On Wed, 10 Jun 2015, George, Wes wrote:
On 6/10/15, 9:13 AM, "Baldur Norddahl" <baldur.norddahl@gmail.com> wrote:
What standard exactly requires my router to be able to snoop a DHCP-PD to create routes dynamically? That was left out and one solution is the one we use.
WG] We use this in cable-land, so it's definitely documented in the DOCSIS standards. Not sure it exists anywhere in the IETF standards, and so YMMV on which platforms do and do not support it.
http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipaddr_dhcp/configuration/1... "DHCPv6 Relay Agent Notification for Prefix Delegation The DHCPv6 relay agent notification for prefix delegation allows the device working as a DHCPv6 relay agent to find prefix delegation options by reviewing the contents of a DHCPv6 RELAY-REPLY packet that is relayed by the relay agent to the client. When a prefix delegation option is found by the relay agent, the relay agent extracts the information about the prefix that is being delegated and inserts an IPv6 static route matching the prefix delegation information onto the relay agent. Future packets destined to that prefix via relay will be forwarded based on the information contained in the prefix delegation. The IPv6 static route is then left in the routing table until the prefix delegation lease time expires or the relay agent receives a release packet from the client releasing the prefix delegation." I can't find IETF standards language apart from this: "14. Relay agent behavior A relay agent forwards messages containing Prefix Delegation options in the same way as described in section 20, "Relay Agent Behavior" of RFC 3315. If a delegating router communicates with a requesting router through a relay agent, the delegating router may need a protocol or other out-of-band communication to add routing information for delegated prefixes into the provider edge router."
From what I can find, a lot of vendors seem to have functionality implemented to look at the relayed messages and install static routes without any OOO-communication.
-- Mikael Abrahamsson email: swmike@swm.pp.se