New to routing: what protocol do I need?

[Alessandro Vesely]

Hi, thank you!

I thought DHCPv6 was something similar to DHCP.  After some browsing, I hardly 
understand how can they be implemented by the same program.  I'll try and work 
out how to configure a DHCPv6 client which doesn't mess up with DNS and DHCPv4 
server...  When it works I'll send an answer to
https://unix.stackexchange.com/questions/742826/ipv6-over-pppoe
(unless someone else replies before me.)

Best
Ale


On Wed 26/Apr/2023 14:47:26 +0200 Arnaud Houdelette-Langlois wrote:
> Hi
> 
> The ISP-side router needs to know that it must route the /64s to your router.
>
> Most of the time this is done via DHCPv6/PD (PD stands for Prefix-Delegation). 
> You won't be able to do this with bird.
>
> Router advertisement do not do routing at all. It is just there to 
> auto-configure hosts.
>
> Arnaud Houdelette-Langlois
> Administrateur des infrastructures systèmes et réseaux
> Normandie Université
> +33 2 31 56 69 54
> 
> Le 26/04/2023 à 11:34, Alessandro Vesely a écrit :
>> On Tue 25/Apr/2023 19:12:13 +0200 Kevin P. Fleming wrote:
>>> On Tue, Apr 25, 2023, at 12:40, Alessandro Vesely wrote:
>>>> I don't know what protocol I need.  It is a new question.  I should know 
>>>> what protocol is using the next hop on ppp0 (default gw).  I'm not even 
>>>> sure what IPv6 hosts are out there; traceroute shows nothing.  Running 
>>>> traceroute from an external site I find that, wherever the trace starts 
>>>> from, it falls into a loop:
>>>
>>> It might be best to back up a bit here. Can you describe the scenario: what 
>>> is the network topology, and what requirements are placed on you by any 
>>> upstream or downstream networks? In addition to those, what are your goals 
>>> in using Bird?
>>
>>
>> I changed ISP, and they assigned me a /56 of IPv6 addresses.  My previous 
>> experience with IPv6 was using a tunnel offered by route48 for free.  In that 
>> case, I just plugged it in and it worked.  With my new ISP, I configured a 
>> couple of addresses on the interface (ppp0, they use PPPoE) but saw no IPv6 
>> traffic.  I opened a ticket at the ISP, they said something wrong on my side.
>>
>> I set up a /64 to use internally, and saw IPv6 works on the internal network. 
>> One internal user even managed to synthesize an IPv6 address in that range 
>> and connect to the server via WiFi. IPv6 on the lan is not a problem.
>>
>> I tried https://tools.keycdn.com/traceroute, and saw there is a loop. I had 
>> seen routing loops before, in IPv4, and they were usually errors in some 
>> static table somewhere.  My ISP repeated that everything is fine on their 
>> side.  So I derived I need some routing.
>>
>>
>>> Bird does not actually *route* traffic at all, please keep that in mind. It 
>>> is a routing table (FIB) manager, with a little bit of extra functionality 
>>> for IPv6 Router Advertisements and some other bits. It gathers route 
>>> information from a variety of sources, combines it together in the ways you 
>>> tell it to, and then publishes some (or all) of it to the destinations you 
>>> configure.
>>
>>
>> My understanding of radv is that it finds neighbors by itself. Should I 
>> configure any?  And can I check what hosts it found?
>>
>>
>>> Since it may not even be the right tool for the problem you are trying to 
>>> solve, it would be helpful if you could describe the problem first. With 
>>> that information the Bird user community can suggest ways Bird might be 
>>> applicable, if it is.
>>
>>
>> The main problem is that my addresses, e.g. 2a02:29e1:300:e900::1, are not 
>> reachable from the wan.  Symmetrically, I don't seem to be able to reach any 
>> external host on IPv6.  The only hint that the interface works at all on IPv6 
>> is that nmap says "Host is up." How can I get some visible reply from those 
>> hosts (2a02:29e1::a 2a02:29e0:109:ff00::5 2a02:29e0:255::2)?
>>
>>
>> Best
>> Ale
>>
>>
>>