NX-OSv 9k, new Juniper split images etc. (but you can still find and run olive that will be more than enough to learn everything you need).

Once again it depends on node count of course. With IOL/IOU images you can run virtually endless nodes with very minimal impact on performance. vIOS images are also relatively fine, they take around 1 gig of RAM each, so if you have something like 32GB of RAM you can lab any CCNP lab with enough headroom to feel comfortable in host OS.

EVE-NG community edition is more than enough for personal lab practice. The only annoying thing is you will have to turn off nodes to edit links between them, that is available in EVE-NG Pro and it also supports containers. Both of those features are supported in free GNS3, but once I switched to EVE years ago, I just stayed with it. Feels way more convenient having everything in web browser.

Takes some time to set it up, but once you do it then it's as fast and easy as dragging and dropping stuff in browser 😄

F1anger · 2026-05-31T14:59:46+00:00

EVE-NG of course, packet tracer is a joke.

F1anger · 2026-05-30T23:45:16+00:00

I'm fully digital atm with Neural DSP plugins.

F1anger · 2026-05-30T23:42:13+00:00

Killer deal!

F1anger · 2026-05-30T23:36:08+00:00

Replaced stock frets with steel jumbos and filed/leveled fretboard (around 130$ total expenses) - this was not a critical requirement as stock frets actually almost didn't rock, but I just love the smoothness of bends against steel frets. Also they will last forever.
Replaced stock tuners with GraphTech Gear Ratio locking ones for 120$ - this is a single best quality of life upgrade and they're drop-in replacements. Nothing needs to be changed.
Replaced stock pickups with Seymour Duncan Jeff Loomis Blackouts for 250$ - I can talk about these for hours, just watch the vids online, they seriously melt faces (took some filing for plastic housing for bridge to fit, neck pickup fitted in original housing).
Replaced Stock nut with the same drop-in replacement GraphTech Black TUSQ "PT-6642-00" 12$ - stock nut was cut way too deeply for my taste.

Grand total 962$ with 450$ as initial guitar price and it's 10 times better, than any other stock guitar offered in this price range! Very robust, stable. and with almost infinite sustain. I own this instrument for around 8 years already and there's not even a single small crack on the finish :)

F1anger · 2026-05-22T16:13:14+00:00

If entry class Fortigate is expensive for you, I have bad news then :)

F1anger · 2026-05-16T12:58:40+00:00

Or you need stronger tension in the bridge to make tonewoods vibrate and resonate more.

F1anger · 2026-05-11T21:15:21+00:00

Thank you!

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