Re: [dhcwg] I-D Action: draft-shen-dhc-client-port-01.txt

[Ted Lemon <[e-mail]>]

We went a fair distance down the relay agent chaining rathole a few years
ago:

https://tools.ietf.org/html/draft-lemon-dhcpv4-relay-encapsulation-01
https://tools.ietf.org/html/draft-kurapati-dhc-relay-chaining-dhcpv4-02

The effort was abandoned because IPv4...

On Fri, Jul 8, 2016 at 12:26 PM, Bernie Volz (volz) <[e-mail]> wrote:

> I don’t understand this at all. Unless you explicitly configured a Relay 2
> to always use port X when sending to Relay 1, where in the Packet from the
> Server (which comes from Relay 3) would Relay 2 know where to send the
> packet. You don’t want to have to have relay 2 remember this.
>
> - Bernie
>
> From: "Naiming Shen (naiming)" <[e-mail]>
> Date: Friday, July 8, 2016 at 3:23 PM
> To: Bernie Volz <[e-mail]>
> Cc: "[e-mail]" <[e-mail]>, "Enke Chen (enkechen)" <
> [e-mail]>
> Subject: Re: I-D Action: draft-shen-dhc-client-port-01.txt
>
>
> Hi,
>
> Thanks for the initial comment.
>
> We intend for this option to be hop-by-hop behavior instead of
> end-to-end. For example, in below DHCP devices topology:
>
> Client <—> Relay-1(x) <——> Relay-2(y) <—> Relay-3(z) <—> Server
>
> where (x, y, z) are the non-standard UDP source ports used by the
> relay agents of 1, 2 and 3.
>
> This DHCPv6 option is meant only between the two neighbors. When
> the Relay-2 receives from Relay-1, or the Relay-3 receives from Relay-2,
> or the Server receives from Relay-3, the implementation can easily
> setup the previous relay agent IPv6 address to the UDP port binding
> locally. When the reply message comes back in the other direction,
> the binding can be retrieved hop-by-hop, and optionally the binding
> can be discarded after.
>
> This restricts the issue between the two DHCPv6 neighbors and there
> is no state needs to be carried end-to-end for the DHCPv6 messages.
> This will also scale better if the relay cascading extend to N stages.
>
> thanks.
> - Naiming
>
> On Jul 8, 2016, at 12:04 PM, Bernie Volz (volz) <[e-mail]> wrote:
>
> Hi:
>
> Some initial comments:
>
> 1.       For DHCPv4, the zero length option can work since there is no
> provision for relay chaining.
> 2.       For DHCPv6, the zero length option does NOT work since this
> provides no means for a case where Relay 1 uses port X which is sent to
> Relay 2 which uses port Y to send to the Server. The server can response to
> Relay 2 on port Y (since that is the incoming port), but there is no place
> for Relay 2 to have stored the port. You should go back and make this
> option a 2 octet option with the port number. The server would then see:
> Relay-Forw from Relay 2
>                 Relay Port Source Port option Y
>                 Relay-Message option
>                                 Relay-Forw from Relay 1
>                                                 Relay Port source Port
> option X
>                                                 Relay- Message Option
>                                                                 <client’s
> request>
>                 And all would work correctly as the Server would use the
> port Y from the outermost relay option, relay 2 would use the port X from
> the Relay 1 Relay-Forw.
>
>
> -          Bernie
>
> *From:* dhcwg [mailto:[e-mail] <[e-mail]>] *On
> Behalf Of *Naiming Shen (naiming)
> *Sent:* Friday, July 08, 2016 12:29 AM
> *To:* [e-mail]
> *Subject:* [dhcwg] Fwd: I-D Action: draft-shen-dhc-client-port-01.txt
>
>
> Hi,
>
> We have updated the draft of “Generalized Source UDP Port of DHCP Relay”.
> Please review and comment.
>
> Thanks.
> - Naiming
>
>
> Begin forwarded message:
>
> *From: *[e-mail]
> *Subject: I-D Action: draft-shen-dhc-client-port-01.txt*
> *Date: *July 7, 2016 at 9:13:05 PM PDT
> *To: *<[e-mail]>
> *Reply-To: *[e-mail]
>
>
> A New Internet-Draft is available from the on-line Internet-Drafts
> directories.
>
>
>        Title           : Generalized Source UDP Port of DHCP Relay
>        Authors         : Naiming Shen
>                          Enke Chen
> Filename        : draft-shen-dhc-client-port-01.txt
> Pages           : 7
> Date            : 2016-07-07
>
> Abstract:
>   This document extends the DHCP and DHCPv6 protocols for the UDP
>   transport from relay agent to server and allows the port to be any
>   valid number on the DHCP relay system.
>
>
> The IETF datatracker status page for this draft is:
> https://datatracker.ietf.org/doc/draft-shen-dhc-client-port/
>
> There's also a htmlized version available at:
> https://tools.ietf.org/html/draft-shen-dhc-client-port-01
>
> A diff from the previous version is available at:
> https://www.ietf.org/rfcdiff?url2=draft-shen-dhc-client-port-01
>
>
> Please note that it may take a couple of minutes from the time of
> submission
> until the htmlized version and diff are available at tools.ietf.org.
>
> Internet-Drafts are also available by anonymous FTP at:
> ftp://ftp.ietf.org/internet-drafts/
>
> _______________________________________________
> I-D-Announce mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/i-d-announce
> Internet-Draft directories: http://www.ietf.org/shadow.html
> or ftp://ftp.ietf.org/ietf/1shadow-sites.txt
>
>
>
> _______________________________________________
> dhcwg mailing list
> [e-mail]
> https://www.ietf.org/mailman/listinfo/dhcwg
>
>