Re: DHCPv6 IA_PD - how-to

From: Karl Denninger <karl_at_denninger.net>
Date: Wed, 31 Jul 2024 02:38:46 UTC
On 7/30/2024 16:54, Karl Denninger wrote:
> On 7/30/2024 10:44, Roy Marples wrote:
>> Don't use -T in the real world. It will exit once one address family completes.
>> You probably want the --noconfigure option.
>>
>> Roy
>
> Ah, ok.
>
> Well, next couple days I cannot screw with the network configuration 
> here as there are critical things that require I not do something I 
> may regret and might take a bit to reverse.... :-)
>
> However, I will attempt that as soon as I can (e.g. boot said machine 
> without external connectivity configured and see if "--noconfigure" 
> does what I'd expect it to do before turning it loose and maybe having 
> it make a mess.)
>
> Will advise when I can screw with the machine again -- note that I had 
> to use ia_na 1; omitting the index (presumably defaulting to zero) did 
> not return a delegation but did get the upstream route.  I DO like the 
> fact that I can have an exit hook setup that is "one script" that 
> handles both -- right now, with two programs, I have to deal with both 
> separately as there are things on that box that do have to be 
> reconfigured or at least restarted on an IP address change.
>
> --

I got a short window to play with this and have some odd results.

If I start it after booting it appears to work.  But on boot I get this 
during the boot sequence:


Starting dhcpcd.
dhcpcd-10.0.8 starting
igb0: link state changed to UP
igb1: link state changed to UP
no interfaces have a carrier
Additional TCP/IP options: IPv6 CPE WANIF=igb0.
Setting up harvesting: 
[CALLOUT],[UMA],[FS_ATIME],SWI,INTERRUPT,NET_NG,[NET_ETHE
R],NET_TUN,MOUSE,KEYBOARD,ATTACH,CACHED
Feeding entropy: dd: /boot/entropy: Read-only file system
.
igb0: link state changed to DOWN
Setting hostname: IpGw.Denninger.Net.
ELF ldconfig path: /lib /usr/lib /usr/local/lib /usr/local/lib/ipsec 
/usr/local/
lib/perl5/5.36/mach/CORE
32-bit compatibility ldconfig path: /usr/lib32 /usr/lib32
lo0: link state changed to UP
igb1: link state changed to DOWN
Starting Network: lo0 igb0 igb1 enc0.
igb0: link state changed to UP

Which would be ok EXCEPT all I get is an IPv4 address and its not 
repeatable either -- which it IS using DHCP provided by the system (that 
is, I RARELY get a different one -- with dhcpcd I ALWAYS get a different 
one.  I'd prefer not to; obviously if I must then I must, but it appears 
dhcpcd is not maintaining any sort of requested ID and thus even if the 
server CAN give me the same IP, it doesn't.)

But more troubling I don't get an IPv6 at all.  The reason appears to be 
that the default route doesn't get populated off the other end, and I 
note that "ACCEPT_RTADV" is NOT there -- and neither is 
"AUTO_LINKLOCAL".  If I stop it from /usr/local/etc/rc.d with "dhcpcd 
stop" and then "dhcpcd start" I *do* get the IPv6 delegation.

Gotta put it back on the other setup for now, but any ideas would be 
helpful - I can't take the connection offline for the next couple of 
days, but can work on it over the weekend.

-- 
Karl Denninger
karl@denninger.net
/The Market Ticker/
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