From: Ben Pfaff Date: Wed, 16 May 2012 19:43:21 +0000 (-0700) Subject: PORTING: Add hint to adjust the default fail-mode, for hardware ports. X-Git-Tag: sliver-openvswitch-1.8.90-0~48^2~428 X-Git-Url: http://git.onelab.eu/?p=sliver-openvswitch.git;a=commitdiff_plain;h=4910bbc601abcd09f762426f5b7128a4bc6d379b PORTING: Add hint to adjust the default fail-mode, for hardware ports. Suggested-by: Rob Sherwood Signed-off-by: Ben Pfaff --- diff --git a/PORTING b/PORTING index 5281d50cf..ffde29637 100644 --- a/PORTING +++ b/PORTING @@ -245,6 +245,17 @@ ovs_be64 as fixed-width types in network byte order. Each of the latter is equivalent to the one of the former, but the difference in name makes the intended use obvious. +The default "fail-mode" for Open vSwitch bridges is "standalone", +meaning that, when the OpenFlow controllers cannot be contacted, Open +vSwitch acts as a regular MAC-learning switch. This works well in +virtualization environments where there is normally just one uplink +(either a single physical interface or a bond). In a more general +environment, it can create loops. So, if you are porting to a +general-purpose switch platform, you should consider changing the +default "fail-mode" to "secure", which does not behave this way. See +documentation for the "fail-mode" column in the Bridge table in +ovs-vswitchd.conf.db(5) for more information. + lib/entropy.c assumes that it can obtain high-quality random number seeds at startup by reading from /dev/urandom. You will need to modify it if this is not true on your platform.