iptables的基本參數和簡單使用方法

時間 2019-11-06

原文原文鏈接

##規則鏈與策略:
###規則:app

ACCEPT：容許經過
LOG：記錄日誌
REJECT：拒絕經過，給出返回值
DROP：丟棄
###規則鏈:
PREROUTING：路由前處理
INPUT：處理入站數據
OUTPUT：處理出站數據
FORWARD：處理轉發數據
POSTROUTING：路由後處理
raw表：肯定是否對數據包狀態跟蹤
mangle表：設置標記
nat表：修改數據包源、目標IP或端口
filter表：過濾
###規則順序
規則表前後順序：raw表→mangle表→nat表→filter表
規則鏈前後順序：
入站：PREROUTING→INPUT
出站：OUTPUT→POSTROUTING
轉發：PREROUTING→FORWARD→POSTROUTING
###基本參數：
iptables [-t 表名] 選項 [鏈名] [條件] [控制類型]ssh

Usage: iptables -[ACD] chain rule-specification [options]
       iptables -I chain [rulenum] rule-specification [options]
       iptables -R chain rulenum rule-specification [options]
       iptables -D chain rulenum [options]
       iptables -[LS] [chain [rulenum]] [options]
       iptables -[FZ] [chain] [options]
       iptables -[NX] chain
       iptables -E old-chain-name new-chain-name
       iptables -P chain target [options]
       iptables -h (print this help information)

Commands:
Either long or short options are allowed.
  --append  -A chain            Append to chain
  --check   -C chain            Check for the existence of a rule
  --delete  -D chain            Delete matching rule from chain
  --delete  -D chain rulenum
                                Delete rule rulenum (1 = first) from chain
  --insert  -I chain [rulenum]
                                Insert in chain as rulenum (default 1=first)
  --replace -R chain rulenum
                                Replace rule rulenum (1 = first) in chain
  --list    -L [chain [rulenum]]
                                List the rules in a chain or all chains
  --list-rules -S [chain [rulenum]]
                                Print the rules in a chain or all chains
  --flush   -F [chain]          Delete all rules in  chain or all chains
  --zero    -Z [chain [rulenum]]
                                Zero counters in chain or all chains
  --new     -N chain            Create a new user-defined chain
  --delete-chain
            -X [chain]          Delete a user-defined chain
  --policy  -P chain target
                                Change policy on chain to target
  --rename-chain
            -E old-chain new-chain
                                Change chain name, (moving any references)
Options:
    --ipv4      -4              Nothing (line is ignored by ip6tables-restore)
    --ipv6      -6              Error (line is ignored by iptables-restore)
[!] --protocol  -p proto        protocol: by number or name, eg. `tcp'
[!] --source    -s address[/mask][...]
                                source specification
[!] --destination -d address[/mask][...]
                                destination specification
[!] --in-interface -i input name[+]
                                network interface name ([+] for wildcard)
 --jump -j target
                                target for rule (may load target extension)
  --goto      -g chain
                              jump to chain with no return
  --match       -m match
                                extended match (may load extension)
  --numeric     -n              numeric output of addresses and ports
[!] --out-interface -o output name[+]
                                network interface name ([+] for wildcard)
  --table       -t table        table to manipulate (default: `filter')
  --verbose     -v              verbose mode
  --wait        -w              wait for the xtables lock
  --line-numbers                print line numbers when listing
  --exact       -x              expand numbers (display exact values)
[!] --fragment  -f              match second or further fragments only
  --modprobe=<command>          try to insert modules using this command
  --set-counters PKTS BYTES     set the counter during insert/append
[!] --version   -V              print package version.

###基本使用方法：
####查看已有規則：
# iptables -L
####清空全部規則：
# iptables -F
####拒絕INPUT
# iptables -P INPUT DROP
####容許全部ping：
# iptables -I INPUT -p icmp -j ACCEPT
####在末尾加入容許未被其餘規則匹配的數據包：
# iptables -t filter -A INPUT -j -ACCEPT
####刪除INPUT第二條規則：
# iptables -D INPUT 2
####僅容許來自172.27.8.0/22的用戶鏈接ssh服務tcp

iptables -I INPUT -s 172.27.8.0/22 -p tcp --dport 22 -j ACCEPT

# iptables -A INPUT -p tcp  --dport 22 -j REJECT

####不容許任何用戶訪問本機3306端口ide

iptables -I INPUT -p tcp --dport 3306 -j REJECT

# iptables -I INPUT -p udp --dport 3306 -j REJECT

####拒絕其餘用戶經過網卡eth1訪問本機http服務
# iptables -I INPUT -i eth1 -p tcp --dport 80 -j REJECT
####禁止用戶訪問www.baidu.com
# iptables -I FORWARD -d www.baidu.com -j DROP
####禁止172.27.8.22的用戶上網
# iptables -I FORWARD -s 172.27.8.22 -j DROP
###流量均衡：
將訪問流量分流至內網三臺不一樣主機：this

iptables -A PREROUTING -i eth1 -p tcp --dport 80 -m state --state NEW -m nth --counter 0 --every 3 --packet 0 -j DNAT -to-destination 172.27.8.10
iptables -A PREROUTING -i eth1 -p tcp --dport 80 -m state --state NEW -m nth --counter 0 --every 3 --packet 0 -j DNAT -to-destination 172.27.8.20
iptables -A PREROUTING -i eth1 -p tcp --dport 80 -m state --state NEW -m nth --counter 0 --every 3 --packet 0 -j DNAT -to-destination 172.27.8.30

使用上述操做，規則僅當前有效，如需重啓依然有效，執行service iptables save 將規則寫入/etc/sysconfig/iptables中，
順便再貼一個iptables配置：rest

# Generated by iptables-save v1.4.7 on Thu Apr 16 01:33:03 2015
*filter
:INPUT DROP [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
#容許本機迴環地址
-A INPUT -i lo -p all -j ACCEPT
##容許這些IP全部操做
-A INPUT -s 110.122.120.54/32 -j ACCEPT 
-A INPUT -s 110.122.120.98/32 -j ACCEPT
##容許DNS解析
-A INPUT -p udp --sport 53 -j ACCEPT
#容許5672端口訪問
-A INPUT -s 10.10.2.160 -p tcp --sport 5672 -j ACCEPT
##禁止eth0上27017入站和出站
-A INPUT -i eth0  -p tcp --dport 27017 -j DROP
-A OUTPUT -o eth0 -p tcp --sport 27017 -j DROP
##容許zabbix的10050端口
-A INPUT -s 100.10.2.160 -p tcp --dport 10050 -j ACCEPT
##運許snmp的161端口
-A INPUT -s 100.10.2.160 -p tcp --dport 10050 -j ACCEPT
##容許程序主機訪問指定IP的4506端口
-A INPUT -s 172.27.1.75 -p tcp --dport 4506 -j ACCEPT
##容許下列端口訪問
-A INPUT -p tcp --dport 8080 -j ACCEPT
-A INPUT -p tcp --dport 8090 -j ACCEPT
-A INPUT -p tcp --dport 13000 -j ACCEPT
-A INPUT -p tcp --dport 9000 -j ACCEPT
-A INPUT -p tcp --dport 8888 -j ACCEPT
COMMIT