Clarification regarding dhcp.host.hostid with static leases

Installing and Using OpenWrt Network and Wireless Configuration
1

The wiki says about "dhcp.host.hostid":

The IPv6 interface identifier (address suffix) as hexadecimal number (max. 8 chars)

Also, this example of a static lease makes it pretty clear that the value determines the resulting assigned IPv6 address in combination with the delegated IPv6 prefix (if DHCPv6 is enabled, as opposed to e.g. SLAAC only).

Does anybody know the particulars about the expected value?
From "hexadecimal number" I assume that the value should be something like "aaaab123". Or "AAAAB123"? Does capitalization matter? The example only uses decimal digits.

Also, why does the wiki state "max. 8 chars"? This does not make sense to me, an IPv6 interface identifier may be up to 64 bit long, which equates to 16 hexadecimal digits, i.e. 16 characters.

2

@eomanis, welcome to the community!

Because -

8 * 8 == 64

I think you have a few misconceptions about what an "Interface ID" really is.

A lot of your misconceptions are clarified in that RFC.

3

Thanks for your reply.
Sure, but this is supposed to be hex, where 1 character encodes 4 bit. I think.

That RFC meshes well with my existing perception of an IPv6 Interface ID, which I would colloquially describe to be "the right half of an IPv6 address".