> But my point is that the OpenWrt router has no way to predict what > address/subnet will be assigned to its WAN port.
In principle, the ISP should assign either a global address, or an address in the range 100.64.0.0/10 (RFC 6598). This range was deliberately chosen to not collide with RFC 1918 space, so that the NAT box can choose any RFC 1918 prefix on its downstream interfaces. In practice, however, ISPs don't necessarily obey the RFCs, and people do chain NAT boxes, so none of the above is guaranteed. > Consequently, at boot-time, OpenWrt should simply choose some different > subnet for its LAN subnet(s), and then advertise an mDNS name. I'm not sure how that could happen at boot time, it would need to happen whenever a DHCPv4 lease changes. This implies that the router might need to renumber if the ISP changes its allocation, and there are no renumbering procedures for IPv4 (I'm not sure if anyone implements RFC 3203). It would also make addressing non-deterministic, which would make debugging slightly more difficult. But then, we already have non-deterministic addressing in IPv6, so I guess that's something we can live with. -- Juliusz _______________________________________________ Bloat mailing list Bloat@lists.bufferbloat.net https://lists.bufferbloat.net/listinfo/bloat
