我全新安装了 Ubuntu 16.04。我使用以下说明配置了 iptables、ufw(使用 gufw)和 psad:https://www.thefanclub.co.za/how-to/how-secure-ubuntu-1604-lts-server-part-1-basics和https://www.thefanclub.co.za/how-to/how-install-psad-inrupt-detection-ubuntu-1204-lts-server。
一切似乎都运行良好,但现在我收到大量电子邮件,抱怨我的机器(对其自身)、我的路由器和网络上的其他设备进行 UDP 扫描。
我该如何解决这个问题?比如忽略他们之类的?
从服务器到其自身:
=-=-=-=-=-=-=-=-=-=-=-= Tue May 3 18:40:47 2016 =-=-=-=-=-=-=-=-=-=-=-=
Danger level: [2] (out of 5)
Scanned UDP ports: [32412-32414: 6 packets, Nmap: -sU]
iptables chain: INPUT (prefix "[UFW AUDIT]"), 2 packets
iptables chain: OUTPUT (prefix "[UFW ALLOW]"), 2 packets
iptables chain: OUTPUT (prefix "[UFW AUDIT]"), 2 packets
Source: 192.168.1.50
DNS: server.nigam.com
Destination: 192.168.1.255
DNS: [No reverse dns info available]
Overall scan start: Tue May 3 18:40:20 2016
Total email alerts: 37
Complete UDP range: [32412-32414]
Syslog hostname: nook
Global stats:
chain: interface: protocol: packets:
INPUT br1 udp 6
OUTPUT br1 udp 12
从路由器:
=-=-=-=-=-=-=-=-=-=-=-= Tue May 3 18:40:49 2016 =-=-=-=-=-=-=-=-=-=-=-=
Danger level: [2] (out of 5)
Scanned UDP ports: [42608-58785: 6 packets, Nmap: -sU]
iptables chain: INPUT (prefix "[UFW AUDIT]"), 6 packets
Source: 192.168.1.1
DNS: NigamNet
Destination: 192.168.1.69
DNS: nook.nigam.com
Overall scan start: Tue May 3 18:35:58 2016
Total email alerts: 39
Complete UDP range: [32911-60857]
Syslog hostname: nook
Global stats:
chain: interface: protocol: packets:
INPUT br1 udp 119
从本地主机:
=-=-=-=-=-=-=-=-=-=-=-= Tue May 3 18:40:47 2016 =-=-=-=-=-=-=-=-=-=-=-=
Danger level: [1] (out of 5) Multi-Protocol
Scanned UDP ports: [33335: 2 packets, Nmap: -sU]
iptables chain: INPUT (prefix "[UFW AUDIT]"), 1 packets
iptables chain: OUTPUT (prefix "[UFW AUDIT]"), 1 packets
Source: 127.0.0.1
DNS: localhost
Destination: 127.0.0.1
DNS: localhost
Overall scan start: Tue May 3 18:40:20 2016
Total email alerts: 5
Complete TCP range: [6789]
Complete UDP range: [33335]
Syslog hostname: nook
Global stats:
chain: interface: protocol: packets:
OUTPUT lo tcp 3
OUTPUT lo udp 3
INPUT lo tcp 3
INPUT lo udp 3
来自我的 Roku:
=-=-=-=-=-=-=-=-=-=-=-= Tue May 3 07:03:33 2016 =-=-=-=-=-=-=-=-=-=-=-=
Danger level: [3] (out of 5)
Scanned UDP ports: [41598: 1 packets, Nmap: -sU]
iptables chain: INPUT (prefix "[UFW BLOCK]"), 1 packets
Source: 192.168.1.108
DNS: NP-4124DU054440.nigam.com
Destination: 192.168.1.69
DNS: nook.nigam.com
Overall scan start: Tue May 3 00:12:39 2016
Total email alerts: 191
Complete UDP range: [39474-41598]
Syslog hostname: nook
Global stats:
chain: interface: protocol: packets:
INPUT br1 udp 195
答案1
如果您想减少这种噪音,您必须调整您的防火墙。
对于您来说,一种可能的方法可能是向您的防火墙添加一条规则,允许来自您的本地网络的 UDP 端口上的所有传入连接。