[systemd-devel] Prefix Delegation, laking options in request.

Sat Mar 6 16:56:14 UTC 2021

Looks like the cable modem allocates itself a /60.  There are some
WiFi devices that grab a few /64(s), for some unknown reason.  There
should be at least one /63 if not a /62 available.  This is an
Espressobin, where I modified the device tree to rename the wan
interface.  All three ports connect to the same managed switch, where
link aggregation and trunking take place.

The following `dhcp6 solicit` seems to be missing PD flags, am I
wrong?  I'm `cheakoirccloud` on FreeNode's `#systemd` for chat.
Mailing list subscription disabled.
```
root at purgatory:~# tcpdump -i bond0 -n -vv '(udp port 546 or 547) or icmp6'&
root at purgatory:~# networkctl up xfinity
16:35:46.037253 IP6 (hlim 255, next-header ICMPv6 (58) payload length:
32) :: > ff02::1:ff71:de1c: [icmp6 sum ok] ICMP6, neighbor
solicitation, length 32, who has fe80::e066:d5ff:fe71:de1c
  unknown option (14), length 8 (1):
    0x0000:  7035 bc87 890f
16:35:47.064967 IP6 (flowlabel 0xc1dc5, hlim 1, next-header UDP (17)
payload length: 85) fe80::e066:d5ff:fe71:de1c.546 > ff02::1:2.547:
[bad udp cksum 0x90e2 -> 0x6186!] dhcp6 solicit (xid=c68004
(rapid-commit) (IA_NA IAID:957138656 T1:0 T2:0) (Client-FQDN)
(option-request DNS-server DNS-search-list NTP-server SNTP-servers
rapid-commit) (client-ID vid 0000ab11a3940e3f) (elapsed-time 0))
16:35:47.066654 IP6 (hlim 128, next-header UDP (17) payload length:
128) fe80::debf:e9ff:fefa:c2ab.547 > fe80::e066:d5ff:fe71:de1c.546:
[udp sum ok] dhcp6 reply (xid=c68004 (client-ID vid 0000ab11a3940e3f)
(IA_NA IAID:957138656 T1:132955 T2:199433 (IA_ADDR
2601:440:4101:97b0::1 pltime:265911 vltime:265911)) (DNS-server
2001:558:feed::1 2001:558:feed::2) (rapid-commit) (server-ID hwaddr
type 1 dcbfe9fac2ab))
16:35:47.740491 IP6 (flowlabel 0x65e26, hlim 255, next-header ICMPv6
(58) payload length: 16) fe80::e066:d5ff:fe71:de1c > ff02::2: [icmp6
sum ok] ICMP6, router solicitation, length 16
  source link-address option (1), length 8 (1): e2:66:d5:71:de:1c
    0x0000:  e266 d571 de1c
16:35:47.791128 IP6 (hlim 255, next-header ICMPv6 (58) payload length:
120) fe80::debf:e9ff:fefa:c2ab > ff02::1: [icmp6 sum ok] ICMP6, router
advertisement, length 120
hop limit 64, Flags [managed, other stateful], pref medium, router
lifetime 1800s, reachable time 0ms, retrans timer 0ms
  source link-address option (1), length 8 (1): dc:bf:e9:fa:c2:ab
    0x0000:  dcbf e9fa c2ab
  prefix info option (3), length 32 (4): 2601:440:4101:97b0::/64,
Flags [onlink, auto], valid time 345600s, pref. time 345600s
    0x0000:  40c0 0005 4600 0005 4600 0000 0000 2601
    0x0010:  0440 4101 97b0 0000 0000 0000 0000
  route info option (24), length 24 (3):  2601:440:4101:97b0::/60,
pref=medium, lifetime=265911s
    0x0000:  3c00 0004 0eb7 2601 0440 4101 97b0 0000
    0x0010:  0000 0000 0000
  rdnss option (25), length 40 (5):  lifetime 60s, addr:
2001:558:feed::1 addr: 2001:558:feed::2
    0x0000:  0000 0000 003c 2001 0558 feed 0000 0000
    0x0010:  0000 0000 0001 2001 0558 feed 0000 0000
    0x0020:  0000 0000 0002
16:35:47.836510 IP6 (flowlabel 0x74e47, hlim 255, next-header ICMPv6
(58) payload length: 32) fe80::172:dbbb:927e:24e6 > ff02::1: [icmp6
sum ok] ICMP6, neighbor advertisement, length 32, tgt is
2601:440:4101:97b0:e30b:4dfc:eee1:a624, Flags [override]
  destination link-address option (2), length 8 (1): b8:27:eb:d6:3a:c5
    0x0000:  b827 ebd6 3ac5
16:35:48.123254 IP6 (flowlabel 0xc1dc5, hlim 1, next-header UDP (17)
payload length: 85) fe80::e066:d5ff:fe71:de1c.546 > ff02::1:2.547:
[bad udp cksum 0x90e2 -> 0xf785!] dhcp6 solicit (xid=c68004
(rapid-commit) (IA_NA IAID:957138656 T1:0 T2:0) (Client-FQDN)
(option-request DNS-server DNS-search-list NTP-server SNTP-servers
rapid-commit) (client-ID vid 0000ab11a3940e3f) (elapsed-time 106))
16:35:48.125197 IP6 (hlim 128, next-header UDP (17) payload length:
128) fe80::debf:e9ff:fefa:c2ab.547 > fe80::e066:d5ff:fe71:de1c.546:
[udp sum ok] dhcp6 reply (xid=c68004 (client-ID vid 0000ab11a3940e3f)
(IA_NA IAID:957138656 T1:132955 T2:199433 (IA_ADDR
2601:440:4101:97b0::1 pltime:265911 vltime:265911)) (DNS-server
2001:558:feed::1 2001:558:feed::2) (rapid-commit) (server-ID hwaddr
type 1 dcbfe9fac2ab))
16:35:48.842561 IP6 (flowlabel 0x74e47, hlim 255, next-header ICMPv6
(58) payload length: 32) fe80::172:dbbb:927e:24e6 > ff02::1: [icmp6
sum ok] ICMP6, neighbor advertisement, length 32, tgt is
2601:440:4101:97b0:e30b:4dfc:eee1:a624, Flags [override]
  destination link-address option (2), length 8 (1): b8:27:eb:d6:3a:c5
    0x0000:  b827 ebd6 3ac5
ki16:35:49.844107 IP6 (flowlabel 0x74e47, hlim 255, next-header ICMPv6
(58) payload length: 32) fe80::172:dbbb:927e:24e6 > ff02::1: [icmp6
sum ok] ICMP6, neighbor advertisement, length 32, tgt is
2601:440:4101:97b0:e30b:4dfc:eee1:a624, Flags [override]
  destination link-address option (2), length 8 (1): b8:27:eb:d6:3a:c5
    0x0000:  b827 ebd6 3ac5
l16:35:50.132916 IP6 (flowlabel 0xc1dc5, hlim 1, next-header UDP (17)
payload length: 85) fe80::e066:d5ff:fe71:de1c.546 > ff02::1:2.547:
[bad udp cksum 0x90e2 -> 0x2f85!] dhcp6 solicit (xid=c68004
(rapid-commit) (IA_NA IAID:957138656 T1:0 T2:0) (Client-FQDN)
(option-request DNS-server DNS-search-list NTP-server SNTP-servers
rapid-commit) (client-ID vid 0000ab11a3940e3f) (elapsed-time 306))
16:35:50.134010 IP6 (hlim 128, next-header UDP (17) payload length:
128) fe80::debf:e9ff:fefa:c2ab.547 > fe80::e066:d5ff:fe71:de1c.546:
[udp sum ok] dhcp6 reply (xid=c68004 (client-ID vid 0000ab11a3940e3f)
(IA_NA IAID:957138656 T1:132955 T2:199433 (IA_ADDR
2601:440:4101:97b0::1 pltime:265911 vltime:265911)) (DNS-server
2001:558:feed::1 2001:558:feed::2) (rapid-commit) (server-ID hwaddr
type 1 dcbfe9fac2ab))
```

```
root at purgatory:/etc/systemd/network# head -n999 *
==> bond0.netdev <==
[NetDev]
Name=bond0
Kind=bond

[Bond]
Mode=802.3ad
TransmitHashPolicy=layer2
MIIMonitorSec=1s
LACPTransmitRate=fast

==> bond0.network <==
[Match]
Name=bond0

[Network]
VLAN=xfinity
VLAN=starlink
VLAN=sixteen
BindCarrier=eth0 lan0 lan1 lan2
LinkLocalAddressing=no

[Link]
RequiredForOnline=carrier

==> eth0.network <==
[Match]
Name=eth0

[Network]
LinkLocalAddressing=no
LLDP=no

==> home.netdev <==
[NetDev]
Name=home
Kind=bridge

==> home.network <==
[Match]
Name=home

[Network]
IPv6SendRA=Yes
DHCPv6PrefixDelegation=dhcpv6
IPv6DuplicateAddressDetection=1
IPv6PrivacyExtensions=No
LinkLocalAddressing=ipv6

[Address]
Address=10.64.4.1/22

==> lan0.network <==
[Match]
Name=lan0

[Network]
Bond=bond0
LinkLocalAddressing=no
LLDP=no

==> lan1.network <==
[Match]
Name=lan1

[Network]
Bond=bond0
LinkLocalAddressing=no
LLDP=no

==> lan2.network <==
[Match]
Name=lan2

[Network]
Bond=bond0
LinkLocalAddressing=no
LLDP=no

==> sixteen.netdev <==
[NetDev]
Name=sixteen
Kind=vlan

[VLAN]
Id=16

==> sixteen.network <==
[Match]
Name=sixteen

[Network]
Bridge=home
LinkLocalAddressing=no
LLDP=no

==> starlink.netdev <==
[NetDev]
Name=starlink
Kind=vlan

[VLAN]
Id=3

==> starlink.network <==
[Match]
Name=starlink

[Link]
RequiredForOnline=No

[Network]
DHCP=Yes

==> xfinity.netdev <==
[NetDev]
Name=xfinity
Kind=vlan

[VLAN]
Id=2

==> xfinity.network <==
[Match]
Name=xfinity

[Network]
DHCP=Yes
IPv6AcceptRA=Yes
IPv6DuplicateAddressDetection=1
IPv6PrivacyExtensions=kernel

[DHCPv6]
ForceDHCPv6PDOtherInformation=Yes
PrefixDelegationHint=2601:440:4101:97b4::/63
# PrefixDelegationHint=::/63
WithoutRA=solicit

[IPv6AcceptRA]
UseOnLinkPrefix=No
UseAutonomousPrefix=No
```

Thanks.