dhcpcd-discuss

On 07/11/2017 18:44, Neal P. Murphy wrote:
> Top posting as a quick response. I twerked the config (deleted the ra-own stuff, dropped the 1-year lease time, dropped the nohook, dropped the iaids for eth0-3], changed the eth3 iaid to '1', and changed the requested addr to ::/60. Results: it didn't actually add the addresses to eth[02], but did to eth3. It's better.
>
> I think I specified the iaids in order to 'force' them to known values. (I generally abhor computer-generated IDs; they're so abstract that only a computer can relate them to 'reality'.)
>
> Still get the autolink error; this is on the same kernel (3.4.109) that was OK before; oh, but I built for 3.16.49 which refuses to boot properly on my hardware, so yes, likely kernel headers. Should it be OK to run programs build with newer headers on an older kernel?

No :(
Going the other way is fine, older programs should work on newer 
kernels, but quite often newer programs don't work on older kernels.

For example, Linux-3.16 could define this

struct foo {
	char bar[32];
	int flags;
}
struct ofoo {
	int flags;
	char bar[32];
}
#define IOCTL_FOO 2
#define IOCTL_OFOO 1

whereas Linux-3.14 could define this

struct foo {
	int flags;
	char bar[32];
}
#define IOCTL_FOO 1


So something that uses foo when compiled on 3.14 works with 3.16 as well 
via a compat function, whereas the same program compiled for 3.16 won't 
work on 3.14

Now this is a very contrived example, but it gives hopefully some idea 
why what you're doing is a bad idea.

> I will try HEAD tonight and test more thoroughly. And send more detailed logs.

Please do, but I suspect you'll have the same issue.
Please build dhcpcd on 3.4.109 headers or older.
I don't understand why the /128 address was added fine though .....

Roy