Date: Fri, 30 Aug 2019 12:15:43 +0900 (JST) From: Hiroki Sato <hrs@allbsd.org> To: vas@mpeks.tomsk.su Cc: freebsd-net@freebsd.org Subject: Re: Several IPv6 routers and default gateway choice Message-ID: <20190830.121543.1108900942284640156.hrs@allbsd.org> In-Reply-To: <20190830021228.GA66465@admin.sibptus.ru> References: <20190830021228.GA66465@admin.sibptus.ru>
next in thread | previous in thread | raw e-mail | index | archive | help
----Security_Multipart(Fri_Aug_30_12_15_43_2019_253)-- Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Victor Sudakov <vas@mpeks.tomsk.su> wrote in <20190830021228.GA66465@admin.sibptus.ru>: va> Dear Colleagues, va> va> If a FreeBSD host receives router advertisements from several IPv6 va> routers, on a LAN segment, which would be chosen as the default gateway? One reachable router will be selected based on the default router preference value in RA, which is defined in RFC 4191. If all of the routers have the same preference, the first one will win. va> Can this be used for failover? Yes. Another way to realize failover is to use a common anycast address on multiple routers. For example, a router is always able to have fe80::/64 as an anycast address like this: router# ifconfig igb0 inet6 fe80::/64 anycast and you can simply configure fe80::/64 as the default router on the hosts. Multiple routers with the same fe80::/64 can coexist on the same segment, and hosts will choose one of them with no further configuration. A caveat in this case is that the first router always wins and there is no knob to set the preferences across the routers with the same anycast address configured. -- Hiroki ----Security_Multipart(Fri_Aug_30_12_15_43_2019_253)-- Content-Type: application/pgp-signature Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- iMgEABMKAC0WIQRsDSNTJ8+Ax5Ae/dLbsH3Gbx9zfwUCXWiU3w8caHJzQGFsbGJz ZC5vcmcACgkQ27B9xm8fc3/TcAIIpMfBK171VP5Wr0/6zkFZo3liHRZWReklB/dY 5Ot4kIBkzuogJLAImvikDG2M7RAPQ2O9tu26iq5/+8dSWM7WsSsCCQHQUtZvtqKp XuRAfgfyru94ji3gdN0liAWdpkBxEMPlUgUsTlSVnA9s+JUKitChfAICvnEAbd6N WYsQrM4fLdEHbg== =qcBz -----END PGP SIGNATURE----- ----Security_Multipart(Fri_Aug_30_12_15_43_2019_253)----
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20190830.121543.1108900942284640156.hrs>