Lame delegation

A typical DNS misconfiguration
parent specifies a nameserver for a child domain
the server is not configured to have the authority
can easily happen since no automatic mechanism guarantees consistency
you'll see this in BIND log:
             info: lame server resolving 'foo.lame.example'
             (in 'lame.example'?): 192.0.2.3#53
"lame" servers tend to be left alone
other working nameservers can "hide" it
Why bad
make lookup slow
hit software bug in some cases
increase network traffic and server load
can be an "attack" for TLD servers