Re: IP addressing + XO MPP connectivity
Hi John, On Tue, 2009-07-07 at 02:03 -0400, John Watlington wrote: >If you are getting a self-assigned IP address, it is > because the laptop is not discovering the MPP. > This is probably due to a short cut in the MPP > discovery process. The NM-0.6 code *definitely* ignores the IP address assigned from the MPP DHCP server. some snippets case MESH_S3_XO_MPP: /* Kill dhclient; we don't need it anymore after MPP discovery here * because we're ignoring the returned lease. */ nm_dhcp_manager_cancel_transaction (dhcp_manager, nm_device_get_iface (NM_DEVICE (self))); ... if (self->priv->step == MESH_S3_XO_MPP) { /* Step 3 (XO_MPP) ignores the IP address provided in the DHCP response, * so we still have to do autoip. */ if (!aipd_exec (self)) { nm_warning ("Activation (%s/mesh): couldn't start avahi-autoipd.", > The XS server software should set up any mesh interfaces > to accept the anycast MAC address, but this might have > been lost in more recent builds. The XS connectivity scenario is a totally different case, where the DHCP lease is indeed received and applied. The code differentiates between "school mesh" and "mesh portal" (and the anycast addresses are different). However I think you have indirectly explained why the MPP lease is ignored... you are accounting for the case where there are multiple MPPs all on 1 channel, therefore two MPPs could give the same IP address to 2 different XOs. autoipd presumably has some magic to avoid IP conflicts. And this is a pain to implement so it will probably not happen this time around... but I should be able to keep the school mesh case. Daniel ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: [Server-devel] IP addressing + XO MPP connectivity
On Tue, Jul 7, 2009 at 8:03 AM, John Watlington wrote: > The XS server software should set up any mesh interfaces > to accept the anycast MAC address, but this might have > been lost in more recent builds. Interesting. When was this last seen to work? I can do some quick archeology and resuscitate needed bits.. cheers, m -- martin.langh...@gmail.com mar...@laptop.org -- School Server Architect - ask interesting questions - don't get distracted with shiny stuff - working code first - http://wiki.laptop.org/go/User:Martinlanghoff ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
Re: IP addressing + XO MPP connectivity
Daniel, If you are getting a self-assigned IP address, it is because the laptop is not discovering the MPP. This is probably due to a short cut in the MPP discovery process. The original process was: - Discover the MPP by broadcasting an MPP discovery request using the MPP anycast MAC address. - All MPPs which receive the MPP discovery request would respond with a single packet. (This require route discovery to happen). - The firmware in the laptop's network interface only passes the MPP response packet from the "closest" MPP (using a metric of number of hops and the rates) up to the operating system. - The OS then addresses a DHCP request to the closest MPP's IP. (This requires route discovery to happen) - The DHCP server responds. - The laptop acknowledges the assignment. This resulted in a discovery process which took quite a bit of time. Combining the MPP discovery and the address assignment into a single step both sped up the process and eliminated the need for a separate mesh "discovery" daemon on the MPP. So the newer process was: - Discover a DHCP server (on a nearby MPP) by broadcasting a DHCP discovery using the anycast MAC address. - All MPPs which receive the DHCP discovery respond with a DHCP response. (This requires route discovery to happen) - The firmware in the laptop's network interface only passes the DHCP response from the "closest" MPP up to the OS. - The OS then addresses a DHCP request to the closest MPP. - The laptop acknowledges the assignment. The XS server software should set up any mesh interfaces to accept the anycast MAC address, but this might have been lost in more recent builds. Also, I believe there was a hack to the DHCP client on the laptop to make it issue the DHCP discovery request with the appropriate MAC destination address (instead of the broadcast MAC address.) Cheers, wad On Jul 6, 2009, at 12:41 PM, Daniel Drake wrote: > Hi, > > When connecting to a MPP-based mesh, the XO ignores the IP address > from > the MPP DHCP server and instead picks one using autoipd. Does anyone > know the motivation behind this? > > http://cgit.freedesktop.org/NetworkManager/NetworkManager/tree/src/ > nm-device-802-11-mesh-olpc.c?h=nm-0-6-olpc > > I'm working on reimplementing mesh support in NetworkManager-0.7; MPP- > or AA- based connectivity is still not supported but I'll reimplement > the client-side support if it's not too much hassle. (and this > particular bit may be hassle...) > > Daniel > > > ___ > Devel mailing list > Devel@lists.laptop.org > http://lists.laptop.org/listinfo/devel ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel
IP addressing + XO MPP connectivity
Hi, When connecting to a MPP-based mesh, the XO ignores the IP address from the MPP DHCP server and instead picks one using autoipd. Does anyone know the motivation behind this? http://cgit.freedesktop.org/NetworkManager/NetworkManager/tree/src/nm-device-802-11-mesh-olpc.c?h=nm-0-6-olpc I'm working on reimplementing mesh support in NetworkManager-0.7; MPP- or AA- based connectivity is still not supported but I'll reimplement the client-side support if it's not too much hassle. (and this particular bit may be hassle...) Daniel ___ Devel mailing list Devel@lists.laptop.org http://lists.laptop.org/listinfo/devel