Hi, On Sun, Sep 10, 2017 at 02:25:04PM +0300, Saku Ytti wrote: > On 10 September 2017 at 13:56, Thomas Bellman <[email protected]> wrote: > > > An alternative is to just have link-local addresses on your point-to- > > point links. At least on your internal links where you run your IGP. > > On external links, where you run eBGP or static routes, it's probably > > more trouble than it is worth, though, since link-local addresses can > > change if you replace the hardware, requiring a config change on the > > other end. (Also, I'm not sure all BGP implementations support using > > link-local addresses.)
all BGP implementations I'm aware of do that (support LLAs), BUT at least Cisco's doesn't support using the same LLAs in multiple BGP sessions (e.g. on PE-CE links) which in turn ruins the potential benefits in many environments, see https://ripe72.ripe.net/presentations/122-ERNW_RIPE72_IPv6wg_RFC7404.pdf https://blog.apnic.net/2016/05/31/beauty-ipv6-link-local-addressing-not/ > > This is solvable problem. Vendors support 'bgp listen' or 'bgp allow' > to accept BGP session from specific CIDR range. Similarly you could > allow IPv6 on interface, with SADDR anywhere in link-local. Your own > end link-local stability you could guarantee by manually configuring > MAC address, instead of using BIA. I.e. customers would experience > stable DADDR, but we wouldn't care about customer's SADDR. > > However I don't think market would generally appreciate the > implications linklocal brings to traceroute, where least bad option > would be just to originate hop-limit exceeded from loop0, with no > visibility on actual interface. some might be willing to accept that, as a trade-off for other benefits operations-wise. best Enno -- Enno Rey ERNW GmbH - Carl-Bosch-Str. 4 - 69115 Heidelberg - www.ernw.de Tel. +49 6221 480390 - Fax 6221 419008 - Cell +49 173 6745902 Handelsregister Mannheim: HRB 337135 Geschaeftsfuehrer: Matthias Luft, Enno Rey ======================================================= Blog: www.insinuator.net || Conference: www.troopers.de Twitter: @Enno_Insinuator =======================================================
