On Tuesday, April 22, 2014, Henning Brauer <hb-nanog@bsws.de> wrote:
* Nick Hilliard <nick@foobar.org <javascript:;>> [2014-04-22 10:29]:
... turns 20 today.
This is the patent which covers hsrp, vrrp, many applications of carp and some other vendor-specific standby protocols.
it does NOT cover carp, not at all. carp was carefully designed to specifically avoid that.
CARP is a nonstandard protocol that was carefully designed to cause outages. Its authors submitted a slide deck describing their protocol instead of an internet-draft, which somehow managed to not get any traction in the IETF (funny that). The bar is pretty low for an informational RFC but the CARPheads couldn't be bothered. They threw a tantrum which involved camping out on the IETF's OUI (rather than getting their own) and deliberately choosing host bytes that conflict with the VRRP standard. This has the same predictable result as any duplicate MAC address, but since odds are it conflicts with a router, takes out the entire subnet instead of a single host. Of course this is not mentioned anywhere in CARP's documentation. That's why I encourage my competitors to run it. Drive slow, Paul