[Solved] hosts file with ipv6 disabled

WonderWoofy · 2012-08-19 18:45:45

Hello community!

So I have disabled ipv6, as it was causing various issues and Comcast has not yet implemented ipv6 in my area. Disabling was no problem, but nowhere can i find information regarding whether or not to keep the ipv6 line in the hosts file. Should I comment it out?

For clarity I am referring to the ::1 line. Will commenting it out be problematic, or will keeping it be problematic, or does it not really matter? I know having an improperly configured hosts file can cause all sorts of network issues, so I am very curious.

Right now I have it commented out, and I have not noticed any real problems, but I also have a Realtek wireless card using rtl8192ce, which is not the most stable driver/connection. Thus my connection is kind of intermittently crappy. So I am curious if I am making my connection crappier than it was before.

Thanks in advance!

Edit: Of course as soon as I posted this, I found an answer. The Debian wiki recommends commenting it out when completely disabling ipv6. So to those who at least read my post, thanks!

Last edited by WonderWoofy (2012-08-19 20:19:44)

ghen · 2012-08-20 19:05:29

For most people it should cost less time to figure out IPv6 correctly (with or without actual connectivity, but that's not even relevant for ::1), than to try to disable it everywhere. It's the new Internet, accept it! :-)

I went the opposite way and removed the 127.0.0.1 line from /etc/hosts everywhere, without any harm. I once actually removed 127.0.0.1 from the lo interface too, but too many applications have it hardcoded, instead of using the "localhost" name. :-(

Last edited by ghen (2012-08-20 19:11:21)

WonderWoofy · 2012-08-21 00:46:23

Yes I know it is the new way of the internets, but from what I have gathered (and I may be totally wrong on this, in which case, please tell me) the ISP's are incredibly slow to implement this standard across the web.

I am a Comcast customer and although they have begun to set up ipv6 in some areas it is not yet universal. I was able to confirm from them recently that my area is still an ipv4 only area. So I figured if disabling it now would resolve various issues, why not? When ipv6 is implemented, I will turn it back on and deal with that when the time comes.

I do appreaciate your input though!

cfr · 2012-08-21 01:35:37

@WonderWoofy,

Do you have a link for the Debian wiki? I'd like to understand the reasoning.

To be honest, I didn't even realise that line was for ipv6. Since I've disabled it in sysctl.conf, I should probably consider commenting it out, too. Right now, I seem to be loading firewall modules for ipv6, mind, which seems like slightly more security than can be strictly necessary if the thing is disabled...

@ghen,

It isn't, that I know of, a matter of "figuring it out correctly". Having ipv6 enabled can screw up ipv4 connections. Having it enabled prevents me from connecting to the internet at all on one of the networks I use. As I understand it, a properly configured network shouldn't do this but when the official IT support people say the problem is that you have ipv6 enabled, you don't have much choice. (And it isn't as if there's anything to be gained by having it enabled.)

WonderWoofy · 2012-08-21 02:05:43

@cfr - Yeah, here is the link http://wiki.debian.org/DebianIPv6#How_to_turn_off_IPv6 but it doesn't say much about why specifically this is needed other than it may f* w/ sshd. I would have to imagine that if you disabled it on your machine, iptables6 is probably not needed.

cfr wrote:

(And it isn't as if there's anything to be gained by having it enabled.)

From what I have read and what Comcast tells me, there are areas where there is the opposite problem of your not being able to connect w/ ipv6 enabled. I guess they have actually set up some areas that are running ipv6. I think there is still an ipv4 compatibility mode, but it can cause problems in the same way as you or leaving ipv6 enabled.

cfr · 2012-08-21 02:26:32

Thanks for the link.

I'm sure iptables6 isn't needed. I'm just paranoid. Actually, I worry I'll forget to enable it if ipv6 ever comes to be... I don't trust the reliability of my future selves since I fear they will be too much like my past ones...

I meant there's nowt to be gained by having it enabled if none of the networks you use have ipv6. I'm sure there's a point if they do.

Last edited by cfr (2012-08-21 02:26:53)

WonderWoofy · 2012-08-21 03:22:20

I think that at some point they will *have* to since the current ipv4 addresses are already filled (albiet with some really useless crap). I would really like it if they just went ahead and did it rather than staying in this terrible limbo. I think the rollout of ipv6 could ahve been much better. Unfortunately, in the US at least, the ISP's have far too much power over the consumers. I guess that is also why Comcast is rated one of the fastest in the country, and my connection is 25Mb/s, while other tech developed countries easily acheive 100Mb/s at far lower prices. They screw us because they *can* and we let them.

ghen · 2012-08-21 07:50:25

Even without exterior IPv6 connectivity, you should be able to leave IPv6 enabled and have everything working properly. As long as you have no (bogus) IPv6 default route, connections should fall back gracefully (ie. without timeout) to IPv4. Especially ::1 should be no issue...

Remember that countless Windows (Vista/7) and MacOS machines are out there with IPv6 enabled but IPv4-only connectivity, and they are working well too, right?

If you do have eg. rogue IPv6 routers advertizing prefixes on your local network segment and foobar'ing your connectivity, you can set sysctl net.ipv6.conf.default.accept_ra=0 to ignore them.

cfr · 2012-08-21 15:22:39

I know it can work - at home it works fine even though my ISP doesn't have ipv6 (because "there's no demand"). But at work, it doesn't work at all. Since these are the two networks I regularly use, disabling it is a straightforward work around for now.

Since the campus machines are all XP, I guess they don't have issues. And you can disable ipv6 in OS X - at least, you used to be able to.

WonderWoofy · 2012-08-21 15:31:47

@ghen - I really don't think that cfr or I am disagreeing with you that it *should* work with proper configuration and such, and also that it is the way of the future. But if I am staying on a limited number of networks and this provides a solution for the time being, I figure why not use it and cross the ipv6 bridge when I come to it.

I also had this problem with OSX on the same network, so disabled it there too. I still use OSX 10.6.8 so as far as I know it is still possible.

Arch Linux

#1 2012-08-19 18:45:45

[Solved] hosts file with ipv6 disabled

#2 2012-08-20 19:05:29

Re: [Solved] hosts file with ipv6 disabled

#3 2012-08-21 00:46:23

Re: [Solved] hosts file with ipv6 disabled

#4 2012-08-21 01:35:37

Re: [Solved] hosts file with ipv6 disabled

#5 2012-08-21 02:05:43

Re: [Solved] hosts file with ipv6 disabled

#6 2012-08-21 02:26:32

Re: [Solved] hosts file with ipv6 disabled

#7 2012-08-21 03:22:20

Re: [Solved] hosts file with ipv6 disabled

#8 2012-08-21 07:50:25

Re: [Solved] hosts file with ipv6 disabled

#9 2012-08-21 15:22:39

Re: [Solved] hosts file with ipv6 disabled

#10 2012-08-21 15:31:47

Re: [Solved] hosts file with ipv6 disabled

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