From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: passt.top; dmarc=none (p=none dis=none) header.from=gibson.dropbear.id.au Authentication-Results: passt.top; dkim=pass (2048-bit key; secure) header.d=gibson.dropbear.id.au header.i=@gibson.dropbear.id.au header.a=rsa-sha256 header.s=202510 header.b=OfL+KATm; dkim-atps=neutral Received: from mail.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by passt.top (Postfix) with ESMTPS id EBC715A026F for ; Fri, 10 Oct 2025 01:50:29 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=202510; t=1760053826; bh=YF43KFM5bOGk7VsET1gicnbEpQ2u0DAR0xUZSut6VZ0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OfL+KATmw7R2Zt2cj+Wf+RKKyXKWmEQHWSktR4Vlp2vNm1B6SDqUeEgS31/n/m3EL +oK0jBE0SMylAAEj/m0GyiL6VACAIHTiqPnCgsdFKGcmUtjnB7CSNjlUddFgnyGrX1 3HDh9My8xtcQoHxX5yn0P9cL8EtN7QXA6eP5riiO4Gjj7CBvyWr+47KpurImRwoWGZ yEqpxorCoKaLLHzwZdF3wOjIbUzKCVuMHE9ws4ZmoSzt7rKUYGj+8Focz6EBYgk2Op q9NbgLfAGcdE/U3xaMihS/K3aiGG0kw6yKJRMr2N2ue/QeKWgWJBMVWNGYC1yTkSVd DRaHY/Fj3wsjg== Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4cjRSy4rPWz4wBD; Fri, 10 Oct 2025 10:50:26 +1100 (AEDT) Date: Fri, 10 Oct 2025 10:46:22 +1100 From: David Gibson To: Stefano Brivio Subject: Re: [PATCH v12 3/9] arp/ndp: send ARP announcement / unsolicited NA when neigbour entry added Message-ID: References: <20251003003412.588801-1-jmaloy@redhat.com> <20251003003412.588801-4-jmaloy@redhat.com> <20251007121022.353a44fc@elisabeth> <20251008120118.046339db@elisabeth> <20251009212912.510f860e@elisabeth> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="lJSiY8BqJ+RrFl8M" Content-Disposition: inline In-Reply-To: <20251009212912.510f860e@elisabeth> Message-ID-Hash: 7LAW6CVYQH6QJZ23UOTK72YMRV3ZVWUG X-Message-ID-Hash: 7LAW6CVYQH6QJZ23UOTK72YMRV3ZVWUG X-MailFrom: dgibson@gandalf.ozlabs.org X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: Jon Maloy , dgibson@redhat.com, passt-dev@passt.top X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: --lJSiY8BqJ+RrFl8M Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Oct 09, 2025 at 09:29:12PM +0200, Stefano Brivio wrote: > On Thu, 9 Oct 2025 14:51:02 +1100 > David Gibson wrote: > > On Wed, Oct 08, 2025 at 12:01:18PM +0200, Stefano Brivio wrote: > > > On Wed, 8 Oct 2025 11:27:32 +1100 > > > David Gibson wrote: [snip] > > > but that wasn't the case, hence (I think) the > > > current struggle. If we go in that direction, I hope it's possible. = =20 > >=20 > > Thinking a bit more closely, I don't think it is, for much the same > > reason it wasn't in this draft. > >=20 > > According to the rules Jon and I thrashed out elsewhere in the thread, > > there are certain guest side addresses that must be locked to use > > our_tap_mac. We're essentially shadowing something that might exist > > on the host side, so we should use our MAC not the MAC of whatever is > > shadowed. > >=20 > > Just pre-populating an entry won't do the trick, because it could be > > overwritten if the right events occur for the shadowed host. >=20 > Right, sorry, I omitted another bit of context: I've been suggesting to > Jon that he'd introduce some kind of "permanent" or "administrative" > bit, and keep those entries at the beginning of the chain, exactly for > the reason you mention. Ah, right. Yes, that's a good idea. > I can imagine we'll need those at some point if we ever want to offer > explicit link-layer address mapping in the future, and they're probably > convenient the day one can change map_guest_addr and map_host_loopback > at runtime. >=20 > We can also happily skip that for the moment, though, it's another > problem we can keep for later. Right. --=20 David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson --lJSiY8BqJ+RrFl8M Content-Type: application/pgp-signature; name=signature.asc -----BEGIN PGP SIGNATURE----- iQIzBAEBCgAdFiEEO+dNsU4E3yXUXRK2zQJF27ox2GcFAmjoSUAACgkQzQJF27ox 2Gcuig/+JMO1iWXdM4e/V+KI3ndGn42Nvhz+K8E5xnHWlHwK9QKlGIzvXzLIAfqc sn84YSgZQLv/Hp6Us8v/2ALieBae2mgaF2lhAfz/TjNcXCq496y6KIvs9IIwzoCU 6C1T68F2RviSyQLT06fHPXIaIxVUMSTqgmpSVgudIu47kGsirfTbO49E2BU5spMa LEtftDD029bGb8r1dvNPF0ZDNv0dKcEobh9bg+XbGQgCwC16VMBWOAbruIVIuAk/ P1kkVyZtu3a2l04Cb5bQfmBqFYacr48Zvau8Bi/K+sQxY4r3yoxgbA7kP4pgChLL wrBrDRlAl4x3XLhsapoBLJC1QSaA/8cn/qfsfqTWI4o3w2ijtYEN4ImcvFKHTpGJ CBaOZ5OA5+pVcEipMvP89wcCDl7ULEthg8TU9L7kZF1ODQkH5h/hBxQCulcfNSdO qx7QCfIwmfFnKf6XTwujdUJACgL1ecmJjZeHILew/wOQ5LsbwoKhS6JJDBZWvnTj I1jDvMa0IYFVS38GNlx/nFv26rvXwYdtjTWR3rT1eBNDyWZ6IIBA5EJ0gh7Vm9Sn w+KWyqZs8uHVWq5EVXapr1SWnGAMG6LfPhSZvSiXcE7hzEa9pKxaRxiI6d9+bUEt 0DCySSs/84E4LdINOvGPakkSA5HTRuOIsRLX3Fs1pfp30HQLQzk= =PWvo -----END PGP SIGNATURE----- --lJSiY8BqJ+RrFl8M--