Using an IPv4 switch in an IPv6 LAN

Installing and Using OpenWrt
1

Dear all,

I am migrating to IPv6 behind fiber, using an IPv6 tunnel (my provider does not offer IPv6).

My routeurs, servers, stations and LEDE appliances all support IPv6. But my main switch with 24 ports does not offer IPv4. The problem is that it interconnects all network, using VLAN. So it is a real bottleneck.

There are several technologies to encapsulate IPv6 in IPv4. At some point, I was able to ping6 from one host to another accross the IPv4 switch (or I have been dreaming?). But now I cannot connect and IPV6 routes are not exchanged.

What would be the best solution using LEDE to use this IPv4 switch in an IPv6 network? We probably are a lot of people with old but still good hardware switch (see my other project, migrating my switches to LEDE).

I read this interesting post on Debian WIKI:
https://wiki.debian.org/DebianIPv6#IPv6_Tunnel_Configuration

auto 6in4
iface 6in4 inet6 v4tunnel
address [Your IPv6 Endpoint]
netmask [Prefix Length]
endpoint [PoP IPv4 Endpoint]
gateway [PoP IPv6 Endpoint]
ttl 64
up ip link set mtu 1280 dev $IFACE

Can I use this technique to go through my IPv4 switch? By the way, a lot of recent switches sold "new" do not support IPv6. So it is a real issue to incorporate them in an IPv4 network.

Kind regards,
French Fries

2

Maybe I'm missing something but why would a switch care about the traffic flowing through it?
An ethernet frame is an ethernet frame is an ethernet frame, regardless of it being IPv4 or IPv6.
Now, any managament interface the switch might have is another matter altogether.
(I know this isn't a great answer but I'm offering it anyway in the odd chance I'm wrong and then learn something new)

3

Thanks. It makes sense to me.

4

Strictly speaking, a switch should be agnostic to the IP version, as @aboaboit pointed out. However, some switches incorporate functionality (like IGMP snooping, for example) that go beyond the strict functions of a switch, and might break in a IPv6 network.

1 Like
5

IPv6 now works like a charm, thanks!

1 Like