From Newsgroup: comp.sys.raspberry-pi

Pancho <Pancho.Jones@protonmail.com> writes:

On 12/30/25 20:00, David Higton wrote:

In message <10iv40e$1e1ba$1@dont-email.me>
Pancho <Pancho.Jones@protonmail.com> wrote:

IPv6 seems like a world of pain.

In my experience it just works.

I'm surprised. Accepting that you do not do some of the things I do,
like policy routing rules based upon a host computer IP...

I actually do that. I route my IPTV boxes out via an alternate interface
due to some stupid contractual issues. So all I did was add routing
rules with ip -6 rule add from $addr table Magic and all the Magic table
has is a defaultroute out via the other interface. Same as IPv4. But
maybe your policy routing is something different?

For sure this would be a problem if the IPv6 addresses were changing all
the time but they haven't.
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From Newsgroup: comp.sys.raspberry-pi

On 14/01/2026 17:49, Anssi Saari wrote:

Pancho <Pancho.Jones@protonmail.com> writes:

On 12/30/25 20:00, David Higton wrote:

In message <10iv40e$1e1ba$1@dont-email.me>
Pancho <Pancho.Jones@protonmail.com> wrote:

IPv6 seems like a world of pain.

In my experience it just works.

I'm surprised. Accepting that you do not do some of the things I do,
like policy routing rules based upon a host computer IP...

I actually do that. I route my IPTV boxes out via an alternate interface
due to some stupid contractual issues. So all I did was add routing
rules with ip -6 rule add from $addr table Magic and all the Magic table
has is a defaultroute out via the other interface. Same as IPv4. But
maybe your policy routing is something different?

For sure this would be a problem if the IPv6 addresses were changing all
the time but they haven't.

Some routers will let you use the source mac address in routing rules
which nicely overcomes the problem with varying IPv6 addresses.

John

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From Newsgroup: comp.sys.raspberry-pi

On Wed, 14 Jan 2026 17:57:35 +0000, John R Walliker wrote:

Some routers will let you use the source mac address in routing rules
which nicely overcomes the problem with varying IPv6 addresses.

That could also be handled with a VLAN.
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: comp.sys.raspberry-pi

On 1/14/26 17:49, Anssi Saari wrote:

Pancho <Pancho.Jones@protonmail.com> writes:

On 12/30/25 20:00, David Higton wrote:

In message <10iv40e$1e1ba$1@dont-email.me>
Pancho <Pancho.Jones@protonmail.com> wrote:

IPv6 seems like a world of pain.

In my experience it just works.

I'm surprised. Accepting that you do not do some of the things I do,
like policy routing rules based upon a host computer IP...

I actually do that. I route my IPTV boxes out via an alternate interface
due to some stupid contractual issues. So all I did was add routing
rules with ip -6 rule add from $addr table Magic and all the Magic table
has is a defaultroute out via the other interface. Same as IPv4. But
maybe your policy routing is something different?

For sure this would be a problem if the IPv6 addresses were changing all
the time but they haven't.

Yes, that is the kind of thing but.. there was a bug in the pfSense
firewall rules. pfSense is a freeBSD firewall/router.

The bug was that pfSense allows you to predicate firewall rules on an
"alias", which can be a list of Full Qualified Domain Names. Something
like if the source host FQDN is in this alias, route over this gateway
to the WAN. The FQDNs resolve to an IPv4 and IPv6 addresses and then
checks the IP value in a packet and routes accordingly. This works fine
for a WAN FQDN, like e.g. www.google.com, it includes both IPv4 and IPv6 addresses. However, for hosts on my LAN, e.g. myhost.home.arpa if there
was an IPv4 address it gave only IPv4 and ignored the IPv6 one. I can
work around it by creating an extra FQDN for IPv6 e.g.
myhost.ipv6.home.arpa, but it takes time to understand why things don't
work.

Then there is the issue of the extra random IPv6 addresses it was
creating, which aren't included in DNS, in the FQDN at all.

That is the second IPv6 bug in pfSense, after the MTU/packet
fragmentation bug I mentioned earlier, which I'm still trying to get to
the bottom of.

IPv6 seems surprisingly hard. Surprising if a significant proportion of
people are using it.

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From Newsgroup: comp.sys.raspberry-pi

On Thu, 15 Jan 2026 01:17:23 +0000, Pancho wrote:

That is the second IPv6 bug in pfSense, after the MTU/packet
fragmentation bug I mentioned earlier, which I'm still trying to get
to the bottom of.

IPv6 seems surprisingly hard.

pfSense is built on FreeBSD and uses that network stack instead of
Linux, isn’t it?
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: comp.sys.raspberry-pi

On 1/14/26 21:13, Lawrence D’Oliveiro wrote:

On Wed, 14 Jan 2026 17:57:35 +0000, John R Walliker wrote:

Some routers will let you use the source mac address in routing rules
which nicely overcomes the problem with varying IPv6 addresses.

That could also be handled with a VLAN.

If your network hardware handles VLAN tags.

I have numerous switches (unmanaged) and WiFi access points, none of the
ones I tested were compatible with VLAN tags (i.e. The network device
stripped the VLAN tag off packets rather than dumbly passed the packet
through with VLAN tag intact).

VLANs also aren't ideal as you may wish to implement policy routing on a protocol (e.g. VoIP) or WAN destination, not just upon a LAN host.
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: comp.sys.raspberry-pi

On 1/15/26 05:10, Lawrence D’Oliveiro wrote:

On Thu, 15 Jan 2026 01:17:23 +0000, Pancho wrote:

That is the second IPv6 bug in pfSense, after the MTU/packet
fragmentation bug I mentioned earlier, which I'm still trying to get
to the bottom of.

IPv6 seems surprisingly hard.

pfSense is built on FreeBSD and uses that network stack instead of
Linux, isn’t it?

Yeah, I wasn't pointing out the bugs as directly relevant to Linux. I
was mentioning them to support my suspicions about a general lack of
maturity of IPv6 in products.
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: comp.sys.raspberry-pi

On 15/01/2026 13:33, Pancho wrote:

On 1/14/26 21:13, Lawrence D’Oliveiro wrote:

On Wed, 14 Jan 2026 17:57:35 +0000, John R Walliker wrote:

Some routers will let you use the source mac address in routing rules
which nicely overcomes the problem with varying IPv6 addresses.

That could also be handled with a VLAN.

If your network hardware handles VLAN tags.

I have numerous switches (unmanaged) and WiFi access points, none of the ones I tested were compatible with VLAN tags (i.e. The network device stripped the VLAN tag off packets rather than dumbly passed the packet through with VLAN tag intact).

VLANs also aren't ideal as you may wish to implement policy routing on a protocol (e.g. VoIP) or WAN destination, not just upon a LAN host.

There does seem to be a lot of variation in how different switches
behave. The HP 1820 and 1810 series web managed switches along with
a variety of Netgear web managed switches all propagate vlan tags in
their default state.
They can can be configured to detag vlans on specific ports if
necessary.
I have some Allied Telesis managed switches that block vlans by default.

John

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From Newsgroup: comp.sys.raspberry-pi

On Thu, 15 Jan 2026 13:33:44 +0000, Pancho wrote:

On 1/14/26 21:13, Lawrence D’Oliveiro wrote:

On Wed, 14 Jan 2026 17:57:35 +0000, John R Walliker wrote:

Some routers will let you use the source mac address in routing
rules which nicely overcomes the problem with varying IPv6
addresses.

That could also be handled with a VLAN.

If your network hardware handles VLAN tags.

I’m sure this could be done using a Linux box as your network
switch/router.
--- Synchronet 3.21a-Linux NewsLink 1.2

From Newsgroup: comp.sys.raspberry-pi

John R Walliker <jrwalliker@gmail.com> writes:

Some routers will let you use the source mac address in routing rules
which nicely overcomes the problem with varying IPv6 addresses.

Indeed. I wish I could do that easily in Linux but it seems a bit of a
chore. But looks like nftables packet marking and policy based routing
together can accomplish it. So all I need is the marking part and a
little tweaking of my policy routing to use those marks instead of
source IPv6 addresses.

Something to do later, I'm working on something else right now.

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