On Wed, 10 Jun 2015, George, Wes wrote:
On 6/10/15, 9:13 AM, "Baldur Norddahl" <baldur.nordd...@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/15-sy/dhcp-15-sy-book/ip6-dhcp-rel-agent.html#GUID-52D23F09-6829-4950-9431-92D9B7A255C0
"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: swm...@swm.pp.se
