Re: [dhcwg] recommendation on DHCP6 source port numbers

[David Farmer <[e-mail]>]

If we did, that would ensure DHCP messages will make it through typical
stateful firewalls without special rules.

Clients receive DHCP messages on UDP (destination) port 546.  Servers and
relay agents receive DHCP messages on UDP (destination) port 547.

Clients, servers, and relay agents SHOULD send DHCP messages from their
designated destination ports, as this will facilitate firewall traversal
for DHCP messages. Nevertheless, DHCP messages MUST be accepted from any
UDP (source) port, and regardless of the source port used, return DHCP
messages MUST be sent to their designated destination port.


On Thu, Feb 29, 2024 at 12:05 PM Ole Trøan <otroan=
[e-mail]> wrote:

> Should we also make it recommended to use the designated port as the
> source port? With the may to send arbitrary port and a must to accept an
> arbitrary port?
>
> O.
>
> On 29 Feb 2024, at 18:51, David Farmer <farmer=[e-mail]>
> wrote:
>
> 
> Ok, it's a little less wordy this time.
>
> Clients receive DHCP messages on UDP (destination) port 546.  Servers and
> relay agents receive DHCP messages on UDP (destination) port 547.
>
> Clients, servers, and relay agents MAY send DHCP messages from any UDP
> (source) port they are allowed to use, including their designated
> destination ports. Nevertheless, regardless of the source port used, DHCP
> messages MUST be sent to their designated destination ports.
>
> Thanks
>
> On Thu, Feb 29, 2024 at 10:24 AM David Farmer <[e-mail]> wrote:
>
>> Would this text clarify things?
>>
>> Clients receive DHCP messages on UDP (destination) port 546.  Servers and
>> relay agents receive DHCP messages on UDP (destination) port 547.
>>
>> Clients, servers, and relay agents MAY send DHCP messages from any UDP
>> (source) port they are allowed to use, including their designated
>> destination ports. Nevertheless, regardless of the source port the client
>> uses, the server or relay agent MUST send traffic to the designated
>> destination port of the client. And vice versa, regardless of the source
>> port used by the server or relay agent, the client MUST send traffic to the
>> designated destination port of the server or relay agent.
>>
>>
>> Thanks
>>
>> On Thu, Feb 29, 2024 at 10:03 AM Ole Troan <otroan=
>> [e-mail]> wrote:
>>
>>> Bernie,
>>>
>>> > DHCPv6 has been successfully deployed and this is the first I recall
>>> of this kind of discussion/issue.
>>> > You would likely also invalidate a lot of implementations with such a
>>> change, which is not really in line with advancing this to Full Standard.
>>>
>>> It’s a lot more important to have the specification clear and
>>> unambiguous. I think it has been shown that it isn’t.
>>> Happy with whatever solution there is consensus for, but the ambiguity
>>> has to be resolved I think.
>>>
>>> O.
>>> _______________________________________________
>>> dhcwg mailing list
>>> [e-mail]
>>> https://www.ietf.org/mailman/listinfo/dhcwg
>>>
>>
>>
>> --
>> ===============================================
>> David Farmer               Email:[e-mail]
>> Networking & Telecommunication Services
>> Office of Information Technology
>> University of Minnesota
>> 2218 University Ave SE        Phone: [phone]
>> Minneapolis, MN 55414-3029   Cell: 612-812-9952
>> ===============================================
>>
>
>
> --
> ===============================================
> David Farmer               Email:[e-mail]
> Networking & Telecommunication Services
> Office of Information Technology
> University of Minnesota
> 2218 University Ave SE        Phone: [phone]
> Minneapolis, MN 55414-3029   Cell: 612-812-9952
> ===============================================
>
>

-- 
===============================================
David Farmer               Email:[e-mail]
Networking & Telecommunication Services
Office of Information Technology
University of Minnesota
2218 University Ave SE        Phone: [phone]
Minneapolis, MN 55414-3029   Cell: 612-812-9952
===============================================