Whole Archive: http://marc.info/?l=kvm&m=131609166918121&w=2 ----- Original Message ----- > On Thu, 2011-09-15 at 10:43 -0400, Amos Kong wrote: > > ----- Original Message ----- > > > ----- Original Message ----- > > > > On Thu, 15 Sep 2011 21:00:38 +0800, Amos Kong <akong@xxxxxxxxxx> > > > > wrote: > > > > > > > > > + netdev->xid = random(); > > > > > > > > This will not work for reboots. The decision that the hardware > > > > address > > > > is > > > > choosen was not accidental. Not sure if some DHCP server will > > > > count > > > > on > > > > the > > > > ID. (RFC 2131 "Retain DHCP client configuration across server > > > > reboots, > > > > and, > > > > whenever possible, a DHCP client should be assigned the same > > > > configuration > > > > parameters despite restarts of the DHCP mechanism"). If not so I > > > > am > > > > fine > > > > with the patch. > > > > Hi Hagen, > > > > rfc2131 clearly describes that we need a random xid, > > I don't think xid is a port of "DHCP client configuration", > > it only be used to associate messages and responses between client > > and server. > > > > I would post a patch to ipxe maillist later if it's ok. > > rfc2131 only required that "A DHCP client MUST choose 'xid's in such a > way as to minimize the chance of using an 'xid' identical to one used > by another client.". > > The 'random xid' suggestion is listed merely as an example. > > The way I see it using a xid based on MAC instead of a random number > is > safer since the odds for same MAC on the same network are pretty slim > since it would cause problems on other layers in the network. Users may boot up a QEMU guest without default mac address, it's easy to repeat. Yaniv, what real problem do you touched? only not in accordance to the RFC? Try to re-start host network, I can capture random dhcp idx, it's not fixed. Amos > Whats the reason behind this patch? Whats wrong with current selection > of xid? -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
