dhcpcd-discuss

Hi folks,

I am using dhcpcd on an openBSD gateway to obtain a /64 and a /56 prefix
from Deutsche Telekom via pppoe, router advertisement and dhcpv6. The
/64 prefix is used for the connection between my gateway and  DT's gateway.
The /56 prefix is delegated to my Lan via dnsmasq.

Problem:

If I reset the pppoe connection, then the lease for the /56 prefix cannot
be reused. My gateway gets a new /56 prefix, but the old IPv6 address is not
removed from the internal NIC. dhcpcd assigns just a second address based
on the new prefix, confusing dnsmasq. I am not sure if this is correct.

Here is the syslog for a sample session:

Apr 20 13:27:35 marvin dhcpcd[98699]: DUID 00:01:00:01:20:79:21:d4:80:ee:73:95:c1:0c
Apr 20 13:27:35 marvin dhcpcd[98699]: pppoe0: IAID 00:00:00:00
Apr 20 13:27:35 marvin dhcpcd[98699]: pppoe0: rebinding prior DHCPv6 lease
Apr 20 13:27:35 marvin dhcpcd[98699]: re1: waiting for carrier
Apr 20 13:27:35 marvin dhcpcd[98699]: pppoe0: soliciting an IPv6 router
Apr 20 13:27:36 marvin dhcpcd[98699]: re1: carrier acquired
Apr 20 13:27:36 marvin dhcpcd[98699]: re1: IAID 73:95:c1:0d
Apr 20 13:27:37 marvin dhcpcd[98699]: pppoe0: Router Advertisement from fe80::101:101:3e9b:f1ab
Apr 20 13:27:37 marvin dhcpcd[98699]: pppoe0: adding address 2003:dd:b3bf:2325:665a:4ff:fe35:830a/64
Apr 20 13:27:45 marvin dhcpcd[98699]: pppoe0: failed to rebind prior delegation
Apr 20 13:27:45 marvin dhcpcd[98699]: pppoe0: soliciting a DHCPv6 lease
Apr 20 13:27:47 marvin dhcpcd[98699]: pppoe0: REPLY6 received from fe80::101:101:3e9b:f1ab
Apr 20 13:27:47 marvin dhcpcd[98699]: pppoe0: renew in 900, rebind in 1440, expire in 14400 seconds
Apr 20 13:27:47 marvin dhcpcd[98699]: lo0: adding reject route to 2003:dd:b3e3:2500::/56 via ::1
Apr 20 13:27:47 marvin dhcpcd[98699]: pppoe0: delegated prefix 2003:dd:b3e3:2500::/56
Apr 20 13:27:47 marvin dhcpcd[98699]: re1: adding address 2003:dd:b3e3:2500::1/56
Apr 20 13:27:47 marvin dhcpcd[98699]: re1: changing route to 2003:dd:b3e3:2500::/56
Apr 20 13:27:47 marvin dhcpcd[98699]: forked to background, child pid 46072
Apr 20 13:30:39 marvin dhcpcd[46072]: pppoe0: carrier lost
Apr 20 13:30:39 marvin dhcpcd[46072]: pppoe0: deleting address 2003:dd:b3bf:2325:665a:4ff:fe35:830a/64
Apr 20 13:30:39 marvin dhcpcd[46072]: pppoe0: if_addrflags: 93.233.206.36: Undefined error: 0
Apr 20 13:30:39 marvin dhcpcd[46072]: pppoe0: if_addrflags: Undefined error: 0
Apr 20 13:30:54 marvin dhcpcd[46072]: pppoe0: carrier acquired
Apr 20 13:30:54 marvin dhcpcd[46072]: pppoe0: IAID 00:00:00:00
Apr 20 13:30:54 marvin dhcpcd[46072]: pppoe0: rebinding prior DHCPv6 lease
Apr 20 13:30:54 marvin dhcpcd[46072]: pppoe0: Router Advertisement from fe80::101:101:3e9b:f1ab
Apr 20 13:30:54 marvin dhcpcd[46072]: pppoe0: adding address 2003:dd:b3bf:2336:665a:4ff:fe35:830a/64
Apr 20 13:31:04 marvin dhcpcd[46072]: pppoe0: failed to rebind prior delegation
Apr 20 13:31:04 marvin dhcpcd[46072]: pppoe0: soliciting a DHCPv6 lease
Apr 20 13:31:07 marvin dhcpcd[46072]: pppoe0: REPLY6 received from fe80::101:101:3e9b:f1ab
Apr 20 13:31:07 marvin dhcpcd[46072]: pppoe0: renew in 900, rebind in 1440, expire in 14400 seconds
Apr 20 13:31:07 marvin dhcpcd[46072]: lo0: adding reject route to 2003:dd:b3e3:3600::/56 via ::1
Apr 20 13:31:07 marvin dhcpcd[46072]: pppoe0: delegated prefix 2003:dd:b3e3:3600::/56
Apr 20 13:31:07 marvin dhcpcd[46072]: re1: adding address 2003:dd:b3e3:3600::1/56
Apr 20 13:31:07 marvin dhcpcd[46072]: re1: changing route to 2003:dd:b3e3:3600::/56
Apr 20 13:42:32 marvin dhcpcd[46072]: received SIGTERM, stopping
Apr 20 13:42:32 marvin dhcpcd[46072]: re1: removing interface
Apr 20 13:42:32 marvin dhcpcd[46072]: re1: deleting address 2003:dd:b3e3:2500::1/56
Apr 20 13:42:32 marvin dhcpcd[46072]: re1: deleting address 2003:dd:b3e3:3600::1/56
Apr 20 13:42:32 marvin dhcpcd[46072]: lo0: changing reject route to 2003:dd:b3e3:3600::/56 via ::1
Apr 20 13:42:32 marvin dhcpcd[46072]: re1: deleting route to 2003:dd:b3e3:2500::/56
Apr 20 13:42:32 marvin dhcpcd[46072]: pppoe0: removing interface
Apr 20 13:42:32 marvin dhcpcd[46072]: lo0: deleting reject route to 2003:dd:b3e3:3600::/56 via ::1
Apr 20 13:42:32 marvin dhcpcd[46072]: pppoe0: deleting address 2003:dd:b3bf:2336:665a:4ff:fe35:830a/64
Apr 20 13:42:32 marvin dhcpcd[46072]: dhcpcd exited


Look for "pppoe0: carrier lost" at 13:30:39, when I reset the pppoe0
interface. There is no "re1: deleting address ..." following, just
another IPv6 address assigned to re1. Both addresses have infinite
lifetime, but of course the old prefix is not routed anymore.

If I shutdown dhcpcd, then both addresses are deleted.

Here is my dhcpcd.conf:

ipv6only
# persistent
option rapid_commit
require dhcp_server_identifier
nohook lookup-hostname, resolv.conf
allowinterfaces re1 pppoe0
noipv6rs

interface pppoe0
        ipv6rs
        # static static domain_name_servers=<nameserver IPs>
        iaid 0
        ia_pd 0 re1/0


Every helpful comment is highly appreciated.

Harri