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Linux: Limit IPv6 connectivity to specific programs

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Re: Linux: Limit IPv6 connectivity to specific programs

#11

Post by IgorPartola »

wmf wrote: post #7
lgbr wrote: post #6

Security aside, this is even useful for new deployments of IPv6. It seems a lot of people have IPv6 networks that are less favorable for some traffic than their IPv4 networks. Some are running their IPv6 through tunnels. As soon as you enable IPv6 on your desktop, suddenly Firefox or Chromium will prefer IPv6 for any website with a AAAA record, which adds a ton of latency and reduces bandwidth. But theoretically, I c…

IPv6 is no longer necessarily preferred due to happy eyeballs. http://tools.ietf.org/html/rfc6555

I did something independent of happy eyeballs (I consider my implementation actually superior in some ways as it aims to improve connection latency on all networks), but when I tried to get in front of some browser developers (by posting on HN), I was told by a Chrome networking dev that they tried it and decided that it wasn't worth it. He cited something about how the performance was actually worse than before. The impression that I got was that Happy Eyeballs was not actually widely adopted.

Re: Linux: Limit IPv6 connectivity to specific programs

#12

Post by [deleted] »

IgorPartola wrote: post #10
Tomdarkness wrote: post #5

> "The main problem is to secure an IPv6 network which is much more complicated than using a typical IPv4 network consisting of a router and several devices behind it." Does anyone know why this is the case? I'm not a network security expert but to me I don't see how IPv4/v6 makes a different in terms of security. I'd assume that each computer on the network could most likely be assigned a public IPv6 address rather…

There is nothing special about firewalling off IPv6. NAT is not a security feature. The problem is that most consumer "routers" that people use nowadays are really: a router, a switch, a wireless access point, a firewall, and who knows what else. Here are some sample rules for firewalling off IPv4 (typed from memory, so use with caution): iptables -A INPUT -i lo -j ACCEPT iptables -A INPUT -m conntrack --ctstate ESTA…

[deleted]

Re: Linux: Limit IPv6 connectivity to specific programs

#13

Post by noja »

IgorPartola wrote: post #10
Tomdarkness wrote: post #5

> "The main problem is to secure an IPv6 network which is much more complicated than using a typical IPv4 network consisting of a router and several devices behind it." Does anyone know why this is the case? I'm not a network security expert but to me I don't see how IPv4/v6 makes a different in terms of security. I'd assume that each computer on the network could most likely be assigned a public IPv6 address rather…

There is nothing special about firewalling off IPv6. NAT is not a security feature. The problem is that most consumer "routers" that people use nowadays are really: a router, a switch, a wireless access point, a firewall, and who knows what else. Here are some sample rules for firewalling off IPv4 (typed from memory, so use with caution): iptables -A INPUT -i lo -j ACCEPT iptables -A INPUT -m conntrack --ctstate ESTA…

> NAT is not a security feature.

Why?

Re: Linux: Limit IPv6 connectivity to specific programs

#14

Post by lifeisstillgood »

On this subject, sort of, if I want to dump the commercial routers and replace with eithe a Linux install on a commercial router or a x86 box that is not too chunky / loud Where do I go for readme and instructions and community?

I can find some old Linux on linksys sites but not a lot recently

Re: Linux: Limit IPv6 connectivity to specific programs

#15

Post by justincormack »

lifeisstillgood wrote: post #14

On this subject, sort of, if I want to dump the commercial routers and replace with eithe a Linux install on a commercial router or a x86 box that is not too chunky / loud Where do I go for readme and instructions and community? I can find some old Linux on linksys sites but not a lot recently

Openwrt https://openwrt.org/ is where most of the docs are, though there are other similar projects. The most supportive vendor is probablr Netgear now http://www.myopenrouter.com/

Re: Linux: Limit IPv6 connectivity to specific programs

#16

Post by dfc »

lgbr wrote: post #6

Security aside, this is even useful for new deployments of IPv6. It seems a lot of people have IPv6 networks that are less favorable for some traffic than their IPv4 networks. Some are running their IPv6 through tunnels. As soon as you enable IPv6 on your desktop, suddenly Firefox or Chromium will prefer IPv6 for any website with a AAAA record, which adds a ton of latency and reduces bandwidth. But theoretically, I c…

At home my HE tunnel is snappier than the plain ipv4 from rr. The weird thing is it is not just a case of user perception (mine). One of the upstream s1 ntp boxes I sync with has ipv4 and ipv6 and is relatively close. I set one of my s1s to sync with both the ipv4 and ipv6 addresses of the machine and the ipv4 clock displayed a lower delay and less jitter while the offsets were seasonably close.

Re: Linux: Limit IPv6 connectivity to specific programs

#17

Post by justincormack »

lgbr wrote: post #6

Security aside, this is even useful for new deployments of IPv6. It seems a lot of people have IPv6 networks that are less favorable for some traffic than their IPv4 networks. Some are running their IPv6 through tunnels. As soon as you enable IPv6 on your desktop, suddenly Firefox or Chromium will prefer IPv6 for any website with a AAAA record, which adds a ton of latency and reduces bandwidth. But theoretically, I c…

You can always just drop ipv6 packets for certain destination ports (eg 80) with iptables if you know the application (like a browser) will be ok. Which is much simpler.

Re: Linux: Limit IPv6 connectivity to specific programs

#18

Post by infographic- »

noja wrote: post #13
IgorPartola wrote: post #10

Earlier quoted context omitted.

There is nothing special about firewalling off IPv6. NAT is not a security feature. The problem is that most consumer "routers" that people use nowadays are really: a router, a switch, a wireless access point, a firewall, and who knows what else. Here are some sample rules for firewalling off IPv4 (typed from memory, so use with caution): iptables -A INPUT -i lo -j ACCEPT iptables -A INPUT -m conntrack --ctstate ESTA…

> NAT is not a security feature. Why?

https://encyclopediadramatica.se/Steve_Gibson

Re: Linux: Limit IPv6 connectivity to specific programs

#19

Post by Already__Taken »

akira2501 wrote: post #3

This seems to take the long way around. I wonder why they didn't consider just using the firewall to control network traffic; unless you really need your applications to be completely unaware of IPv6, but so far, I've not experienced that problem. Also, requiring root privileges for launch is a bit of a burden in some use-case scenarios.

Not exactly a common use case or linux related but my Red Alert 2 game patched for tcp/ip instead of IPX support it shipped with will only let you into LAN game lobbies on ipv6, you can't see any games to join. ipv4 and it works like a charm.

My point is just that I'm sure some very very weird stuff can happen with software.

Re: Linux: Limit IPv6 connectivity to specific programs

#20

Post by marios »

lifeisstillgood wrote: post #14

On this subject, sort of, if I want to dump the commercial routers and replace with eithe a Linux install on a commercial router or a x86 box that is not too chunky / loud Where do I go for readme and instructions and community? I can find some old Linux on linksys sites but not a lot recently

If you with the commercial router route, checkout OpenWRT / DD-WRT / Tomato. There are several forks, so depending on what features you want, and what hardware you have, you may opt for a different version. If you go with an existing x86/amd64, just install your favorite distro and start reading up on iptables configuration and management. While iptables to be quite powerful in terms of features, I find its' syntax is painful. There are several projets aiming to simplify this, by generating rules from another, simpler, DSL but it adds complexity. This is why I prefer PF, but that requires you to install OpenBSD instead of Linux. If you know your way around UNIX, and are ready to read up the FAQ and man pages, this shouldn't be a problem :).
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