[Arm-dev] systemd-networkd and DHCP v6

Mon Jul 10 22:52:37 UTC 2017
Ian Pilcher <arequipeno at gmail.com>

Is anyone using the $SUBJECT combination?

I have a CentOS 7 (userland)/Banana Pi firewall, and I've been having an
issue where dhclient fails to renew my IPv6 address.  The root cause
seems to be that the initial lease is obtained before the B'Pi syncs its
system time, and ISC dhclient is unable to deal with large wall clock
changes:

   https://bugzilla.redhat.com/show_bug.cgi?id=1093803

(I haven't seen this problem with IPv4.  It seems like there's some sort
of workaround for this issue in the IPv4 case somewhere in the network
scripts, chrony, or dhclient itself.)

I just tried using systemd-networkd, instead of the legacy network
service, but it appears that systemd-networkd-219-30.el7.9.armv7hl will
never send a "dhcp6 solicit" packet, even when "DHCP=yes" (or
"DHCP=ipv6") is set in the relevant .network file.

I've verified with tcpdump that a RHEL 7 x86_64 VM *does* send a dhcp6
solicit, but there is absolutely no IPv6 UDP traffic coming from the
Banana Pi.

I'm back to the legacy network service for now, with a workaround to
forcibly renew the IPv6 lease once chrony has synced the time.  This is
my home firewall, so opportunity for messing around with the network
configuration is limited.

I am wondering, though, if anyone at all is using systemd-networkd with
DHCPv6 on CentOS 7 ARM?

-- 
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Ian Pilcher                                         arequipeno at gmail.com
-------- "I grew up before Mark Zuckerberg invented friendship" --------
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