Slave DNS không lấy được thông tin từ master DNS

Mình cài đặt 2 cái centos 6.4 trên virtual box như sau:
- Server:
Host name: masterdns.server.com
IP: 192.168.1.104
- Slave :
Host name: slavedns.server.com
IP: 192.168.1.105
Thế nhưng khi mình cấu hình xong thì mình không thấy masterdns truyền file qua cho slavedns. Dẫn đến slavedns khi mình chạy các lệnh dig hay nslookup đều không trả về kết quả như ý muốn. Masterdns dùng các lệnh dig hay nslookup thì ok. Đây là cách mình cấu hình:
Cấu hình cho cả 2 máy:
- Cả 2 máy mình đều đã cài các gói bind cần thiết (không cài bind-chroot để test thử trước đã)
- Cả 2 máy đều cấu hình iptables như sau:
Code:

# Generated by iptables-save v1.4.7 on Wed Aug  7 00:19:08 2013
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
-A INPUT -p udp -m multiport --dports 111,662,875,892,2049,32769 -j ACCEPT 
-A INPUT -p tcp -m multiport --dports 111,662,875,892,2049,32803 -j ACCEPT 
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT 
-A INPUT -p icmp -j ACCEPT 
-A INPUT -i lo -j ACCEPT 
-A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT 
-A INPUT -j REJECT --reject-with icmp-host-prohibited 
-A FORWARD -j REJECT --reject-with icmp-host-prohibited 

-A INPUT -p udp -m state --state NEW --dport 53 -j ACCEPT
-A INPUT -p tcp -m state --state NEW --dport 53 -j ACCEPT
-A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT

COMMIT
# Completed on Wed Aug  7 00:19:08 2013

- File /etc/resolv.conf
Code:

search server.com
name server 192.168.104
name server 192.168.105

- Ping cả 2 máy cho nhau đều được.

Thông tin mình setup DNS cho server:
File /etc/named.conf
Code:

options {
	listen-on port 53 { 127.0.0.1; 192.168.1.104;};		// Master DNS
	listen-on-v6 port 53 { ::1; };
	directory 	"/var/named";
	dump-file 	"/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";
        memstatistics-file "/var/named/data/named_mem_stats.txt";
	allow-query     { localhost; 192.168.1.0/24;};		// IP Range 
	allow-transfer	{ localhost; 192.168.1.105;};		// Slave DNS
	recursion yes;

	dnssec-enable yes;
	dnssec-validation yes;
	dnssec-lookaside auto;

	/* Path to ISC DLV key */
	bindkeys-file "/etc/named.iscdlv.key";

	managed-keys-directory "/var/named/dynamic";
};

logging {
        channel default_debug {
                file "data/named.run";
                severity dynamic;
        };
};

zone "." IN {
	type hint;
	file "named.ca";
};

zone "server.com" IN {
	type master;
	file "fwd.server.com";
	allow-update { 192.168.1.105; };
	allow-transfer { 192.168.1.105; };
};

zone "1.168.192.in-addr.arpa" IN {
	type master;
	file "rev.server.com";
	allow-update { 192.168.1.105; };
	allow-transfer { 192.168.1.105; };
};


include "/etc/named.rfc1912.zones";
include "/etc/named.root.key";

File /var/named/fwd.server.com
Code:

$TTL 1D
@		IN SOA	 	masterdns.server.com. root.server.com. (
					2013090802	; serial
					3600		; refresh
					1800		; retry
					604800		; expire
					86400 		; minimum
)
@		IN NS		masterdns.server.com.
@		IN NS		slavedns.server.com.
masterdns	IN A		192.168.1.104
		IN MX 1		mail.server.com.
slavedns	IN A		192.168.1.105
www		IN CNAME	masterdns.server.com.
mail		IN CNAME	masterdns.server.com.
ftp		IN CNAME	masterdns.server.com.
proxy		IN CNAME	masterdns.server.com.
itdep		IN NS		itdns.server.com.
itdns		IN A		192.168.1.106

File /var/named/rev.server.com
Code:

$TTL 1D
@		IN SOA	 	masterdns.server.com. root.server.com. (
					2013090802	; serial
					3600		; refresh
					1800		; retry
					604800		; expire
					86400 		; minimum
)
@		IN NS		masterdns.server.com.
@		IN NS		slavedns.server.com.
104		IN PTR		masterdns.server.com.
105		IN PTR		slavedns.server.com.
106		IN PTR		itdep.server.com.
		IN PTR		mail.itdep.server.com.

Cấu hình cho slave DNS:
File /etc/named.conf
Code:

options {
	listen-on port 53 { 127.0.0.1; 192.168.1.105;};
	listen-on-v6 port 53 { ::1; };
	directory 	"/var/named";
	dump-file 	"/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";
        memstatistics-file "/var/named/data/named_mem_stats.txt";
	allow-query     { localhost; };
	recursion yes;

	dnssec-enable yes;
	dnssec-validation yes;
	dnssec-lookaside auto;

	/* Path to ISC DLV key */
	bindkeys-file "/etc/named.iscdlv.key";

	managed-keys-directory "/var/named/dynamic";
};

logging {
        channel default_debug {
                file "data/named.run";
                severity dynamic;
        };
};

zone "." IN {
	type hint;
	file "named.ca";
};

zone "server.com" IN {
	type slave;
	file "fwd_slave.server.com";
	masters {192.168.1.104;};
};

zone "1.168.192.in-addr.arpa" IN {
	type slave;
	file "rev_slave.server.com";
	masters {192.168.1.104;};
};

include "/etc/named.rfc1912.zones";
include "/etc/named.root.key";

Thế nhưng mình vẫn không nhận được file từ serve truyền qua cho slave
Đây là file /var/log/messages của slavedns
Code:

Aug 11 09:50:26 slavedns named[3466]: zone 1.168.192.in-addr.arpa/IN: refresh: retry limit for master 192.168.1.104#53 exceeded (source 0.0.0.0#0)
Aug 11 09:50:26 slavedns named[3466]: zone 1.168.192.in-addr.arpa/IN: Transfer started.
Aug 11 09:50:26 slavedns named[3466]: transfer of '1.168.192.in-addr.arpa/IN' from 192.168.1.104#53: failed to connect: host unreachable
Aug 11 09:50:26 slavedns named[3466]: transfer of '1.168.192.in-addr.arpa/IN' from 192.168.1.104#53: Transfer completed: 0 messages, 0 records, 0 bytes, 0.001 secs (0 bytes/sec)
Aug 11 09:50:27 slavedns named[3466]: zone server.com/IN: refresh: retry limit for master 192.168.1.104#53 exceeded (source 0.0.0.0#0)