Problem with resolver/host

[Doug Hardie]

> On 20 April 2021, at 14:12, Doug Hardie <bc979 at lafn.org> wrote:
> 
> I suspect this is an issue with the resolver, but it could also be in host.  I have the following in /etc/resolv.conf:
> 
> # Generated by resolvconf
> nameserver fe80::213:72ff:fec3:180f%bge0
> nameserver fe80::120c:6bff:fee9:cdf7%bge0
> 
> There is a DNS server running at the first address that supplies IPv6 addresses.  When I ping the first address, it succeeds:
> 
> test# ping fe80::213:72ff:fec3:180f%bge0
> PING6(56=40+8+8 bytes) fe80::6a5b:35ff:fed3:4eda%bge0 --> fe80::213:72ff:fec3:180f%bge0
> 16 bytes from fe80::213:72ff:fec3:180f%bge0, icmp_seq=0 hlim=64 time=0.321 ms
> 16 bytes from fe80::213:72ff:fec3:180f%bge0, icmp_seq=1 hlim=64 time=0.553 ms
> 16 bytes from fe80::213:72ff:fec3:180f%bge0, icmp_seq=2 hlim=64 time=0.544 ms
> 16 bytes from fe80::213:72ff:fec3:180f%bge0, icmp_seq=3 hlim=64 time=0.424 ms
> 
> However, host client.global.example return an error:
> 
> test# host client.global.example
> ;; connection timed out; no servers could be reached
> 
> ktrace of host shows that either host or the resolver is trying to use the address without the %bge0 which is why that error occurs:
> 
> 2027 host     STRU  struct sockaddr { AF_INET6, [fe80::213:72ff:fec3:180f]:53 }
>  2027 host     RET   sendto -1 errno 51 Network is unreachable
> 
> Is this a bug or is there some configuration item I have missed:
> 

I have filed a bug report: Bug 255316 on this.  However, it is still sitting in limbo:  

Assignee:	freebsd-bugs (Nobody)

I am not sure that the patch I provided is not going to break something else.  I am not sure this is the right place to ask these questions.  The resolver is used for more than just finding the default route.  I also have no idea how to build the parts needed to test it.  I know the patch works fine in a simple test case where I extracted that portion of the code as a standalone test.  I don't want to do a buildworld as that machine has no cooling and overheats quickly.  

-- Doug