For reverse dns lookup

I created a reverse zone entry in named.conf:-

ipv6 address is :- 2a00:8a00:a000:11a1::a2b:1b91 and 2a00:8a00:a000:11a1::a2b:1b9f

zone "b.2.a.0.0.0.0.0.0.0.0.0.1.a.1.1.0.0.0.a.0.0.a.8.0.0.a.2.ip6.arpa" { type master; file "db.2a00:8a00:a000:11a1::a2b"; }; b.2.a.0.0.0.0.0.0.0.0.0.1.a.1.1.0.0.0.a.0.0.a.8.0.0.a.2.ip6.arpa

and created a reverse lookup file (db.2a00:8a00:a000:11a1::a2b) as below :-

$ORIGIN b.2.a.0.0.0.0.0.0.0.0.0.1.a.1.1.0.0.0.a.0.0.a.8.0.0.a.2.ip6.arpa $TTL 1h ; Default TTL @ IN SOA blrvse07vm03.oesblr.nsn-rdnet.net ( 2016050401 ; serial 1h ; slave refresh interval 15m ; slave retry interval 1w ; slave copy expire time 1h ; NXDOMAIN cache time )

; ; domain name servers ; @ IN NS blrvse07vm03.oesblr.nsn-rdnet.net. NS blrvse07vm03.oesblr.nsn-rdnet.net. NS blrvse07vm16.oesblr.nsn-rdnet.net.

; IPv6 PTR entries 1.9.b.1.b.2.a.0.0.0.0.0.0.0.0.0.1.a.1.1.0.0.0.a.0.0.a.8.0.0.a.2.ip6.arpa. IN PTR blrvse07vm03.oesblr.nsn-rdnet.net. f.9.b.1.b.2.a.0.0.0.0.0.0.0.0.0.1.a.1.1.0.0.0.a.0.0.a.8.0.0.a.2.ip6.arpa. IN PTR blrvse07vm17.oesblr.nsn-rdnet.

But reverse lookup is not working

host 2a00:8a00:a000:11a1::a2b:1b9f
Host f.9.b.1.b.2.a.0.0.0.0.0.0.0.0.0.1.a.1.1.0.0.0.a.0.0.a.8.0.0.a.2.ip6.arpa not found: 3(NXDOMAIN)

Please help.