Re: DHCPv6 IA_PD - how-to

Roy Marples


 ---- On Wed, 31 Jul 2024 03:38:46 +0100  Karl Denninger  wrote --- 
 >     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

This all looks fine.

 > 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.

So if dhcpcd handles IPv6 RS in any way for form on any interface then it
will disable the kernel handling it. This is what you are seeing.
You should also disable rtsold.
On the other hand, you can leave the kernel handling everything RS by adding
noipv6rs
at the top of /etc/dhcpcd.conf

Is it possible you are using both?
Note that DHCPv6 will not set any default route, that's purely in the domain of RS.

Roy