Bypass DNSSEC for local Stub zones
- by Starsky
I am using bind 9.9.2 as a DNSSEC validating recursive resolver in an Internet DMZ. I want to point to my internal DNS servers as stub zones (ideally) or anything except slave zones (to avoid very large zone transfers). We use a routable ip space for our Internal addressing. Sorry if I am using an IP space that you own in my example, but 167.x.x.x is the first zone I found that fits my issue.
E.G
dnssec-enable yes;
dnssec-validation yes;
dnssec-accept-expired no;
zone "16.172.in-addr.arpa" {
type stub;
masters { 167.255.1.53; }
}
zone "myzone.com" in {
type stub;
masters { 167.255.1.53; }
}
When queries hit the DNS server, they attempt at being validated, and fail because 167.in-addr.arpa HAS an RRSIG record, but sub zones do not (and should not!). Google dns is used in this example, but in reality it would be my recursive resolver.
@8.8.8.8 -x 167.255.1.53 +dnssec
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NXDOMAIN, id: 17488
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 0, AUTHORITY: 6, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags: do; udp: 512
;; QUESTION SECTION:
;53.1.255.167.in-addr.arpa. IN PTR
;; AUTHORITY SECTION:
167.in-addr.arpa. 1800 IN SOA z.arin.net. dns-ops.arin.net. 2013100713 1800 900 691200 10800
167.in-addr.arpa. 1800 IN RRSIG SOA 5 3 86400 20131017160124 20131007160124 812 167.in-addr.arpa. Lcl8sCps7LapnAj4n403KXx7A3GO7+2z/9Q2R2mwkh9FL26iDx7GlU4+ NufGd92IEJCdBu9IgcZP4I9QcKi8DI28og27WrfKd5moSl/STj02GliS qPTfNiewmTTIDw5++IlhITbp+CoJuZCRCdDbyWKmd5NSLcbskAwbCVlO vVA=
167.in-addr.arpa. 10800 IN NSEC 1.167.in-addr.arpa. NS SOA TXT RRSIG NSEC DNSKEY
167.in-addr.arpa. 10800 IN RRSIG NSEC 5 3 10800 20131017160124 20131007160124 812 167.in-addr.arpa. XALsd59i+XGvCIzjhTUFXcr11/M8prcaaPQ5yFSbvP9TzqjJ3wpizvH6 202MdrIWbsT1Dndri49lHKAXgBQ5OOsUmOh+eoRYR5okxRO4VLc5Tkze Gh0fQLcwGXPuv9A4SFNIrNyi3XU4Qvq0cViKXIuEGTa3C+zMPuvc0her oKk=
254.167.in-addr.arpa. 10800 IN NSEC 26.167.in-addr.arpa. NS RRSIG NSEC
254.167.in-addr.arpa. 10800 IN RRSIG NSEC 5 4 10800 20131017160124 20131007160124 812 167.in-addr.arpa. xnsLBTnPhdyABdvqtEHPxa6Y6NASfYAWfW1yYlNliTyV8TFeNOqewjwj nY43CWD77ftFDDQTLFEOPpV5vwmnUGYTRztK+kB5UrlflhPgiqYiBaBD RQaFQ8DIKaof8/snusZjK7aNmfe09t9gRcaX/pXn3liKz7m/ggxZi0f9 xo0=
;; Query time: 31 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Mon Oct 7 16:52:59 2013
;; MSG SIZE rcvd: 722
Is there a way to bypass DNSSEC validation for specific zones? Any zone that I host internally, I do not want DNSSEC validation performed on. I have only see this interfere w/ certain reverse zones where the top level has DS/RRSIG records.
Thanks.
