[ipxe-devel] Fallback to IPv4 or disable IPv6

[Geert Stappers]

On Mon, Nov 19, 2018 at 12:13:55PM +0100, Andreas Fink wrote:
> > On 19 Nov 2018, at 11:52, Michael Brown <mcb30 at ipxe.org> wrote:
> > On 01/11/2018 17:40, Anatoli Babenia wrote:
> >> My upstream provider doesn't support IPv6. No addresses are reachable.
> >> But my router still gives me an IPv6 address and is even able to resolve
> >> AAAA records. Being able to resolve IPv6 address iPXE thinks that it got
> >> IPv6 and fails, but it should try IPv4 instead.
> >> Here is the log - https://github.com/antonym/netboot.xyz/issues/283
> >> Is it possible to make current 133f fallback to IPv4 if IPv6 fetch fails?
> >> Also, is there an option to disable IPv6 from Failsafe Menu? Manual
> >> network configuration doesn't help.
> > 
> > iPXE will query for AAAA records only if the DNS server address is itself an IPv6 address.  This is the heuristic we use to decide between IPv6 and IPv4 when a DNS name is used.
> 
> This is not really what the idea is.
> 
> I would recommend the following logic:
 
I would appreciate patches.

> 1. If there is a IPv4 address only provided by the DHCP server, do IPv4 only.  Consider the host "ipv4 only"
> 1. If there is a IPv6 address only provided by the DHCP server or through router advertizement (and its not only link local)  do IPv6 only. Consider the host "ipv6 only"
> 3. If there host has a IPv4 and a IPv6 address do both ( Consider the host ipv4/ivp6 capable)

Bullshit.  Reread
> > iPXE will query for AAAA records only if the DNS server address is itself an IPv6 address.  This is the heuristic we use to decide between IPv6 and IPv4 when a DNS name is used.

Pay attention to the "decide between IPv6 and IPv4" part.


Cheers
Geert Stappers