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submitted 4 months ago* (last edited 4 months ago) by lambalicious to c/programmer_humor@programming.dev

Today in our newest take on "older technology is better": why NAT rules!

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[-] sep@lemmy.world 92 points 4 months ago

I felt dirty! and broke so much shit when i had to implement NAT on networks in the mid 90's. Nowdays with ipv6 and getting rid of NAT is much more liberating. The difference is staggering!

  • you do not need NAT any longer, firewall is the security, just like on ipv4, just less obscurity.
  • you do not need dns views, to workaround NAT any more
  • you do not need hairpin NAT to workaround NAT any more
  • you do not need to renumber to resize a network. they are always /64, and the answer to how many hosts can it fit is: ALL of them!
  • many ALG's will be unnecessary since there is not NAT.
  • vpn's are easier, since it can be the same address both inside and outside the vpn, the firewall (or host even) enforces the encryption.
  • vpn's are MUCH easier since you will have less rfc1918 collisions due to some other network using the rfc1918 of the vpn's network
  • vpn's are MUCH MUCH easier since you will have less rfc1918 collisions due to you using the rfc1918 of the vpn partner network, to 1:1 nat a previous vpn network you collided with some months ago... ARGH!!!
  • vpn are generally less required, heck i swear 95% of the time the VPN are just to workaround the NAT problem and the data is pointlessly double or triple encrypted.
  • you can make more granular firewall rules (eg the spesific host, or network of the source address, instead of the whole enterprise's public ip) this is real tangible improved security, where any random machine in a network you do not control. do not automatically have openings into your own network.
  • firewall objects can if it is suited easily use and depend on FQDN DNS objects when allowing traffic. reducing the need of coordinating firewall object ip address changes between 15 companies.
  • firewall rules are easier, more readable, and much more predictable how they will work. All the hairpin nat, public to private nat, private to public nat for a thing that need a different public ip, 1:1 nat for a separate zone, NAT to a vpn or 50 (where 10 of them are 1:1 nat due to collisions, making you require 4 dns views of the same ip space!! ) very quickly gets messy and unreadable. this is probably the largest security benefit. just to reduce the complexity.
  • much easier to get people to use dns, since nobody wants to remember ipv6 addresses :D
  • nibbles in the ipv6 address can have meanings you assign to them, making the networks and structure both easy to remember and logically structured.
  • aggregating routes becomes very easy if you design your network that way.
  • firewall policies can become easier if you design your network that way.
  • your routing tables is leaner and easier, and of a better consistency. We have 1 large public ipv6 prefix, but 25ish ipv4 prefixes of all kinds of various sizes.
  • no need to spend $$ to buy even more ipv4 prefixes.
  • no need to have spent hundreds of $$ on a new ipv4 prefix only to be unable to use them for over a year because you need to sanitize the addresses from all the reputation filters. and constantly hound geo ip database providers to update the new country of the prefix. (i am bitter,, can you tell..)
  • did i mention no need to renumber since you need to grow the /24 to /23 due to to many hosts in a network ?
  • did i mention no need to renumber 2 /24's to /25's to make space for that larger /23.
  • you do not even need any ipv4 addresses any more, use a public NAT64 service, for outgoing. and for incoming just use one of the many free public ipv4 to ipv6 proxies for your services online. for a homelab i really like http://v4-frontend.netiter.com/ (go support them) But most large business l networks use cloudflare, or akamai
  • since you do not need your ipv4 address space any more, you can ~~sell them for a profit $$$ ~~ return them to the RIR and give some address space to one of the thousands of companies struggling because they do not have any IPv4 : https://www.ripe.net/manage-ips-and-asns/ipv4/ipv4-waiting-list/
  • much lower latency on ipv6, since you do not go across a cloud based ipv4 to ipv6 proxy in order to reach the service ;)

Now the greatest and best effect of ipv6 is none of the above. It is that with ipv6 we have a slim hope of reclaiming some of what made the Internet GREAT in the first place. When we all stood on equal footing. Anyone could host their own service. Now we are all vassals of the large companies that have made the common person into a CGNAT4444 using consumer mindlessly lapping up what the large company providers sees fit to provide us. with no way to even try to be a real and true part of the Internet. Fight the companies that want to make you a eyeball in their statistic, Set up your own IPv6 service on the Internet today !

[-] lambalicious 21 points 4 months ago

I felt dirty!

"Senpai, route me like one of your French ISPs"

[-] DogWater@lemmy.world 14 points 4 months ago

Sir this is a Wendy's

JK that's a lot of good info

[-] jdeath@lemm.ee 3 points 4 months ago

i got like a third through it before scrolling to the bottom to see how long it was. omg! should be the canonical example of the opposite of a shitpost ha

[-] Mr_Dr_Oink@lemmy.world 2 points 4 months ago

Its as long as an ipv6 address

[-] BarbecueCowboy@lemmy.world 11 points 4 months ago

If all that is true, then why do I still hate ipv6 so much.

[-] sep@lemmy.world 15 points 4 months ago

I assume the normal fear of unknown things. It is hard to hate ipv6 once you have equivalent competence in ipv4 and ipv6.

[-] DivineBurke@lemmy.world 5 points 4 months ago

I'd bet it's this little bugger " : "

It is for me.

[-] Mr_Dr_Oink@lemmy.world 1 points 4 months ago

The : is ok. I dont struggle with the shortening part. I struggle the "everything else" part.

[-] Thiakil@aussie.zone 5 points 4 months ago
[-] Valmond@lemmy.world 1 points 4 months ago* (last edited 4 months ago)

What is localhost now again...

Edit, remember you could use 127.0.0.1, but then it was changed to like 127.0.0.1......something....ff

So guess I was wrong :-) thanks for the info!

[-] zewm@lemmy.world -1 points 4 months ago

For me is because it’s so fucking slow. As soon as I disable ipv6 on every device it has better speeds.

IPv6 is trash.

[-] orangeboats@lemmy.world 11 points 4 months ago

Tell that to your ISP which has fucked their IPv6 deployment up. In my experience IPv6 is actually faster since it bypasses the IPv4 CGNAT.

On busy days my IPv4 connection can get as slow as 15KB/s, now that's trash.

[-] efstajas@lemmy.world 6 points 4 months ago

Lol that's ridiculous. There's nothing about ipv6 that'd make it any slower

[-] frezik@midwest.social 2 points 4 months ago

There's one practical thing. Routers have had years to optimize IPv4 routing, which has to be redone for IPv6. Same with networking stacks in general.

In theory, IPv6 should be faster by not having to do bullshit like CGNAT. There's every reason to think it'll match that advantage if we just make it happen.

[-] dan@upvote.au 3 points 4 months ago* (last edited 4 months ago)

In the USA, around 50% of Google traffic and 60% of Facebook traffic goes over IPv6. The largest mobile carriers in the US are nearly entirely IPv6-only too (customers don't get an IPv4 address, just an IPv6 one), using 464XLAT to connect to legacy IPv4-only servers. I'm sure we'd know if routing with IPv6 was slower. Google's data actually shows 10ms lower latency over IPv6: https://www.google.com/intl/en/ipv6/statistics.html#tab=per-country-ipv6-adoption

[-] frazorth@feddit.uk 1 points 4 months ago

That doesn't make it "trash".

[-] dan@upvote.au 2 points 4 months ago

Google's data shows that IPv6 is usually faster. Their metrics show an average of 10ms less latency over IPv6 in the USA and Canada: https://www.google.com/intl/en/ipv6/statistics.html#tab=per-country-ipv6-adoption

[-] GTG3000@programming.dev 4 points 4 months ago

Imagine actually having ipv6 available through your ISP.

...and ever if my ISP actually provided one, getting a static one costs money so there's no difference in the end.

[-] sep@lemmy.world 3 points 4 months ago

I guess I am lucky. 3 out of 3 isp's available from in my region provide IPv6 with a dhcp-pd assigned stable address by default. (Norway)

[-] GTG3000@programming.dev 2 points 4 months ago

Yeah, here in Russia the ISPs and IT infrastructure guys seem to be treating IPv6 like it has cooties. I can't find an article (and it'd be in russian anyway) but as far back as 2022, if you get IPv6 you can expect a variety of issues with it, ranging from "you need to reboot your router every once in a while" to "you technically have v6 but good luck actually browsing v6 internet".

And of course, why would they give you a stable IP when they can charge for it :T. At least it's only a third the price of a stable IPv4.

My current ISP technically provides v6 according to their site - but my connection doesn't have it, and since there's nothing about it in the years-old contract, I'd need to redo that if I want to complain.

[-] sep@lemmy.world 2 points 4 months ago

You have my sympathy. I do not know of a sure way to get isp's to behave. Espesially not if they have regional monopoly

[-] GTG3000@programming.dev 2 points 4 months ago

There are usually plenty of choices for ISPs here, actually. But switching between them isn't likely to give me IPv6 since either they share a magistral or the hardware is just plain old. That, and IPv6 is just not a thing anyone markets.

...and with the current fuckery going on, I doubt many of them have budget for big upgrades. Or maybe even access to hardware to buy.

[-] Kazumara@discuss.tchncs.de 2 points 4 months ago

I just get that included. Like the Norwegian guy, but in Switzerland from Init7

[-] dan@upvote.au 4 points 4 months ago

This is one of the best comments I've ever read on Lemmy. Thanks for writing it. I fully agree with all your points!

[-] sep@lemmy.world 2 points 4 months ago

Thank you! :) I also notice i compleatly forgot the port exhaustion issue we see with larger networks behind roo few ipv4 NAT addresses..

[-] stoy@lemmy.zip 2 points 4 months ago

But IPv4 addresses are easier to remember!

/s

I could see a point of having home networks stay on IPv4 and NAT with an external v6 address.

That would keep the current security model for home networks where we can assume general tech litteracy is low.

[-] sep@lemmy.world 4 points 4 months ago

That is not how it works. You can have a home network on ipv6. And it can reach all of ipv4 via nat ( just like ipv4 do today). A net with only ipv4 can not reach any ipv6 without a proxy that terminst the v4 connection and make a new v6 connection. since ipv6 is backwards compatible. But ipv4 is naturally not forwards compatible.

Also it is the default deny of the stateful firewall that always coexist with NAT, since NAT depends on that state, that is the security in a NAT router.
That default deny is not in any way dependant on the NAT part.

[-] stoy@lemmy.zip 2 points 4 months ago

Interesting, I thought NAT could handle it...

[-] sep@lemmy.world 3 points 4 months ago

If there is a ipv6 service online. That you want to reach from a v4 only client. You can set up a fixed 1:1 nat on your firewall where you define a fake internal ipv4 address -> destination NAT onto the public ipv6 address of the service. And SRC NAT64 embed your clients internal v4 into the source ipv6 for the return traffic. And provide a internal dns view A record pointing to the fake internal ip record. It would work, but does not scale very well. Since you would have to set this up for every ipv6 ip.

A better solution would be to use a dualstack SOCKS5 proxy with dns forwarding where the client would use the IPv6 of the proxy for the connection. But that does not use NAT tho.

The best solution is to deploy IPv6 ofcourse. ;)

[-] gamma@programming.dev 1 points 4 months ago

You could still NAT between v6's though.

[-] Tja@programming.dev -3 points 4 months ago

Con: you are now even more dependent on DNS, increasing the blast radius even more ~~if~~ when it breaks.

[-] sep@lemmy.world 6 points 4 months ago

But DNS rarely break. The meme about it beeing DNS's fault is more often then not just a symptom of the complexity of IPv4 NAT problem.

If i should guesstimate i think atleast 95% of the dns issues i have ever seen, are just confusion of what dns views they are in. confusion of inside and outside nat records. And forgetting to configure the inside when doing the outside or vice verca. DNS is very robust and stable when you can get rid of that complexity.

That beeing said, there are people that insist on obscurity beeing security (sigh) and want to keep doing dns views when using IPv6. But even then things are much easier when the result would be the same in either view.

[-] Tja@programming.dev 2 points 4 months ago

I broke DNS plenty of times in my homelab independent from NAT. In the last few months:

  • didn't turn off DNS server in a wifi router set up as bridged access point
  • dnsmasq failing to start because I removed an interface
  • dnsmasq failing to start because the kernel/udev didn't rename an interface on time
  • dnsmasq failing to start because hostapd error didn't set proper interface settings
  • forgot to remove static DNS entries in /etc/hosts used for testing
  • forgot to remove DNS entries from /etc/resolve.conf after visiting a friend and working on his setup

Yes, most of them is my dumb ass making mistakes, but in the end it's something that constantly breaks and it helps knowing the IP addresses of my servers and routers.

Aditionally, obscurity is a security helper. The problem is relying only on obscurity. But if I have proper firewall rules in place and strong usernames and passwords I still prefer if you don't even know the IP addresses of my servers on top of that (in case I break some of the other security layers).

[-] Mr_Dr_Oink@lemmy.world 2 points 4 months ago

That beeing said, there are people that insist on obscurity beeing security (sigh) and want to keep doing dns views when using IPv6. But even then things are much easier when the result would be the same in either view.

OMG!!

This guys a bee! Everybody run!!!!

this post was submitted on 19 Jun 2024
315 points (85.6% liked)

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