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mgnut57
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Joined: 12 Jan 2008
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 Posted: Wed Dec 04, 2019 4:50 am Post subject: ip6tables |
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I am just starting to try to understand and configure IPv6 on my home network.
I can run "dhclient -6 ..." and get a working IPv6 address. The next question is ip6table rules.
I currently run a tight and complex set of iptables rules. Would it work to simply clone every iptables rule to an ip6tables rule (with appropriate changes for IP addresses)? |
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Ant P.
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Joined: 18 Apr 2009
Posts: 6920
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| Posted: Wed Dec 04, 2019 7:03 am Post subject: |
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| Short answer yes, but in the long term you'd be better off transitioning to nftables where one ruleset can do both (and there's no risk of leaving one completely unfirewalled, as most iptables users currently are). |
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mike155
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Joined: 17 Sep 2010
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Location: Frankfurt, Germany
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| Posted: Wed Dec 04, 2019 4:41 pm Post subject: Re: ip6tables |
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| mgnut57 wrote: | | I can run "dhclient -6 ..." and get a working IPv6 address. The next question is ip6table rules. |
You can use dhclient to get an IPv6 IP address, but you don't have to - IPv6 supports stateless autoconfiguration (SLAAC). |
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NeddySeagoon
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| Posted: Wed Dec 04, 2019 6:12 pm Post subject: |
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mgnut57,
Like mike155 says, IPv6 just works. Your ISP turns it on one day and you have a public IPv6 address.
Nothing between you and the big bad internet apart from lots of empty address space and you didn't even know it.
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NeddySeagoon
Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail. |
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mgnut57
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Joined: 12 Jan 2008
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| Posted: Thu Dec 05, 2019 5:08 am Post subject: |
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| NeddySeagoon wrote: | mgnut57,
Like mike155 says, IPv6 just works. Your ISP turns it on one day and you have a public IPv6 address.
Nothing between you and the big bad internet apart from lots of empty address space and you didn't even know it. |
All my ethernet interfaces all appear to have IPv6 addresses, but they don't work. When I used "dhclient -6", I got a working IPv6 address.
What's the point of and where did the IPv6 addresses come from? Even the machines behind the router have IPv6 addresses. I have assumed they are some kind of default address. Is this not true?
I just found a reasonable default set of ip6tables and set that up so that I can safely test ipv6.
Last edited by mgnut57 on Thu Dec 05, 2019 6:05 am; edited 1 time in total |
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ali3nx
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Joined: 21 Sep 2003
Posts: 732
Location: Winnipeg, Canada
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| Posted: Thu Dec 05, 2019 5:25 am Post subject: |
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One thing i discovered when learning ipv6 in more recent years since my isp in canada flipped the switch on live ipv6 support is the difference between publicly routable ipv6 and the non routable local address ranges.
Currently i don't have a modem from my isp that provides ipv6 so portraying the differences with examples is not currently an easy option however i found this ipv6 course that's not entirely free but does have many concepts available without requiring purchasing the entire course. Still the free course material offered offers some great perspective.
The sections on ipv6 address types and routing are concepts anyone needs to learn because the ipv4 death knell is already here and not going away.
https://networklessons.com/ipv6
It was hilarious discovering my router had been assigned an entire /64 subnet the first time i tested it. Felt like i had my own planet to terraform and do with as i pleased 
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NeddySeagoon
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Joined: 05 Jul 2003
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| Posted: Thu Dec 05, 2019 11:52 pm Post subject: |
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ali3nx,
You are not supposed to subnet a /64 but you can. That's why you have a /64. Your ISP can't give you any less.
When I signed up for a trial (free) I got a /48 for my subnets and a separate /64 just for my ppp uplink.
If you have a global scope IPv6 address it will start with a 2. That's the big bad internet.
IPv4 isn't going away any time soon.
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NeddySeagoon
Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail. |
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mgnut57
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Joined: 12 Jan 2008
Posts: 308
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| Posted: Fri Dec 06, 2019 3:31 am Post subject: |
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| NeddySeagoon wrote: | mgnut57,
Like mike155 says, IPv6 just works. Your ISP turns it on one day and you have a public IPv6 address.
Nothing between you and the big bad internet apart from lots of empty address space and you didn't even know it. |
What if it doesn't?
My experience is that my interface doesn't have an IPv6 address (other than the link local address). Is it possible that my ISP (Comcast) could support dhcp for IPv6, but not autoconfiguration?
Or is there an iptables or kernel configuration that I need to set? I could not find anything in the kernel config and my ip6tables config was wide open (default allow, no rules).
Update: having read some more, I wonder if the problem is that my cable modem doesn't support SLAAC. |
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