How does MaraDNS respond to EDNS (RFC2671) packets?
MaraDNS 1.4 responds to EDNS packets by ignoring the OPT record and acting as if it the packet did not have an OPT record. Deadwood (the recursive resolver for Deadwood 2.0, available in the deadwood-#.#.## directory of any 1.4 MaraDNS release), up through Deadwood 2.9.02 responds to EDNS packets by discarding the packet and not responding. This was changed in Deadwood 2.9.03: Deadwood, as per RFC2671 section 5.3, now responds to EDNS queries by replying with the NOTIMPL (“not implemented”) error code instead of answering the query. This was changed again in Deadwood 2.9.04: Deadwood now, like MaraDNS 1 (as well as DJBdns), handles a EDNS packet as if the OPT record did not exist. MicroDNS (available in the tools/misc directory of any 1.4 MaraDNS release), as of MaraDNS 1.4.05, responds to EDNS queries the same way Deadwood 2.9.03 did: By giving back “NOTIMPL” instead of answering the query with the default IP. NanoDNS, in the interest of minimizing code side, responds to EDNS requests
