Security Unplugged Dns Cname Record Query Response This article describes an issue in which incorrect responses are received when an dns server uses wildcard cname and domain name system security extensions (dnssec) validation failures in windows server 2012 r2. an update is available to fix this issue. before you install this update, see the prerequisites section. "when a name server fails to find a desired rr in the resource set associated with the domain name, it checks to see if the resource set consists of a cname record with a matching class. if so, the name server includes the cname record in the response and restarts the query at the domain name specified in the data field of the cname record.
Security Unplugged Dns Cname Record Query Response I got no ip resolution if combining a cname with a wildcard record of type a (or aaaa). we tried the following: cliens try to resolve e.g.: node 1.app.global.tld ; the dns server (windows server 2019, recursive) has no zone information for app.global.tld. so, the query is forwarded and is responded with an cname e.g. node 1.app.something.tld. If a server is doing a recursion, asks for a record type that is not cname, but gets a cname response, then it should restart the query with the name from the cname record, merge the response from the restarted query with the cname response and return the combined response to whoever it was doing the recursion for. Cname rrs cause special action in dns software. when a name server fails to find a desired rr in the resource set associated with the domain name, it checks to see if the resource set consists of a cname record with a matching class. if so, the name server includes the cname record in the response and restarts the query at the domain name. Cloudflare will try to flatten the cname record considering both the specified dns view and any existing reference zones. if the reference zone then has another cname, the record will again be considered from the perspective of the original view. example. query for the a record on abc.example.local with view id 111.
Security Unplugged Dns Cname Record Query Response Cname rrs cause special action in dns software. when a name server fails to find a desired rr in the resource set associated with the domain name, it checks to see if the resource set consists of a cname record with a matching class. if so, the name server includes the cname record in the response and restarts the query at the domain name. Cloudflare will try to flatten the cname record considering both the specified dns view and any existing reference zones. if the reference zone then has another cname, the record will again be considered from the perspective of the original view. example. query for the a record on abc.example.local with view id 111. You may find issues if you have one of the following: the cname record you created for domain verification is set to proxied. the cname record is correctly set to dns only (not proxied), but your zone has flatten all cnames option enabled. make sure that: you have filled in the cname record fields correctly. the proxy status is set to dns only. When a name server fails to find a desired rr in the resource set associated with the domain name, it checks to see if the resource set consists of a cname record with a matching class. if so, the name server includes the cname record in the response and restarts the query at the domain name specified in the data field of the cname record. The unbound(dns resolvers) does not trust the glued record on the dns response, and will make a separate a record query against the cname. cnames are chased by unbound itself, asking the remote server for every name in the indirection chain, to protect the local cache from illegal indirect referenced items. If this lookup fails, the nameserver will check to see whether the record exists as a cname entry. when it finds it, the nameserver restarts the query using notfound.domain , which resolves to the ip xx.xx.xx.xx set for notfound.domain .
Dns Cname Resolution Record Response Networking Spiceworks Community You may find issues if you have one of the following: the cname record you created for domain verification is set to proxied. the cname record is correctly set to dns only (not proxied), but your zone has flatten all cnames option enabled. make sure that: you have filled in the cname record fields correctly. the proxy status is set to dns only. When a name server fails to find a desired rr in the resource set associated with the domain name, it checks to see if the resource set consists of a cname record with a matching class. if so, the name server includes the cname record in the response and restarts the query at the domain name specified in the data field of the cname record. The unbound(dns resolvers) does not trust the glued record on the dns response, and will make a separate a record query against the cname. cnames are chased by unbound itself, asking the remote server for every name in the indirection chain, to protect the local cache from illegal indirect referenced items. If this lookup fails, the nameserver will check to see whether the record exists as a cname entry. when it finds it, the nameserver restarts the query using notfound.domain , which resolves to the ip xx.xx.xx.xx set for notfound.domain .
Security Unplugged Dns A Record Query Response The unbound(dns resolvers) does not trust the glued record on the dns response, and will make a separate a record query against the cname. cnames are chased by unbound itself, asking the remote server for every name in the indirection chain, to protect the local cache from illegal indirect referenced items. If this lookup fails, the nameserver will check to see whether the record exists as a cname entry. when it finds it, the nameserver restarts the query using notfound.domain , which resolves to the ip xx.xx.xx.xx set for notfound.domain .