reverse ip zone delegation

[J.P.]

I've contacted att and had them set our reverse ip zone to be delegated
by our nameservers. I've done a trace with dig and it stops on att's
dns server and I don't understand why. Shouldn't it proceed to query
our nameservers and retrieve the ptr record? I could be totally off
since I am new to this. There is also one other bit of information that
bothers me with the CNAME att has setup. It contains a / as you will
see in the output below. I didn't think this was a valid character, but
again, I am new to this and I could be totally off.

Just as a side note, if I query out nameservers directly (local or
remote) using @ns... I get the expected information back.

Thanks,
J.P.

---

; <<>> DiG 9.2.4 <<>> +trace -x 12.96.12.250
;; global options:  printcmd
.                       517958  IN      NS      M.ROOT-SERVERS.NET.
.                       517958  IN      NS      A.ROOT-SERVERS.NET.
.                       517958  IN      NS      B.ROOT-SERVERS.NET.
.                       517958  IN      NS      C.ROOT-SERVERS.NET.
.                       517958  IN      NS      D.ROOT-SERVERS.NET.
.                       517958  IN      NS      E.ROOT-SERVERS.NET.
.                       517958  IN      NS      F.ROOT-SERVERS.NET.
.                       517958  IN      NS      G.ROOT-SERVERS.NET.
.                       517958  IN      NS      H.ROOT-SERVERS.NET.
.                       517958  IN      NS      I.ROOT-SERVERS.NET.
.                       517958  IN      NS      J.ROOT-SERVERS.NET.
.                       517958  IN      NS      K.ROOT-SERVERS.NET.
.                       517958  IN      NS      L.ROOT-SERVERS.NET.
;; Received 276 bytes from 64.29.16.113#53(64.29.16.113) in 32 ms

12.in-addr.arpa.        86400   IN      NS
CBRU.BR.NS.ELS-GMS.ATT.NET.
12.in-addr.arpa.        86400   IN      NS
CMTU.MT.NS.ELS-GMS.ATT.NET.
12.in-addr.arpa.        86400   IN      NS
DBRU.BR.NS.ELS-GMS.ATT.NET.
12.in-addr.arpa.        86400   IN      NS
DMTU.MT.NS.ELS-GMS.ATT.NET.
;; Received 143 bytes from 202.12.27.33#53(M.ROOT-SERVERS.NET) in 147
ms

250.12.96.12.in-addr.arpa. 172800 IN    CNAME
250.248/29.12.96.12.in-addr.arpa.
248/29.12.96.12.in-addr.arpa. 172800 IN NS      ns1.judelawfirm.com.
248/29.12.96.12.in-addr.arpa. 172800 IN NS      ns2.judelawfirm.com.
;; Received 140 bytes from
199.191.128.105#53(CBRU.BR.NS.ELS-GMS.ATT.NET) in 18 ms