Re: IPv6 problems.... (dhcpcd weirdness, rshd fails, etc.)

[email protected] ("Greg A. Woods") writes:

>Nov 15 21:17:32 once inetd[10044]: connection from fe80::1030:c7e5:ac6d:b5ce%bge0(fe80::1030:c7e5:ac6d:b5ce%bge0), service shell (tcp6)
>Nov 15 21:17:32 once rshd[10044]: can't get stderr port: Can't assign requested address

Looks like a bug, the scope somehow gets lost and rshd cannot bind
to an unscoped link local address (the scope references the interface).

Nobody notices this with global IPv6 addresses.


>In looking for the cause of the rsh failure I also noted that dhcpcd is
>doing the following every 10 seconds:

>Nov 15 21:17:37 once dhcpcd[465]: bge0: requesting DHCPv6 information

It's trying to get usuable addresses via DHCPv6. This is triggered
by your router announcing a "managed" network prefix.



>For the record my router and firewall is a Netgear ORBI RBR50.  It's not
>so new any more and so maybe it's not doing something right.  There's
>not much to configure on it though.  My ISP has been providing IPv6
>globally routed addresses for some time now.

The router can be switched between IP address assignment via DHCP or
via AutoConfig. Maybe it doesn't announce a "managed" network with
the AutoConfig setting, but I doubt that.

Otherwise you can tell dhcpcd to not use DHCPv6 in the config file
("nodhcpv6").

Or you start using DHCPv6 instead of autoconfig.



>Also, after my apple-tv rebooted (after updating to tvOS 26), dhcpcd
>assigned another private net address to the interface (in fc00::/7,
>i.e. with an fd8d prefix).  That seems odd.  I didn't know the apple-tv
>could be running a DHCP server too!  My macos desktop also has an
>address in this same fd8d prefix, and it's listed as "autoconf secured".
>The macos ifconfig(8) doesn't say what "secured" means.

That's a "site local" address, Apple TV is known to announce such
a network as part of its HomeKit functionality when it boots without
a globally routed IPv6 network.

My guess is that "secured" means a private (random) address instead of
one derived from the MAC address.



>Tomorrow I might try my -current "daily" machine, but it's a domU
>running with an IPv4-only dom0 under it and I'm not sure if the
>bridge(6) and xvif(4) interfaces will be transparent to IPv6 traffic or
>not.

They are. Bridges work below the IP level.



Greetings,