Re: [v6ops] DAD again [was: draft-ietf-v6ops-host-addr-availability discussion]

"Hemant Singh (shemant)" <shemant@cisco.com> Fri, 13 November 2015 12:31 UTC

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From: "Hemant Singh (shemant)" <shemant@cisco.com>
To: Lorenzo Colitti <lorenzo@google.com>, =?utf-8?B?56We5piO6YGU5ZOJ?= <jinmei@wide.ad.jp>
Thread-Topic: [v6ops] DAD again [was: draft-ietf-v6ops-host-addr-availability discussion]
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Date: Fri, 13 Nov 2015 12:31:24 +0000
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Subject: Re: [v6ops] DAD again [was: draft-ietf-v6ops-host-addr-availability discussion]
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From: v6ops [mailto:v6ops-bounces@ietf.org] On Behalf Of Lorenzo Colitti
Sent: Thursday, November 12, 2015 10:07 PM
To: 神明達哉
Cc: v6ops@ietf.org
Subject: Re: [v6ops] DAD again [was: draft-ietf-v6ops-host-addr-availability discussion]


>At most we could slightly amend this to ..."MUST be performed on all unicast addresses prior to assigning them to an interface except a loopback interface". Even node-internal interfaces are not >necessarily safe to omit DAD on. For example, in a mobile device the application processor and baseband processor might both be on the same link, and because they are two separate processors >running two separate network stacks, they need to do DAD.

Appendix A of RFC4862 already cautions against a loopback interface looping back DAD probes.  Did you have any other reason to disable DAD for a loopback interface?  For example, on a router, a loopback interface is configured and the IPv6 address on the interface is used to source packets.  Why would one not perform DAD for the IPv6 address used by the loopback interface?

Thanks,

Hemant