|
to Ted who offerred the text:
Relay agents do not maintain state. To return a message to its
source, the relay agent must include all the required information in
the Relay-Forward message. When a relay in a sequence of cascaded
relays does not use the standard source port, that source port must
be included along with the source address. This option allows the
relay agent to do so.
rfcdiff attached.
Cheers,
- Naiming
|
| draft-ietf-dhc-relay-port-05.txt | draft-ietf-dhc-relay-port-06.txt | |||
|---|---|---|---|---|
| Networking Working Group N. Shen | Networking Working Group N. Shen | |||
| Internet-Draft E. Chen | Internet-Draft E. Chen | |||
| Intended status: Standards Track Cisco Systems | Intended status: Standards Track Cisco Systems | |||
| Expires: October 27, 2017 April 25, 2017 | Expires: January 23, 2018 July 22, 2017 | |||
| Generalized UDP Source Port for DHCP Relay | Generalized UDP Source Port for DHCP Relay | |||
| draft-ietf-dhc-relay-port-05 | draft-ietf-dhc-relay-port-05 | |||
| Abstract | Abstract | |||
| This document proposes an extension to the DHCP protocols that allows | This document proposes an extension to the DHCP protocols that allows | |||
| a relay agent to receive packets from a server or an upstream relay | a relay agent to receive packets from a server or an upstream relay | |||
| agent on any UDP port, not just the default port 67 for IPv4 or | agent on any UDP port, not just the default port 67 for IPv4 or | |||
| default port 547 for IPv6. | default port 547 for IPv6. | |||
| skipping to change at page 1, line 33 | skipping to change at page 1, line 33 | |||
| Internet-Drafts are working documents of the Internet Engineering | Internet-Drafts are working documents of the Internet Engineering | |||
| Task Force (IETF). Note that other groups may also distribute | Task Force (IETF). Note that other groups may also distribute | |||
| working documents as Internet-Drafts. The list of current Internet- | working documents as Internet-Drafts. The list of current Internet- | |||
| Drafts is at http://datatracker.ietf.org/drafts/current/. | Drafts is at http://datatracker.ietf.org/drafts/current/. | |||
| Internet-Drafts are draft documents valid for a maximum of six months | Internet-Drafts are draft documents valid for a maximum of six months | |||
| and may be updated, replaced, or obsoleted by other documents at any | and may be updated, replaced, or obsoleted by other documents at any | |||
| time. It is inappropriate to use Internet-Drafts as reference | time. It is inappropriate to use Internet-Drafts as reference | |||
| material or to cite them other than as "work in progress." | material or to cite them other than as "work in progress." | |||
| This Internet-Draft will expire on October 27, 2017. | This Internet-Draft will expire on January 23, 2018. | |||
| Copyright Notice | Copyright Notice | |||
| Copyright (c) 2017 IETF Trust and the persons identified as the | Copyright (c) 2017 IETF Trust and the persons identified as the | |||
| document authors. All rights reserved. | document authors. All rights reserved. | |||
| This document is subject to BCP 78 and the IETF Trust's Legal | This document is subject to BCP 78 and the IETF Trust's Legal | |||
| Provisions Relating to IETF Documents | Provisions Relating to IETF Documents | |||
| (http://trustee.ietf.org/license-info) in effect on the date of | (http://trustee.ietf.org/license-info) in effect on the date of | |||
| publication of this document. Please review these documents | publication of this document. Please review these documents | |||
| skipping to change at page 4, line 38 | skipping to change at page 4, line 38 | |||
| paragraph. | paragraph. | |||
| A DHCP relay agent can listen for DHCP messages from a server or | A DHCP relay agent can listen for DHCP messages from a server or | |||
| another upstream relay agent device on any valid UDP port | another upstream relay agent device on any valid UDP port | |||
| available in the relay system including the DHCP UDP port 547. | available in the relay system including the DHCP UDP port 547. | |||
| The default UDP port is 547 if there is no explicit configuration | The default UDP port is 547 if there is no explicit configuration | |||
| for the generalized UDP source port extension for DHCP relay. | for the generalized UDP source port extension for DHCP relay. | |||
| 4. Relay Source Port Sub-option and Option | 4. Relay Source Port Sub-option and Option | |||
| Although a DHCP server can implicitly determine the UDP source port | Relay agents do not maintain state. To return a message to its | |||
| when it receives a message from a relay agent, this sub-option makes | source, the relay agent must include all the required information in | |||
| the request explicit for the server to use a non-DHCP UDP port in the | the Relay-Forward message. When a relay in a sequence of cascaded | |||
| reply message. When IPv6 cascaded relay agents are involved, the | relays does not use the standard source port, that source port must | |||
| downstream non-DHCP UDP port needs to be recorded using the option. | be included along with the source address. This option allows the | |||
| relay agent to do so. | ||||
| 4.1. Source Port Sub-option for DHCPv4 | 4.1. Source Port Sub-option for DHCPv4 | |||
| The Relay Agent "Source Port Sub-option" is a new option, and it is | The Relay Agent "Source Port Sub-option" is a new option, and it is | |||
| part of the relay-agent-information option for DHCPv4 [RFC3046]. | part of the relay-agent-information option for DHCPv4 [RFC3046]. | |||
| The format of the "Source Port Sub-option" is shown below: | The format of the "Source Port Sub-option" is shown below: | |||
| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | |||
| | SubOpt Code | Len | | | SubOpt Code | Len | | |||
| End of changes. 3 change blocks. | ||||
| 7 lines changed or deleted | 8 lines changed or added | |||
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