Arch Linux

dviktor

Member

From: Moscow

Registered: 2015-10-18

Posts: 162

IPv6 router

I've set up IPv4 router and things look great.
Now I want to add IPv6 routing capability for it and I've stuck here.

My ISP gives me IPv6 address and external network interface configured fine - I obtain configuration via stateless mode, can ping IPv6 google and do neighbor discovery. Now I try to figure out what configuration should be done on internal interface. I tried to assign IPv6 address by hand from ULA space and then specify desired dhcp-range in dnsmasq.conf but my LAN clients are unable to get desired configuration and stays with link-local addresses instead. Also I tried to enable Router Advertisement with radvd as described in wiki but clients are still unable to get addresses from my prefix (I'm bit unsure what settings should be applied to my internal interface in that case; I use netctl if that matters). Forwarding is enabled.

What am I missing?

Last edited by dviktor (2019-02-16 00:39:59)

fukawi2

Ex-Administratorino

From: .vic.au

Registered: 2007-09-28

Posts: 6,231

Website

Re: IPv6 router

You should have a /64 from your ISP for the link between your router and them.

They should then issue you another /56 or /48 that you can then slice up into /64's and then advertise on your internal LAN using radvd. You can't use ULA to access the rest of the internet as IPv6 doesn't have NAT like IPv4. ULA is for internal connectivity only and is optional. Since you're just starting out, I'd suggest not worrying about them for now.

---

Are you familiar with our Forum Rules, and How To Ask Questions The Smart Way?

BlueHackers // fscanary // resticctl

dviktor

Member

From: Moscow

Registered: 2015-10-18

Posts: 162

Re: IPv6 router

Yes, my external i/face already have IPv6 address, I obtain it via IP6=stateless in netctl profile:

eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
...
    inet6 2a00:f480:4:266:7a24:afff:fe04:6672/64 scope global dynamic mngtmpaddr 
       valid_lft 2592000sec preferred_lft 604800sec
    inet6 fe80::7a24:afff:fe04:6672/64 scope link 
       valid_lft forever preferred_lft forever

I have set radvd daemon as described in ArchWiki:

interface wlan0 {
  AdvSendAdvert on;
  MinRtrAdvInterval 3;
  MaxRtrAdvInterval 10;
  prefix ::/64 {
    AdvOnLink on;
    AdvAutonomous on;
    AdvRouterAddr on;
  };
};

radvd starts successfully, but my LAN clients are still unable to get any IPv6 address.

What IPv6 settings should be configured for LAN interface? Should I enter static IP for it? Forwarding is enabled, ip6tables rules are empty

fukawi2

Ex-Administratorino

From: .vic.au

Registered: 2007-09-28

Posts: 6,231

Website

Re: IPv6 router

You'll need to use a DHCPv6 client to make a Prefix Delegation (PD) request from your ISP over the connection to them: https://en.wikipedia.org/wiki/Prefix_delegation

This is Debian/Ubuntu specific, but the configuration file examples might help you: https://www.ipcalypse.ca/?p=204

---

Are you familiar with our Forum Rules, and How To Ask Questions The Smart Way?

BlueHackers // fscanary // resticctl

rsmarples

Member

Registered: 2009-05-12

Posts: 287

Re: IPv6 router

dhcpcd, in the Arch base system is also a DHCPv6 client and has extensive support for Prefix Delegation.