IPv6 manual PD

Peek · Sep 18, 2019, 1:50 PM

WAN interface is set to

PPPoE for IPv4 and
DHCP6 for IPv6.

DHCP6 client is set to

Request a IPv6 prefix/information through the IPv4 connectivity link
Only request an IPv6 prefix, do not request an IPv6 address
DHCPv6 Prefix - 56

Multiple VLANs (i.e. ADMIN & SERVERS) interfaces' IPv6 is set to

Track Interface with
IPv6 Interface pointed to WAN

IPv6 worked great and all was well for a few months... until the WAN link went down... being ongoing for 2 days already.

IPv6 machines, as registered within the DNS resolver cannot be reached as the IPv6 Prefix isn't presented due to the link being down. Though machines within the same VLAN can be reached via link-local (fe80::) addresses, this is a problem across VLANs.

What would be the most sane way to manually specify the IPv6 prefix in the interim, allowing at least internal access to all machines, whilst waiting for the WAN link to be restored ?

JKnott · Sep 18, 2019, 2:22 PM

@Peek said in IPv6 manual PD:

What would be the most sane way to manually specify the IPv6 prefix in the interim, allowing at least internal access to all machines, whilst waiting for the WAN link to be restored ?

I use Unique Local Addresses (ULA), in addition to the global ones. I have the ULA address listed in DNS.

Peek · Sep 19, 2019, 1:49 AM

@JKnott. Wasn't aware of ULA's until you mentioned it. Brilliant. Thanks.

It's thus as simple as defining an additional subnet under the RA per VLAN?

i.e.

fd00:: with prefix /64 on the 0 VLAN
fd10:: with prefix /64 on the 10 VLAN
fd20:: with prefix /64 on the 20 VLAN
etc ...

followed by a restart of pfsense.

Then adding the specific ULA's to the DNS resolver.

JKnott · Sep 19, 2019, 1:49 AM

@Peek

Yes, though a restart shouldn't be needed.

Peek · Sep 19, 2019, 2:51 AM

@JKnott ... reboot or no reboot, It's not working ...

I only get link-local (fe80::) addresses per interface.

Is DHCPv6 required ?

Peek · Sep 19, 2019, 3:26 AM

DHCPv6 not enabled.

RA set to Assisted.

Subnet to advertise added.

Rebooted pfsense. Unplugged & replugged switch. Still only getting link-local addresses.

Which memo didn't I get ?

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Derelict · Sep 19, 2019, 4:30 AM

What do you get if you set the interface IPv6 address to a static fd50::1/64 and use unmanaged mode?

Setting Assisted mode and disabling the DHCPv6 server doesn't make a lot of sense to me. If you only want SLAAC, use Unmanaged.

I'll just drop this here for the record since seeing fd50::/64 burns my eyes: https://tools.ietf.org/html/rfc4193#page-3

JeGr · Sep 19, 2019, 10:08 AM

@Derelict said in IPv6 manual PD:

I'll just drop this here for the record since seeing fd50::/64 burns my eyes: https://tools.ietf.org/html/rfc4193#page-3

Dito. Could use sth like this: https://cd34.com/rfc4193/

Derelict · Sep 19, 2019, 10:12 AM

$ randomlan
10.75.255.0
172.20.147.0
192.168.192.0
fdc5:eb06:dac6::/48

JKnott · Sep 19, 2019, 6:47 PM

@Peek said in IPv6 manual PD:

@JKnott ... reboot or no reboot, It's not working ...

I only get link-local (fe80::) addresses per interface.

Is DHCPv6 required ?

Assuming you're connect to an ISP that provided IPv6, you should get a valid prefix. You'd normally use DHCPv6-PD to connect to the ISP and the local LAN can use SLAAC or DHCPv6 to assign addresses to the devices.

Derelict · Sep 19, 2019, 6:42 PM

Does not need any cooperation or service from upstream.

Static ULA will work just fine locally.

JKnott · Sep 19, 2019, 6:48 PM

@Derelict said in IPv6 manual PD:

Does not need any cooperation or service from upstream.

Static ULA will work just fine locally.

I was thinking he should have both ULA and GUA. If he doesn't have either, there's some other problem.

Peek · Sep 20, 2019, 4:24 AM

@Derelict said in IPv6 manual PD:

What do you get if you set the interface IPv6 address to a static fd50::1/64 and use unmanaged mode?

Setting the IPv6 address statically unmanaged mode created a SLAAC with the prefix defines on a machine.

Setting Assisted mode and disabling the DHCPv6 server doesn't make a lot of sense to me. If you only want SLAAC, use Unmanaged.

Our broadband is still down and I'm a bit concerned about static IPv6's once we're receiving the ISP's PD again. Will it route correctly over pfsense and the VLANs when pfsense's IPv6 interface is not tracking the WAN interface anymore ?

I'll just drop this here for the record since seeing fd50::/64 burns my eyes: https://tools.ietf.org/html/rfc4193#page-3

I can understand the emphasis on a globally unique prefix with LUA (Local Unicast Addresses or is it ULA Unique Local Addresses) IPv6 addresses for larger multi-nationals. However, as it's not supposed to ever be globally routable, what would it break in small setups ?

As such, is

fd00::10: /64 for vlan 10
fd00::20: /64 for vlan 20
fd00::30: /64 for vlan 30
fd00::40: /64 for vlan 40
fd00::50: /64 for vlan 50

therefore a more acceptable approach ?

** Noted that the format above is seen as invalid in pfsense, though specifying fd00:0:0:50:: is acceptable **

Peek · Sep 20, 2019, 4:35 AM

@JKnott said in IPv6 manual PD:

Assuming you're connect to an ISP that provided IPv6, you should get a valid prefix. You'd normally use DHCPv6-PD to connect to the ISP and the local LAN can use SLAAC or DHCPv6 to assign addresses to the devices.

I am receiving a DHCPv6-PD from the ISP. The vLAN interfaces is then tracking the WAN interface and machines' interfaces is generally configured via SLAAC.

However, some machines (servers) have their IPv6 addresses statically assigned.

Once the broadband line went down, we cannot reach the machines unless using IPv4 due to the link-local addresses not being routeable over the VLANS.

I therefore need a ULA and GUA per interface, for when the PD isn't available for whatever reason. At present an interface is configured as follows:

# SLAAC
 iface eth0 inet6 auto

or

# DHCPv6
 iface eth0 inet6 dhcp

or

# Static 
 iface eth0 inet6 static
  address 2001:db8:3:4::8888
  netmask 64

How do I thus ensure an interface acquires both a GUA (via the ISP's PD) and a LUA (via pfsense) ... ?

Derelict · Sep 20, 2019, 4:55 AM

No. You will want to delete everything if you are getting a DHCP6 PD and using tracking interfaces.

What, exactly, is your goal.

When you deal with NATting IPsec connections because both sides chose the same RFC1918 subnet and nobody wants to renumber you will see the value of doing a globally-unique local /48 at every site from the beginning.

Peek · Sep 20, 2019, 5:04 AM

@Derelict said in IPv6 manual PD:

No. You will want to delete everything if you are getting a DHCP6 PD and using tracking interfaces.

Delete everything ... Sorry, I totally lost you there.

What, exactly, is your goal.

Local IPv6 addresses registered in the DNS resolver to allow contacting machines from the internal LAN when the Global prefix isn't being delegated.

When you deal with NATting IPsec connections because both sides chose the same RFC1918 subnet and nobody wants to renumber you will see the value of doing a globally-unique local /48 at every site from the beginning.

The idea is to move away from anything IPv4 related. IPv4 is only used as a backup and in some scenarios where IPv6 isn't fully supported.

Peek · Sep 20, 2019, 5:18 AM

@JKnott said in IPv6 manual PD:

I was thinking he should have both ULA and GUA. If he doesn't have either, there's some other problem.

Which is what I believe as well.

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Derelict · Sep 20, 2019, 5:37 AM

This post is deleted!

Derelict · Sep 20, 2019, 5:23 AM

There are problems with that.

https://redmine.pfsense.org/issues/5999

When I have to reboot I:

Delete the ULA IP Alias VIPs from LAN and DMZ
Edit/Save WAN to kick off DHCP6 and Track interface
Put the ULA VIPs back on LAN and DMZ

After that I am good until I have to reboot the firewall again. That is the current state of things. If that is unacceptable for you then pfSense, as it exists right now, might not be a good fit for your requirements.

$ ifconfig vlan0
vlan0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
	options=3<RXCSUM,TXCSUM>
	ether a8:60:b6:19:15:fe 
	inet6 fe80::18f3:9042:2cd0:8d8%vlan0 prefixlen 64 secured scopeid 0xd 
	inet6 2600:face:0ff:9501:ca2:7504:b2dc:4842 prefixlen 64 autoconf secured 
	inet6 2600:face:0ff:9501:b567:3b2f:300f:398c prefixlen 64 deprecated autoconf temporary 
	inet6 fd8c:9857:66db:1:4c9:e132:ee:396a prefixlen 64 autoconf secured 
	inet6 fd8c:9857:66db:1:10d2:3eb7:aefc:d655 prefixlen 64 deprecated autoconf temporary 
	inet 192.168.223.6 netmask 0xffffff00 broadcast 192.168.223.255
	inet6 2600:face:0ff:9501::145a prefixlen 64 dynamic 
	inet6 2600:face:0ff:9501:1123:95df:fb97:3e4c prefixlen 64 deprecated autoconf temporary 
	inet6 fd8c:9857:66db:1:1123:95df:fb97:3e4c prefixlen 64 deprecated autoconf temporary 
	inet6 2600:face:0ff:9501:b529:c61f:f4f5:ba3a prefixlen 64 deprecated autoconf temporary 
	inet6 fd8c:9857:66db:1:b529:c61f:f4f5:ba3a prefixlen 64 deprecated autoconf temporary 
	inet6 2600:face:0ff:9501:1dd:5877:4758:d9d2 prefixlen 64 deprecated autoconf temporary 
	inet6 fd8c:9857:66db:1:1dd:5877:4758:d9d2 prefixlen 64 deprecated autoconf temporary 
	inet6 2600:face:0ff:9501:551d:4e96:bb81:e2f7 prefixlen 64 deprecated autoconf temporary 
	inet6 fd8c:9857:66db:1:551d:4e96:bb81:e2f7 prefixlen 64 deprecated autoconf temporary 
	inet6 2600:face:0ff:9501:ecb6:32ad:85b6:8a8e prefixlen 64 deprecated autoconf temporary 
	inet6 fd8c:9857:66db:1:ecb6:32ad:85b6:8a8e prefixlen 64 deprecated autoconf temporary 
	inet6 2600:face:0ff:9501:3c69:b7aa:a84:284 prefixlen 64 autoconf temporary 
	inet6 fd8c:9857:66db:1:3c69:b7aa:a84:284 prefixlen 64 autoconf temporary 
	nd6 options=201<PERFORMNUD,DAD>
	vlan: 223 parent interface: en0
	media: autoselect (1000baseT <full-duplex>)
	status: active

Derelict · Sep 20, 2019, 5:30 AM

LAN:

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And:

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