On 4/30/20 11:07 PM, Stuart Henderson wrote:
On 2020/04/30 20:32, Gerhard Roth wrote:
Hi Theo,
is umb really working that differently for a P2P interface? I think it is
very similar to ppp(4) and IPv6. The standard way is to obtain the IP
address via PPP protocol. Just like this, umb(4) obtains the IP address via
MBIM protocol.
PPP is quite different, it only negotiates a link-local v6 address. If you
want a routable address you must use slaac, dhcpv6, or static config.
That's what is implemented with this and former umb(4) patches. With the
current patch you can just do "ifconfig umb0 inet eui64" or "ifconfig umb0
-inet6" anytime, whether the interface is up or not.
But then there seem to be strange ISPs in Japan as detected by job@. They
don't provide any IPv6 address via MBIM protocol but rather use the standard
IPv6 SLAAC protocol. It strange; just as if ppp(4) would need DHCP to obtain
its IPv4 address. But still, it seems to exist and users can still work with
umb(4) if they do "ifconfig umb0 inet6 autoconf".
What happens if an ISP provides a v6 address via MBIM-config and the interface
is set to "inet6 autoconf", does it still work OK? That's what most people
will try. Since we disabled IPv6 by default, IPv6 users already know how to
use "inet6 autoconf".
I just can't tell. All providers here in Germany will give me an IPv6
address via MBIM. There's no way I could test this case. Especially not
in times of Corona.
Gerhard
I also feel noone is going to read the manual page, find this piece
of text, and understand it. Honestly, I don't understand this piece
of text. I'm not going to set the AUTOCONF6 flag. How does one even
set it?
ifconfig: AUTOCONF6: bad value
Of course not, but I am ironically trying to show this documentation
chunk doesn't help at all. People can't act upon it properly.
I still argue umb's inet6 should work absolutely as much like regular
interfaces, or it is useless. People are not going to treat this
interface differently and then gain successful inet6. If inet6 can't
work naturally and easily, but instead is a special snowflake, that
is just plain dumb.
Unfortunately mobile data is a special snowflake because you get some
providers who say "to conserve licenses with the network vendor you can
have either an IPv4 address or an IPv6 address but not both at the same
time" so you need a way to do something which isn't required on normal
ethernet.
+.Pp
+To use IPv6, configure a link-local address.
+If the device is able to connect to the ISP's network but doesn't
+show an IPv6 address, setting the
+.Sy AUTOCONF6
+flag on the interface before bringing it up may help.
+.Ed
Showing the actual command to type will help a lot here.
On 2020/04/30 20:52, Gerhard Roth wrote:
It it too much to expect users to read the ifconfig man page?
Printed, it is 28 pages of A4.
Compare with the wifi drivers, you have to look at ifconfig(8) if
you want all the details, but EXAMPLES in iwm(4) (and I think all the other
drivers) is enough for a quick bare-bones config. That seems a reasonable
model.
