ubuntu：打开 udp 端口​​ 123

Question

进入我的linux服务器（Ubuntu 8），我已经为ntp打开了123端口。我已将其写入/etc/iptables.rules：

:INPUT ACCEPT [7496:9080183]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [4393:322232]
[0:0] -A INPUT -p udp -m udp --sport 8100 -j ACCEPT
[0:0] -A INPUT -p udp -m udp --dport 8100 -j ACCEPT
[0:0] -I INPUT -p udp --dport 123 -j ACCEPT
[0:0] -I OUTPUT -p udp --sport 123 -j ACCEPT
COMMIT

但是如果我启动这个命令：

nmap localhost -p123

回我：

Starting Nmap 4.53 ( http://insecure.org ) at 2013-03-28 12:05 CET
Interesting ports on localhost (127.0.0.1):
PORT    STATE  SERVICE
123/tcp closed ntp

如果我吃这个

ntpdate -d it.pool.ntp.org

回我：

28 Mar 11:07:31 ntpdate[5132]: ntpdate 4.2.4p4@1.1520-o Fri Dec  4 18:18:35 UTC 2009 (1)
transmit(212.45.144.59)
transmit(212.45.144.16)
transmit(2.228.72.62)
transmit(84.38.50.20)
transmit(212.45.144.59)
transmit(212.45.144.16)
transmit(2.228.72.62)
transmit(84.38.50.20)
transmit(212.45.144.59)
transmit(212.45.144.16)
transmit(2.228.72.62)
transmit(84.38.50.20)
transmit(212.45.144.59)
transmit(212.45.144.16)
transmit(2.228.72.62)
transmit(84.38.50.20)
transmit(212.45.144.59)
transmit(212.45.144.16)
transmit(2.228.72.62)
transmit(84.38.50.20)
212.45.144.59: Server dropped: no data
212.45.144.16: Server dropped: no data
2.228.72.62: Server dropped: no data
84.38.50.20: Server dropped: no data
server 212.45.144.59, port 123
stratum 0, precision 0, leap 00, trust 000
refid [212.45.144.59], delay 0.00000, dispersion 64.00000
transmitted 4, in filter 4
reference time:    00000000.00000000  Thu, Feb  7 2036  7:28:16.000
originate timestamp: 00000000.00000000  Thu, Feb  7 2036  7:28:16.000
transmit timestamp:  d4fe94e6.3e0589ac  Thu, Mar 28 2013 11:07:34.242
filter delay:  0.00000  0.00000  0.00000  0.00000
         0.00000  0.00000  0.00000  0.00000
filter offset: 0.000000 0.000000 0.000000 0.000000
         0.000000 0.000000 0.000000 0.000000
delay 0.00000, dispersion 64.00000
offset 0.000000

server 212.45.144.16, port 123
stratum 0, precision 0, leap 00, trust 000
refid [212.45.144.16], delay 0.00000, dispersion 64.00000
transmitted 4, in filter 4
reference time:    00000000.00000000  Thu, Feb  7 2036  7:28:16.000
originate timestamp: 00000000.00000000  Thu, Feb  7 2036  7:28:16.000
transmit timestamp:  d4fe94e6.7138de6d  Thu, Mar 28 2013 11:07:34.442
filter delay:  0.00000  0.00000  0.00000  0.00000
         0.00000  0.00000  0.00000  0.00000
filter offset: 0.000000 0.000000 0.000000 0.000000
         0.000000 0.000000 0.000000 0.000000
delay 0.00000, dispersion 64.00000
offset 0.000000

server 2.228.72.62, port 123
stratum 0, precision 0, leap 00, trust 000
refid [2.228.72.62], delay 0.00000, dispersion 64.00000
transmitted 4, in filter 4
reference time:    00000000.00000000  Thu, Feb  7 2036  7:28:16.000
originate timestamp: 00000000.00000000  Thu, Feb  7 2036  7:28:16.000
transmit timestamp:  d4fe94e6.a46f049a  Thu, Mar 28 2013 11:07:34.642
filter delay:  0.00000  0.00000  0.00000  0.00000
         0.00000  0.00000  0.00000  0.00000
filter offset: 0.000000 0.000000 0.000000 0.000000
         0.000000 0.000000 0.000000 0.000000
delay 0.00000, dispersion 64.00000
offset 0.000000

server 84.38.50.20, port 123
stratum 0, precision 0, leap 00, trust 000
refid [84.38.50.20], delay 0.00000, dispersion 64.00000
transmitted 4, in filter 4
reference time:    00000000.00000000  Thu, Feb  7 2036  7:28:16.000
originate timestamp: 00000000.00000000  Thu, Feb  7 2036  7:28:16.000
transmit timestamp:  d4fe94e6.d7a22706  Thu, Mar 28 2013 11:07:34.842
filter delay:  0.00000  0.00000  0.00000  0.00000
         0.00000  0.00000  0.00000  0.00000
filter offset: 0.000000 0.000000 0.000000 0.000000
         0.000000 0.000000 0.000000 0.000000
delay 0.00000, dispersion 64.00000
offset 0.000000

28 Mar 11:07:35 ntpdate[5132]: no server suitable for synchronization found

我必须重新启动某些东西还是我的配置有误？

Answer 1

ntp 是 udp 并且您正在扫描 tcp 这就是为什么它说它已关闭。

尝试这个

 nmap -sT -sU -p 123 localhost