New to routing: what protocol do I need?

[Alessandro Vesely]

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