In message <m1wale6-0000...@stereo.hq.phicoh.net>, Philip Homburg writes: > In your letter dated Wed, 16 Apr 2014 10:28:51 +1000 you wrote: > >There is already userland code that reacts to RA flags in FreeBSD > >to start dhcpv6. It's not hard to add yet another callback to > >stop/start dhcpv4. I suspect if I sat down to do this I could do > >code it in a day. This is not rocket science. I could do it from > >scratch with raw sockets in just about as much time. I just need > >to be able to see the RA's and know what interface they arrived on. > > Does that include all edge cases and the user interface? > > I.e. DHCPv4 has configured an address and by mistake a RA orders IPv4 to be > shutdown. Do you just shutdown IPv4? Does your code parse the output of > ifconfig to figure out if the interface was configured?
Yes. Why not as it been told it is allowed to shutdown IPv4 in the interface? > The user doesn't want this to happen on a production IPv4 network. Where in > the FreeBSD admin interface do you put the option to disable this behavior? Given we are taking about FreeBSD /etc/rc.conf it would be ifconfig_ed0_ranoipv4="NO" in there with the default in /etc/defaults/rc.conf ifconfig_ed0_ranoipv4="YES" possibly commented out. > An admin has stopped DHCPv4, now an RA comes along with the option to start > IPv4. Does your code just start DHPv4 or does it know that an admin took it > down? More correctly it was told to start IPv4 and yes. The admin should have temporarially disabled processing of the option if he didn't want ipv4 restarted. It is not uncommon for functions to auto start. If I fiddle with /etc/resolv.conf DHCP will re-write it on the next renew. This is similar. > Just a few the came to mind. I'm sure that when this is taken into production > there will be many more. And many confused admins who don't understand why > DHCPv4 is suddenly starting or stopping. Only because it is new. Once it is known about there won't be much confusion. > In contrast a DHCPNOSERVICE message that just suspends sending DHCPDISCOVER > messages for a while has almost no impact. It gets slightly trickier if > that also implies no link local, but not much. And doesn't achieve the intent of turning off IPv4 for the interface when you are not configuring using DHCP. Mark -- Mark Andrews, ISC 1 Seymour St., Dundas Valley, NSW 2117, Australia PHONE: +61 2 9871 4742 INTERNET: ma...@isc.org _______________________________________________ homenet mailing list homenet@ietf.org https://www.ietf.org/mailman/listinfo/homenet
