Question on DHCPv6 address assignment

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1

Folks,

I'm wondering about the following two aspects of different DHCPv6
implementations out there:

1) What's the pattern with which addresses are generated/assigned? Are
they sequential (fc00::1, fc00::2, etc.)? Random? Something else?

2) What about their stability? Is there any intent/mechanism for them to
be as "stable" as possible? Or is it usual for hosts to get a new
address for each lease?

P.S.: I understand this is likely to vary from one implementation to
another... so please describe which implementation/version you're
referring to.

Thanks!

Best regards,

2

Hi, Bill,

i in my bespoke version:

Is there any reference I could use for it?

1- psudo-random within a /32 space
2- not stable, unless coded to a fixed address

Regarding "2)", do you mean they are only stable if you ahve a MAC->IPv6
mapping "database", or something else?

Cheers,

3

Folks,

I'm wondering about the following two aspects of different DHCPv6
implementations out there:

1) What's the pattern with which addresses are generated/assigned? Are
they sequential (fc00::1, fc00::2, etc.)? Random? Something else?

Depends on your DHCPv6 server implementation. I believe ISC defaults to random. I’m not sure if that’s configurable or not.

2) What about their stability? Is there any intent/mechanism for them to
be as "stable" as possible? Or is it usual for hosts to get a new
address for each lease?

I believe they are generally stable in that once a DUID is associated with an address, that association is persistent, but that may also be implementation dependent.

P.S.: I understand this is likely to vary from one implementation to
another... so please describe which implementation/version you're
referring to.

I have limited experience with the ISC DHCPv6 server. Mostly I just use SLAAC.

Owen