IPv6 setup with public subnet



  • So for some reason or another I cannot manage to get this to assign my computers IPv6 addresses via DHCP

    Went to the interface and set it to Static for IPv6
    Put the allocated address (XXXX:XXX:X:XX::X:2) with the /112 subnet that my ISP gave me.
    Then set the Gateway and assigned it (XXXX:XXX:X:XX::X:1)

    Then went to the home screen to make sure it said the IPv6 gateway was online. It was
    Then went to DHCPv6 ->Enabled it.
    I had set my range from XXXX:XXX:X:XX::X:10 - XXXX:XXX:X:XX::X:ffff
    prefix is empty
    delegation size is preselected to 64?
    Set the DNS servers to 2606:4700:4700::1111 - 2606:4700:4700::1001 - 2001:4860:4860::8888
    Then hit save.
    Then I went to Router Advertisements
    Router Mode - > Assisted
    everything else is left blank but at the bottom under DNS Configuration I had checked the box under "Settings" (Use same settings as DHCPv6 server).

    My windows box nor ubuntu box is getting an address.
    They are getting the proper IPv4 addresses.

    When I check my system logs I am seeing this.
    Under System->Routing

    Feb 6 00:52:26 radvd 24656 prefix length should be 64 for bridge0
    Feb 6 00:52:34 radvd 24656 our AdvValidLifetime on bridge0 for XXXX:XXX:X:XX::X:0 doesn't agree with fe80::72e4:22ff:fe7d:60e2
    Feb 6 00:52:34 radvd 24656 our AdvPreferredLifetime on bridge0 for XXXX:XXX:X:XX::X:0 doesn't agree with fe80::72e4:22ff:fe7d:60e2
    Feb 6 00:52:35 radvd 24656 prefix length should be 64 for bridge0

    Thank you in advanced for the help.



  • @demonmaestro

    A /112 is unusual. That only 65K addresses, too small for a LAN and much larger than typical for a point to point link. Are your addresses routed to you? Or just made available? Is there some reason you're using DHCPv6 instead of SLAAC?

    With my ISP, I get a /56 prefix via DHCPv6-PD. The WAN connection is a link local address with a /64 prefix and there is also a /128 WAN address. On the LAN side, I use SLAAC to provide the /64 prefix to devices and they create the their own suffix.



  • All I am seeing from what the ISP says is "This is a /112 assignment on my port." So I am guessing they are routed to me. Would SLAAC be better to use in this case?



  • @demonmaestro said in IPv6 setup with public subnet:

    "This is a /112 assignment on my port." So I am guessing they are routed to me.

    You can't assume that.

    Also, you'd use SLAAC on the LAN side, where you'd have a /64 prefix. While you could use DHCPv6, SLAAC is easier to set up.

    What ISP are you with? Maybe someone else here has experience with them.



  • I gave the ISP a shout and they are giving me a /64.
    Had to talk to some different people in the chain. I will look into the SLAAC.

    Thank you for the help.

    *edit: Had a space between m e.



  • @demonmaestro

    How are they providing that /64? Routed or just a block of address at the modem? A /64 you can get either way, but anything bigger requires routing. With my ISP, when my modem is in bridge mode, I get a /56 routed to me. However, in gateway mode, I just get a /64, which is not routed.



  • Just a block of IPs. I must configure the "router" to do what I want with them.


  • LAYER 8 Netgate

    IPv6 does not work like that. They should route at least a /56 to your WAN interface. You would then put a /64 on each inside interface. You would have 256 of those.



  • @Derelict unfortunately all they gave me was a /112. initially.
    Then today when I called them they said that they will give me a /64. But IF I want anything more than that that I would have to go directly to ARIN.



  • @demonmaestro said in IPv6 setup with public subnet:

    @Derelict unfortunately all they gave me was a /112. initially.
    Then today when I called them they said that they will give me a /64. But IF I want anything more than that that I would have to go directly to ARIN.

    Some ISPs are really pathetic. Many ISPs hand out /56s or even /48s, though I have heard of /60. These prefixes are routed, so they can be split into /64s by the customer's router. As I mentioned, a single /64 can be routed or not. You'll have to ask the ISP to find out. Also, what ISP are you with? Maybe someone else here has worked with them.


  • LAYER 8

    this is insane, a /48 could be assigned to every human in the world for the next 480 years before they run out. your isp will go out of business before that ...
    ask for at least a /56 if they don't want to give it to you, tell everywhere that this isp sucks and change it asap if you can



  • @kiokoman said in IPv6 setup with public subnet:

    this is insane, a /48 could be assigned to every human in the world for the next 480 years

    There are enough /48s to give every single person on earth over 4000 of them. This is with only 1/8 of the IPv6 address space assigned to GUAs. Over 3/4 of the address space isn't even allocated to anything.



  • @JKnott said in IPv6 setup with public subnet:

    There are enough /48s to give every single person on earth over 4000 of them. This is with only 1/8 of the IPv6 address space assigned to GUAs. Over 3/4 of the address space isn't even allocated to anything.

    <devils advocate>
    This is true, but it is not reflected in the price ARIN charges for v6 space. For a small provider, the annual fee doubles when you go from a /40 (256 customer allocations) to a /36 (4096 customer sites), and doubles again when you go to a /32 (65,536 sites). Probably smaller shops are trying to cut costs on v6 deployment, as it offers little benefit to them if they have sufficient v4 space.
    </devils advocate>


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