DHCP Reservations for IPv6 possible?

[Toad004]

I've got all my devices set with an IPv4 DHCP Reservation in the router's GUI.

Is there a way to do the same for IPv6? I know it's not in the GUI, but does merlin allow me to do this via editing the hosts or some config file via SSH? If so, what files would I need to edit and what code would I need to place?

Thank you for any help in advance.

 

[ZebMcKayhan]

I've got all my devices set with an IPv4 DHCP Reservation in the router's GUI.

Is there a way to do the same for IPv6? I know it's not in the GUI, but does merlin allow me to do this via editing the hosts or some config file via SSH? If so, what files would I need to edit and what code would I need to place?

Thank you for any help in advance.

Normally you would use stateless assignment for compatibility reasons (ipv6 tab). In this case router only assigns the first part of ipv6 (the prefix) and the device assigns itself the last part. In this case the router has no ability to assign a full static address.

If you where to use stateful it would be possible. Perhaps problematic for dynamic prefixes, and possible not via the gui, but possible.
However, some devices (like Android) are not compatible with this.

In general, for local communication you would use device ULA address, from within the same network. Or you just continue to use ipv4 or rely on mDNS.
For accessing services from internet each device should preferably create its own ddns record in I.e dynv6.

 

[Digilog]

I've got all my devices set with an IPv4 DHCP Reservation in the router's GUI.

Is there a way to do the same for IPv6? I know it's not in the GUI, but does merlin allow me to do this via editing the hosts or some config file via SSH? If so, what files would I need to edit and what code would I need to place?

Thank you for any help in advance.

Normally ipv6 DHCP just generate the prefix, then the device self assigns the rest of the address. Some of these servers can be configured for reservation of the whole ip address, but it will be derived from mac address of the device. Just depends on the IPv6 server.

So we would have to know what router and OS (if running pfsense, opensense, openwrt, ipfire, etc if not running the standard firmware). Because different versions of this server exists and some only can be set up this way by invoking a command at boot time while others require editing a configuration file.

Unless someone has fixed it, the drawback of assigning IPv6 addresses is that it breaks IPV6 dynamic routing. That is why it only generates a prefix and the devices are in a prefix pool.

 

[Toad004]

So we would have to know what router and OS (if running pfsense, opensense, openwrt, ipfire, etc if not running the standard firmware). Because different versions of this server exists and some only can be set up this way by invoking a command at boot time while others require editing a configuration file.

It is a GT-BE98 Pro, and as said previously, it's running merlin.

Unless someone has fixed it, the drawback of assigning IPv6 addresses is that it breaks IPV6 dynamic routing. That is why it only generates a prefix and the devices are in a prefix pool.

Is there a reason I should care about IPv6 dynamic routing on a home network with only one access point? (not intended to be sarcastic; I'm actually asking)

Some of the devices feel the need to take several IPv6 addresses, and one device in particular has over 80 (and climbing. This causes problems as some software insists on seeing each IPv6 Address as a separate device. I'd like to force them all to stick with just one.

 

[dave14305]

Some of the devices feel the need to take several IPv6 addresses, and one device in particular has over 80 (and climbing. This causes problems as some software insists on seeing each IPv6 Address as a separate device. I'd like to force them all to stick with just one.

This is usually a drawback of the method the router uses to detect these local IPv6 addresses. It doesn’t purge older obsolete addresses from its cache often enough. I use a startup script (init-start) to lower the cleanup threshold.

# For IPv6 address cleanup
if [ "$(nvram get ipv6_service)" = "dhcp6" ]; then
        echo 64 > /proc/sys/net/ipv6/neigh/default/gc_thresh1
fi