Hi, see below.
On 10 June 2013 22:48, Phil Pennock <[email protected]> wrote: >> On 2013-06-10 at 14:57 +0200, Dick Visser wrote: >>> This works for a while, but after a minute or so it changes back to the >>> default: >> >>> Any ideas what might be causing this? >> >>A thought, so only qualifies as "might", I don't know Windows to speak >>definitively, but ... IPv6 NDP Route Advertisement with the MTU option? >> >>Windows then updating the manually-configured value based upon learnt >>values on the wire? >Yup, this was the case. I watched it continuously, and when an RA came >in, it overwrote the manually configured MTU. >Next question: how do I prevent that from happening? Given that these systems are Windows Server 2008 R2, I would assume (and I can be wrong here) that you are configuring IPv6 related settings manually (address, gateway/dns etc.). One potential way _could_ be the deactivation of RA processing on these systems with the following command: "netsh int ipv6 set int [index] routerdiscovery=disabled". I don't know whether this is feasible in/for your environment, but (at least as of right now) it is the only solution which comes to my mind. I would also be interested whether this behavior you experienced is "working as intended" or could be considered a bug. Given that you mentioned that Windows 7 keeps the MTU value (haven't checked myself) I would (maybe naively) assume it is a bug. Will test this tomorrow with Windows 7 and Server 2008 R2. Cheers, Chris
