> > From: Brian E Carpenter <brian.e.carpen...@gmail.com> > > > I see no particular issue with a network where some LAG-aware routers > > do include the flow label in the hash and others don't. > > Any time you have a network which is using hop-by-hop path > selection (i.e. each node makes an independent decision on the > next hop) and those nodes are not all using i) the same > algorithm on ii) the same data, you can have routing loops.
In principle you're of course correct if the flow label was entered as a factor into the layer-3 routing computation, especially if individual routers do so differently. However, I don't think that would be the case in this specific example which is talking about a Link Aggregation Group (LAG). A LAG will from the layer-3 routing perspective appear as a single point-to-point path. So... what we're talking about is primarily a link-level forwarding decision, not a layer-3 routing decision. Thus, you can't get a routing loop, even if the devices at each end of the LAG would use different algorithms for distributing the load across the member links of the LAG. While I have your collective attention, I'll just say that I sometimes could wish for more focus on speedy deployment, and to seriously consider the time it takes from "tweak to a standard" until it's either initially deployed or even worse universally deployed in operational networks. To that end I'd like to commend the LISP designers for wanting to work with existing deployed hardware, and that I would turn my thumb down to those who seem to indicate they want to not to consider the already deployed base, and in effect go back to square zero. Best regards, - Håvard -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
