03-iptables-实验

03-iptables-实验

实验

A(172.16.11.206)
B(172.16.11.216)
C(172.16.11.207)

1 允许B访问A而C不行

# A
[root@husa ~]# iptables -L -n -v
Chain INPUT (policy ACCEPT 782 packets, 74731 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain OUTPUT (policy ACCEPT 72 packets, 12516 bytes)
 pkts bytes target     prot opt in     out     source               destination         
[root@husa ~]# iptables -t filter -A INPUT -s 172.16.11.216 -d 172.16.11.206 -j ACCEPT
[root@husa ~]# iptables -t filter -A INPUT -s 172.16.11.207 -d 172.16.11.206 -j DROP
[root@husa ~]# iptables -t filter -L -n -v   
Chain INPUT (policy ACCEPT 53 packets, 4997 bytes)
 pkts bytes target     prot opt in     out     source               destination         
    0     0 ACCEPT     all  --  *      *       172.16.11.216       172.16.11.206      
    0     0 DROP       all  --  *      *       172.16.11.207       172.16.11.206      

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination         

Chain OUTPUT (policy ACCEPT 29 packets, 4152 bytes)
 pkts bytes target     prot opt in     out     source               destination  


# B

[root@husa ~]# ssh [email protected]
The authenticity of host '172.16.11.206 (172.16.11.206)' can't be established.
ECDSA key fingerprint is d8:88:76:ef:30:e0:f5:f7:4b:a2:63:51:55:2e:74:28.
Are you sure you want to continue connecting (yes/no)? yes
Warning: Permanently added '172.16.11.206' (ECDSA) to the list of known hosts.
root@172.16.11.206's password: 
Last failed login: Sun Jan 24 19:16:54 CST 2016 from 172.16.16.1 on ssh:notty
There was 1 failed login attempt since the last successful login.
Last login: Sun Jan 24 19:16:39 2016 from 172.16.11.207

[root@husa ~]# ip addr
2: eno16777736:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:4d:a0:50 brd ff:ff:ff:ff:ff:ff
    inet 172.16.11.206/16 brd 172.16.255.255 scope global eno16777736
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe4d:a050/64 scope link 
       valid_lft forever preferred_lft forever

# C
[root@localhost ~]# ssh [email protected]
ssh: connect to host 172.16.11.206 port 22: Connection timed out
|               # 由于A直接将pact丢弃导致Cssh链接没有任何响应


[root@localhost ~]# ping 172.16.11.206     
PING 172.16.11.206 (172.16.11.206) 56(84) bytes of data.
                # ping也ping不通

# A动态查看匹配的规则

Every 1.0s: iptables -L -n -v --line-numbers                                                    Sun Jan 24 19:24:44 2016

Chain INPUT (policy ACCEPT 528 packets, 53690 bytes)
num   pkts bytes target     prot opt in     out     source               destination
1       43  5995 ACCEPT     all  --  *      *       172.16.11.216        172.16.11.206
2       74  6168 DROP       all  --  *      *       172.16.11.207        172.16.11.206

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
num   pkts bytes target     prot opt in     out     source               destination

Chain OUTPUT (policy ACCEPT 146 packets, 25966 bytes)
num   pkts bytes target     prot opt in     out     source               destination

2 限制C不能pingA但是可以sshA

# A
[root@husa ~]# iptables -F
[root@husa ~]# iptables -t filter -A INPUT -s 172.16.11.207 -d 172.16.11.206 -p icmp -j REJECT  
[root@husa ~]# iptables -L -n -v --line-numbers
Chain INPUT (policy ACCEPT 10 packets, 860 bytes)
num   pkts bytes target     prot opt in     out     source               destination         
1        0     0 REJECT     icmp --  *      *       172.16.11.207        172.16.11.206        reject-with icmp-port-unreachable

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
num   pkts bytes target     prot opt in     out     source               destination         

Chain OUTPUT (policy ACCEPT 5 packets, 872 bytes)
num   pkts bytes target     prot opt in     out     source               destination 

# C

[root@localhost ~]# ping 172.16.11.206
PING 172.16.11.206 (172.16.11.206) 56(84) bytes of data.
From 172.16.11.206 icmp_seq=1 Destination Port Unreachable
From 172.16.11.206 icmp_seq=2 Destination Port Unreachable
From 172.16.11.206 icmp_seq=3 Destination Port Unreachable
^C
--- 172.16.11.206 ping statistics ---
3 packets transmitted, 0 received, +3 errors, 100% packet loss, time 2491ms

[root@localhost ~]# ssh [email protected]
root@172.16.11.206's password: 
Last login: Sun Jan 24 19:22:25 2016 from 172.16.250.35
[root@husa ~]# ip addr show
1: lo:  mtu 65536 qdisc noqueue state UNKNOWN 
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eno16777736:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:4d:a0:50 brd ff:ff:ff:ff:ff:ff
    inet 172.16.11.206/16 brd 172.16.255.255 scope global eno16777736
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe4d:a050/64 scope link 
       valid_lft forever preferred_lft forever
3: eno33554984:  mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:0c:29:4d:a0:5a brd ff:ff:ff:ff:ff:ff
    inet 192.168.200.137/24 brd 192.168.200.255 scope global eno33554984
       valid_lft forever preferred_lft forever
    inet6 fe80::20c:29ff:fe4d:a05a/64 scope link 
       valid_lft forever preferred_lft forever

可以看到C不能pingA但是可以sshA

3 A有两张网卡，其中IP为172.16.11.206另一IP为192.16.200.137，限制C只能从192.16.200.137ping通

# A

[root@husa ~]# iptables -t filter -A INPUT -s 172.16.11.207 -p icmp -j REJECT

# C

[root@localhost ~]# ping 172.16.11.206
PING 172.16.11.206 (172.16.11.206) 56(84) bytes of data.
From 172.16.11.206 icmp_seq=1 Destination Port Unreachable
From 172.16.11.206 icmp_seq&#