问一个bind9转发的问题，区域转发总是无效

全局
forwarders { 58.20.127.170; };#联通dns
forward only;
recursion yes;

区域
zone "letv.com" {
forward only;
type forward;
forwarders { 59.51.78.211; }; ＃电信dns
};

zone "www.letv.com" {
forward only;
type forward;
forwarders { 59.51.78.211; }; ＃电信dns
};

我希望letv域转发到电信，但是结果总是联通的

[root@dns sbin]# nslookup letv.com
Server: 127.0.0.1
Address: 127.0.0.1#53

Non-authoritative answer:
Name: letv.com
Address: 115.182.94.238(电信地址)

--------------------------------------------------------------

[root@dns sbin]# nslookup www.letv.com
Server: 127.0.0.1
Address: 127.0.0.1#53

Non-authoritative answer:
www.letv.com canonical name = www.letv.com.cdn20.com.
www.letv.com.cdn20.com canonical name = letv.xdwscache.glb0.lxdns.com.
Name: letv.xdwscache.glb0.lxdns.com
Address: 119.36.195.228(联通地址)
Name: letv.xdwscache.glb0.lxdns.com
Address: 42.48.187.31(联通地址)

--------------------------------------------------------------

[root@dns ~]# dig @127.0.0.1 www.letv.com

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-20.P1.el5 <<>> @127.0.0.1 www.letv.com
; (1 server found)
;; global options: printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 26998
;; flags: qr rd ra; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.letv.com. IN A

;; ANSWER SECTION:
www.letv.com. 181 IN CNAME www.letv.com.cdn20.com.
www.letv.com.cdn20.com. 541 IN CNAME letv.xdwscache.glb0.lxdns.com.
letv.xdwscache.glb0.lxdns.com. 13 IN A 42.48.187.31
letv.xdwscache.glb0.lxdns.com. 13 IN A 119.36.195.228

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Sun Jan 26 21:48:04 2014
;; MSG SIZE rcvd: 135

[root@dns ~]# dig www.letv.com +trace

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-20.P1.el5 <<>> www.letv.com +trace
;; global options: printcmd
. 518400 IN NS B.ROOT-SERVERS.NET.
. 518400 IN NS E.ROOT-SERVERS.NET.
. 518400 IN NS K.ROOT-SERVERS.NET.
. 518400 IN NS J.ROOT-SERVERS.NET.
. 518400 IN NS F.ROOT-SERVERS.NET.
. 518400 IN NS L.ROOT-SERVERS.NET.
. 518400 IN NS M.ROOT-SERVERS.NET.
. 518400 IN NS G.ROOT-SERVERS.NET.
. 518400 IN NS A.ROOT-SERVERS.NET.
. 518400 IN NS H.ROOT-SERVERS.NET.
. 518400 IN NS C.ROOT-SERVERS.NET.
. 518400 IN NS D.ROOT-SERVERS.NET.
. 518400 IN NS I.ROOT-SERVERS.NET.
;; Received 348 bytes from 127.0.0.1#53(127.0.0.1) in 0 ms

com. 172800 IN NS m.gtld-servers.net.
com. 172800 IN NS i.gtld-servers.net.
com. 172800 IN NS j.gtld-servers.net.
com. 172800 IN NS g.gtld-servers.net.
com. 172800 IN NS l.gtld-servers.net.
com. 172800 IN NS b.gtld-servers.net.
com. 172800 IN NS h.gtld-servers.net.
com. 172800 IN NS a.gtld-servers.net.
com. 172800 IN NS k.gtld-servers.net.
com. 172800 IN NS d.gtld-servers.net.
com. 172800 IN NS e.gtld-servers.net.
com. 172800 IN NS f.gtld-servers.net.
com. 172800 IN NS c.gtld-servers.net.
;; Received 490 bytes from 192.228.79.201#53(B.ROOT-SERVERS.NET) in 238 ms

letv.com. 172800 IN NS ns1.leletv.com.
letv.com. 172800 IN NS ns3.leletv.com.
;; Received 105 bytes from 192.55.83.30#53(m.gtld-servers.net) in 222 ms

www.letv.com. 300 IN CNAME www.letv.com.cdn20.com.
;; Received 63 bytes from 123.126.33.193#53(ns3.leletv.com) in 57 ms

------------------------------------------------------

[root@dns sbin]# dig letv.com +trace

; <<>> DiG 9.3.6-P1-RedHat-9.3.6-20.P1.el5 <<>> letv.com +trace
;; global options: printcmd
. 518400 IN NS A.ROOT-SERVERS.NET.
. 518400 IN NS K.ROOT-SERVERS.NET.
. 518400 IN NS F.ROOT-SERVERS.NET.
. 518400 IN NS D.ROOT-SERVERS.NET.
. 518400 IN NS H.ROOT-SERVERS.NET.
. 518400 IN NS B.ROOT-SERVERS.NET.
. 518400 IN NS M.ROOT-SERVERS.NET.
. 518400 IN NS G.ROOT-SERVERS.NET.
. 518400 IN NS J.ROOT-SERVERS.NET.
. 518400 IN NS E.ROOT-SERVERS.NET.
. 518400 IN NS C.ROOT-SERVERS.NET.
. 518400 IN NS I.ROOT-SERVERS.NET.
. 518400 IN NS L.ROOT-SERVERS.NET.
;; Received 244 bytes from 127.0.0.1#53(127.0.0.1) in 0 ms

com. 172800 IN NS a.gtld-servers.net.
com. 172800 IN NS b.gtld-servers.net.
com. 172800 IN NS c.gtld-servers.net.
com. 172800 IN NS d.gtld-servers.net.
com. 172800 IN NS e.gtld-servers.net.
com. 172800 IN NS f.gtld-servers.net.
com. 172800 IN NS g.gtld-servers.net.
com. 172800 IN NS h.gtld-servers.net.
com. 172800 IN NS i.gtld-servers.net.
com. 172800 IN NS j.gtld-servers.net.
com. 172800 IN NS k.gtld-servers.net.
com. 172800 IN NS l.gtld-servers.net.
com. 172800 IN NS m.gtld-servers.net.
;; Received 486 bytes from 198.41.0.4#53(A.ROOT-SERVERS.NET) in 328 ms

letv.com. 172800 IN NS ns1.leletv.com.
letv.com. 172800 IN NS ns3.leletv.com.
;; Received 101 bytes from 192.5.6.30#53(a.gtld-servers.net) in 435 ms

letv.com. 600 IN A 115.182.94.238
letv.com. 86400 IN NS ns1.leletv.com.
letv.com. 86400 IN NS ns2.leletv.com.
letv.com. 86400 IN NS ns3.leletv.com.
;; Received 151 bytes from 123.126.33.193#53(ns3.leletv.com) in 56 ms