{"id":158,"date":"2014-08-13T14:37:24","date_gmt":"2014-08-13T06:37:24","guid":{"rendered":"http:\/\/www.codeeel.com\/?p=158"},"modified":"2014-08-13T14:37:24","modified_gmt":"2014-08-13T06:37:24","slug":"centos-linux%e9%98%b2%e7%81%ab%e5%a2%99%e9%85%8d%e7%bd%ae","status":"publish","type":"post","link":"https:\/\/www.codeeel.com\/?p=158","title":{"rendered":"CentOS Linux\u9632\u706b\u5899\u914d\u7f6e"},"content":{"rendered":"

\u6267\u884c\u201dsetup\u201d\u547d\u4ee4\u542f\u52a8\u6587\u5b57\u6a21\u5f0f\u914d\u7f6e\u5b9e\u7528\u7a0b\u5e8f,\u5728\u201d\u9009\u62e9\u4e00\u79cd\u5de5\u5177\u201d\u4e2d\u9009\u62e9\u201d\u9632\u706b\u5899\u914d\u7f6e\u201d,\u7136\u540e\u9009\u62e9\u201d\u8fd0\u884c\u5de5\u5177\u201d\u6309\u94ae,\u51fa\u73b0\u9632\u706b\u5899\u914d\u7f6e\u754c\u9762,\u5c06\u201d\u5b89\u5168\u7ea7\u522b\u201d\u8bbe\u4e3a\u201d\u7981\u7528\u201d,\u7136\u540e\u9009\u62e9\u201d\u786e\u5b9a\u201d\u5373\u53ef.<\/p>\n

\u6216\u8005\u7528\u547d\u4ee4:
\n#\/sbin\/iptables -I INPUT -p tcp \u2013dport 80 -j ACCEPT
\n#\/sbin\/iptables -I INPUT -p tcp \u2013dport 22 -j ACCEPT
\n#\/etc\/rc.d\/init.d\/iptables save<\/p>\n

\u8fd9\u6837\u91cd\u542f\u8ba1\u7b97\u673a\u540e,\u9632\u706b\u5899\u9ed8\u8ba4\u5df2\u7ecf\u5f00\u653e\u4e8680\u548c22\u7aef\u53e3<\/p>\n

\u8fd9\u91cc\u5e94\u8be5\u4e5f\u53ef\u4ee5\u4e0d\u91cd\u542f\u8ba1\u7b97\u673a\uff1a
\n#\/etc\/init.d\/iptables restart<\/p>\n

\u9632\u706b\u5899\u7684\u5173\u95ed\uff0c\u5173\u95ed\u5176\u670d\u52a1\u5373\u53ef\uff1a<\/p>\n

\u67e5\u770b\u9632\u706b\u5899\u4fe1\u606f\uff1a
\n#\/etc\/init.d\/iptables status<\/p>\n

\u5173\u95ed\u9632\u706b\u5899\u670d\u52a1\uff1a
\n#\/etc\/init.d\/iptables stop<\/p>\n

\u6c38\u4e45\u5173\u95ed\uff1f\u4e0d\u77e5\u9053\u600e\u4e48\u4e2a\u6c38\u4e45\u6cd5\uff1a
\n#chkconfig \u2013level 35 iptables off<\/p>\n

1\uff09 \u4e34\u65f6\u751f\u6548\uff0c\u91cd\u542f\u540e\u590d\u539f
\n\u5f00\u542f\uff1a service iptables start
\n\u5173\u95ed\uff1a service iptables stop<\/p>\n

2\uff09 \u6c38\u4e45\u6027\u751f\u6548\uff0c\u91cd\u542f\u540e\u4e0d\u4f1a\u590d\u539f
\n\u5f00\u542f\uff1a chkconfig iptables on
\n\u5173\u95ed\uff1a chkconfig iptables off<\/p>\n

\u770b\u4e86\u597d\u51e0\u4e2a\u9875\u9762\u5185\u5bb9\u90fd\u6709\u9519\uff0c\u4e0b\u9762\u662f\u6b63\u786e\u65b9\u6cd5\uff1a
\n#\/sbin\/iptables -I INPUT -p tcp –dport 80 -j ACCEPT
\n#\/sbin\/iptables -I INPUT -p tcp –dport 22 -j ACCEPT<\/p>\n

\u7136\u540e\u4fdd\u5b58\uff1a
\n#\/etc\/rc.d\/init.d\/iptables save<\/p>\n

\u518d\u67e5\u770b\u662f\u5426\u5df2\u7ecf\u6709\u4e86\uff1a<\/p>\n

[root@vcentos ~]# \/etc\/init.d\/iptables status<\/div>\n
Table: filter<\/div>\n
Chain INPUT (policy ACCEPT)<\/div>\n
num target prot opt source destination<\/div>\n
1\u00a0ACCEPT udp — 0.0.0.0\/0 0.0.0.0\/0 udp dpt:80<\/strong><\/div>\n
2 ACCEPT tcp — 0.0.0.0\/0 0.0.0.0\/0 tcp dpt:80<\/div>\n
3 RH-Firewall-1-INPUT all — 0.0.0.0\/0 0.0.0.0\/0<\/div>\n
<\/div>\n
Chain FORWARD (policy ACCEPT)<\/div>\n
num target prot opt source destination<\/div>\n
1 RH-Firewall-1-INPUT all — 0.0.0.0\/0 0.0.0.0\/0<\/div>\n<\/div>\n

\u670d\u52a1\u5668\u906d\u53d7\u5230\u5927\u91cf\u7684\u5927\u91cfSYN_RECV\uff0c80\u7aef\u53f7\u5360\u6b7b\uff0c\u7f51\u7ad9\u6253\u4e0d\u5f00<\/p>\n

\u6ca1\u6709\u786c\u9632<\/p>\n

\u6709\u4ec0\u4e48\u529e\u6cd5\u53ef\u4ee5\u89e3\u51b3\u5417<\/p>\n

1
\nsysctl -w net.ipv4.tcp_syncookies=1 #\u542f\u7528\u4f7f\u7528syncookies
\nsysctl -w net.ipv4.tcp_synack_retries=1 #\u964d\u4f4esyn\u91cd\u8bd5\u6b21\u6570
\nsysctl -w net.ipv4.tcp_syn_retries=1 #\u964d\u4f4esyn\u91cd\u8bd5\u6b21\u6570
\nsysctl -w net.ipv4.tcp_max_syn_backlog=6000 #\u6700\u5927\u534a\u8fde\u63a5\u6570
\nsysctl -w net.ipv4.conf.all.send_redirects=0
\nsysctl -w net.ipv4.conf.all.accept_redirects=0 #\u4e0d\u63a5\u53d7\u91cd\u5b9a\u5411\u7684icmp\u6578\u64da\u5305
\nsysctl -w net.ipv4.tcp_fin_timeout=30
\nsysctl -w net.ipv4.tcp_keepalive_time=60
\nsysctl -w net.ipv4.tcp_window_scaling=1
\nsysctl -w net.ipv4.icmp_echo_ignore_all=1 #\u7981\u6b62ICMP
\nsysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1 #ICMP\u7981\u6b62\u5e7f\u64ad<\/p>\n

2.\u9650\u5236\u5355\u4f4d\u65f6\u95f4\u5185\u8fde\u63a5\u6570
\n\u5982
\niptables -N syn-flood
\niptables -A FORWARD -p tcp –syn -j syn-flood
\niptables -A INPUT -p tcp –syn -j syn-flood
\niptables -A syn-flood -p tcp –syn -m limit –limit 3\/s –limit-burst 1 -j ACCEP
\niptables -A syn-flood -j DROP
\niptables -A INPUT -i eth0 -p tcp ! –syn -m state –state NEW -j DROP
\niptables -A INPUT -p tcp –syn -m state –state NEW -j DROP<\/p>\n

3 \u5982\u679c\u8fd8\u662f\u4e0d\u884c\uff0c
\niptables -A INPUT -p tcp –dport 80 -m recent –name BAD_HTTP_ACCESS –update –seconds 60 –hitcount 30 -j REJECT
\niptables -A INPUT -p tcp –dport 80 -m recent –name BAD_HTTP_ACCESS –set -j ACCEP<\/p>\n

\u5982\u653b\u51fb\u8fc7\u6765\u7684\u6d41\u91cf\u5927\u4e8e\u4f60\u7684\u670d\u52a1\u5668\u7684\u6d41\u91cf\uff0c\u90a3\u5c31\u6ca1\u6709\u4ec0\u4e48\u529e\u6cd5\u4e86\uff0c\u5982\u679c\u6d41\u91cf\u4e0d\u5927\uff0c\u4ee5\u4e0a\u65b9\u6cd5\uff0c\u53ef\u4ee5\u6682\u65f6\u4fdd\u8bc1\u4f60\u768480\u53ef\u4ee5\u8bbf\u95ee<\/p><\/div>\n

<\/div>\n
\u5982\u679c\u4f60\u7684\u5185\u6838\u5df2\u7ecf\u652f\u6301iptables\u00a0\u00a0 connlimit\u53ef\u4ee5\u4f7f\u7528, iptables \u8bbe\u5b9a\u90e8\u4efd\uff0c\u4e5f\u53ef\u4ee5\u4f7f\u7528<\/p>\n

iptables -I FORWARD -p tcp –syn -m connlimit –connlimit-above 5 -j DROP
\n\u6216
\niptables -A INPUT -p tcp –syn –dport 80 -m connlimit –connlimit-above 5 -j REJECT<\/p><\/div>\n

<\/div>\n
\u5bf9\u4ed8SYN FLOOD\u7684\u8bdd\uff0c\u771f\u6b63\u8d77\u4f5c\u7528\u7684\u662f\uff1a
\nsysctl -w net.ipv4.tcp_syncookies=1 \u00a0\u00a0 \u00a0\u00a0\u00a0 #\u542f\u7528\u4f7f\u7528syncookies
\nsysctl -w net.ipv4.tcp_synack_retries=1 \u00a0\u00a0 \u00a0\u00a0\u00a0 #\u964d\u4f4esyn\u91cd\u8bd5\u6b21\u6570
\n\u5176\u4ed6IPTABLES\u7684\u9650\u5236\u901f\u5ea6\u529f\u80fd\u4e0d\u80fd\u7528\u6765\u5bf9\u4ed8SYN FLOOD\u7684\uff08\u4e0d\u80fd\u963b\u6b62\u62d2\u7edd\u670d\u52a1\uff0c\u4f46\u662f\u786e\u5b9e\u53ef\u4ee5\u9632\u6b62\u670d\u52a1\u5668CRASH\uff09\u3002<\/div>\n","protected":false},"excerpt":{"rendered":"

\u6267\u884c\u201dsetup\u201d\u547d\u4ee4\u542f\u52a8\u6587\u5b57\u6a21\u5f0f\u914d\u7f6e\u5b9e\u7528\u7a0b\u5e8f,\u5728\u201d\u9009\u62e9\u4e00\u79cd\u5de5\u5177\u201d\u4e2d\u9009\u62e9\u201d\u9632\u706b\u5899\u914d\u7f6e\u201d,\u7136\u540e\u9009\u62e9\u201d\u8fd0\u884c\u5de5\u5177\u201d\u6309\u94ae,\u51fa\u73b0\u9632\u706b\u5899\u914d\u7f6e\u754c\u9762,\u5c06\u201d\u5b89\u5168\u7ea7\u522b\u201d\u8bbe\u4e3a\u201d\u7981\u7528\u201d,\u7136\u540e\u9009\u62e9\u201d\u786e\u5b9a\u201d\u5373\u53ef. \u6216\u8005\u7528\u547d\u4ee4: #\/sbin\/iptables -I INPUT -p tcp \u2013dport 80 -j ACCEPT #\/sbin\/i<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[11],"tags":[74,92,93],"_links":{"self":[{"href":"https:\/\/www.codeeel.com\/index.php?rest_route=\/wp\/v2\/posts\/158"}],"collection":[{"href":"https:\/\/www.codeeel.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.codeeel.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.codeeel.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.codeeel.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=158"}],"version-history":[{"count":1,"href":"https:\/\/www.codeeel.com\/index.php?rest_route=\/wp\/v2\/posts\/158\/revisions"}],"predecessor-version":[{"id":159,"href":"https:\/\/www.codeeel.com\/index.php?rest_route=\/wp\/v2\/posts\/158\/revisions\/159"}],"wp:attachment":[{"href":"https:\/\/www.codeeel.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=158"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.codeeel.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=158"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.codeeel.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=158"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}