resolution problems due to timeouts on dig / servfail (aw-systems.net)

[Peter Davies]

Hi Florian,
    aw-systems.net appears to be delegated to the following name servers*:
  pns01.dcsix.net., pns02.dcsix.net., pns03.dcsix.net.m pns04.dcsix.net.

Resolving these named leads to a circular referral:
dcsix.net        NS -> pns01.kyberio-dns.com., pns02.kyberio-dns.de.
kyberio-dns.com. NS        -> gns01.edge-dns.com., gns02.edge-dns.com., 
gns03.edge-dns.de., gns04.edge-dns.de.
kyberio-dns.de.  NS -> gns01.edge-dns.com., gns02.edge-dns.com.
edge-dns.com.    NS -> pns01.kyberio-dns.com., pns02.kyberio-dns.de.
edge-dns.de.     NS -> pns01.kyberio-dns.com., pns02.kyberio-dns.de

*The TLD name servers include glue records in their referral:
;; AUTHORITY SECTION:
aw-systems.net.                172800        IN        NS pns01.dcsix.net.
aw-systems.net.                172800        IN        NS pns02.dcsix.net.
aw-systems.net.                172800        IN        NS pns03.dcsix.net.
aw-systems.net.                172800        IN        NS pns04.dcsix.net.

;; ADDITIONAL SECTION:
pns01.dcsix.net.        172800        IN        A 192.174.68.13
pns01.dcsix.net.        172800        IN        AAAA 2001:67c:1bc::13
pns02.dcsix.net.        172800        IN        A 176.97.158.13
pns02.dcsix.net.        172800        IN        AAAA 2001:67c:10b8::13
pns03.dcsix.net.        172800        IN        A 192.174.68.13
pns03.dcsix.net.        172800        IN        AAAA 2001:67c:1bc::13
pns04.dcsix.net.        172800        IN        A 176.97.158.13
pns04.dcsix.net.        172800        IN        AAAA 2001:67c:10b8::13

But these dcsix.net RR's are out of baliwick and are therefore not 
accepted by BIND

For more info regarding sibling glue checking, see:
      "Operational Notification: Impact of Stricter Glue Checking"
https://kb.isc.org/docs/strict-glue

/Peter

-- 
Peter Davies
Support Engineer
Internet Systems Corporation