PROBLEM_NO_REVERSE_MAPPING for entity

[regcom]

Hi,
I have this zone:

uniplan.it

$ORIGIN .
$TTL 3600 ; 1 hour
uniplan.it IN SOA uniserv.uniplan.it. admin.uniplan.it. (
2011101402
3600
1800
1209600
86400 )
$TTL 86400 ; 1 day
NS uniserv.uniplan.it.
NS uniserv1.uniplan.it.
NS webserver.uniplan.it.
$TTL 3600 ; 1 hour
A 217.20.0.2
MX 10 uniserv.uniplan.it.
$ORIGIN uniplan.it.
axis2100 A 217.20.0.15
board A 217.20.0.140
clessidra A 217.20.0.32
$ORIGIN clessidra.uniplan.it.
www A 217.20.0.32
$ORIGIN uniplan.it.
frattamaggiore A 85.44.177.45
$ORIGIN frattamaggiore.uniplan.it.
www A 85.44.177.45
$ORIGIN uniplan.it.
ftp CNAME uniserv
gargano A 217.20.0.73
$ORIGIN gargano.uniplan.it.
www A 217.20.0.73
$ORIGIN uniplan.it.
gesema.uniplan.it. IN A 85.33.176.119
$ORIGIN gesema.uniplan.it.

http://www.gesema.uniplan.it.

IN A 85.33.176.119
$ORIGIN uniplan.it.

http://www.gesemaeco

A 85.18.249.93
gm A 172.16.1.246
gm1mex A 172.16.80.61
gm2mex A 172.16.1.222
gm3mex A 172.16.1.222
localhost A 127.0.0.1
mailserver A 217.20.0.31
$ORIGIN mailserver.uniplan.it.
mailserver A 217.20.0.31
$TTL 86400 ; 1 day
$ORIGIN uniplan.it.
$TTL 3600 ; 1 hour
nt01 A 217.20.0.179
nt02 A 217.20.3.20
nt03 A 217.20.1.150
$TTL 86400 ; 1 day
ovi A 217.20.0.31
$TTL 3600 ; 1 hour
pomilia A 151.58.32.85
$ORIGIN pomilia.uniplan.it.
www A 151.58.32.85
$ORIGIN uniplan.it.
posta A 217.20.1.150
$ORIGIN posta.uniplan.it.
www A 217.20.1.150
$ORIGIN uniplan.it.
postfix A 217.20.0.76
radio A 217.20.0.73
$ORIGIN radio.uniplan.it.
www A 217.20.0.73
$ORIGIN uniplan.it.
rcis-01 A 217.20.0.1
rcis-02 A 217.20.0.14
rliv01-02 A 217.20.0.10
rliv02-02 A 217.20.0.13
rliv03-02 A 217.20.0.12
rliv04-02 A 217.20.0.11
sanmarcocavoti A 172.16.40.206
$ORIGIN sanmarcocavoti.uniplan.it.
www A 172.16.40.206
$ORIGIN uniplan.it.
spin0 A 217.20.1.8
spin1 A 217.20.3.3
spin2 A 217.20.3.2
spin3 A 217.20.3.103

http://www.radio.tanagro

A 85.44.172.158
$TTL 14400 ; 4 hours
uniplan TXT "v=spf1 a mx -all"
$TTL 3600 ; 1 hour
uniserv.uniplan.it. IN A 217.20.0.2
uniserv1.uniplan.it. IN A 217.20.0.3
watch02 A 217.20.0.176
watch03 A 217.20.0.177
weblinux A 217.20.0.72
webserver.uniplan.it. IN A 217.20.0.30
www CNAME uniserv
www4 A 217.20.0.73
gol.uniplan.it. IN A 217.20.1.150
mailserver-dns.uniplan.it. IN A 217.20.0.2
uniserv.uniplan.it. PTR 217.20.0.2
uniserv1.uniplan.it. PTR 217.20.0.3
webserver.uniplan.it. PTR 217.20.0.30

I have created this reverse zone:

217.20.0.

$ttl 38400
@ IN SOA uniserv.uniplan.it. system.uniplan.it. (
2011101403
10800
3600
604800
38400 )

2 IN NS uniserv.uniplan.it.
3 IN NS uniserv.uniplan.it.
30 IN NS uniserv.uniplan.it.

2 IN PTR uniserv.uniplan.it.
3 IN PTR uniserv1.uniplan.it.
30 IN PTR webserver.uniplan.it.

I have tested the zone with RIPE Zone Delegation Checker and I have this error:


>Check uniserv.uniplan.it details
PROBLEM_NO_REVERSE_MAPPING for entity uniserv.uniplan.it
>Args: 217.20.0.2, uniserv.uniplan.it
>Check uniserv1.uniplan.it details
PROBLEM_NO_REVERSE_MAPPING for entity uniserv1.uniplan.it
>Args: 217.20.0.3, uniserv1.uniplan.it
>Check webserver.uniplan.it details
PROBLEM_NO_REVERSE_MAPPING for entity webserver.uniplan.it
>Args: 217.20.0.30, webserver.uniplan.it


Can you help me to solve this error?

Thanks.