Q: meaning of "bad referral" and "dangling CNAME pointer" log line.

Q: meaning of "bad referral" and "dangling CNAME pointer" log line.

Post by Ishikawa,Chiaki,remove No Spam from the addres » Sat, 13 Sep 1997 04:00:00

I have been running Bind 8.1.1 for about two months, and
enabled logging to understand the packet traffic, and capture
incorrect setup of ours and others.

1. Bad referral log line.

Such line is recorded like this.

BAD: Sep  9 18:06:03 sparc11 named[25625]: bad referral (156.239.202.in-addr.arpa !<

My log summarizer reported something like this.

bad referral

  6 times: (254.205.in-addr.arpa !< 167.254.205.in-addr.arpa)
  3 times: (254.205.in-addr.arpa !< 165.254.205.in-addr.arpa)
  2 times: (164.205.in-addr.arpa !< 68.164.205.in-addr.arpa)
  1 times: (jp !< laterra.or.jp)
  1 times: ( !< *.217.38.in-addr.arpa)
  1 times: (156.239.202.in-addr.arpa !<

Can anybody enlighten me on the meaning of the following construct?

        LHS !< RHS

!<  ... operator
LHS ... left-hand side
RHS ... right-hand side

2. Dangling CNAME pointer

Sample log line:

Sep 12 01:05:52 sparc20 named[423]: dangling CNAME pointer (

Does this  mean that the had
        - more than one-level of CNAME refernces before resolution to
          a real/existing entiry,
        - the reference that points to the original CNAME, or
        - the reference that points to non-existent DNS entity?

        AAA ---> BBB ---> CCC     (more than one indirection.)
        cname    cname    

        AAA ---> AAA (self reference?)
        cname    cname

        AAA ---> BBB ---> CCC ---> AAA (more than one indirection &
        cname    cname    cname         self-reference.)

        AAA ---> XXX (XXX being non-existent?)

        AAA ---> BBB ---> XXX
        cname    cname

Thank you in advance for your attention.

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