設定 VPN Client IP

1. 查看 vpn_myadapter 沒有指定 IP，無法連線 VPN server 端的 192.168.1.254。
   

   [root@dywftp vpnclient]# ifconfig vpn_myadapter
   vpn_myadapter Link encap:Ethernet  HWaddr 00:AC:E8:A9:C9:4D  
             inet6 addr: fe80::2ac:e8ff:fea9:c94d/64 Scope:Link
             UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
             RX packets:290 errors:0 dropped:0 overruns:0 frame:0
             TX packets:245 errors:0 dropped:0 overruns:0 carrier:0
             collisions:0 txqueuelen:500 
             RX bytes:20090 (19.6 KiB)  TX bytes:20254 (19.7 KiB)
   
   [root@dywftp vpnclient]# ping -c3 192.168.1.254
   PING 192.168.1.254 (192.168.1.254) 56(84) bytes of data.
   
   --- 192.168.1.254 ping statistics ---
   3 packets transmitted, 0 received, 100% packet loss, time 11999ms
   

2. 設定 vpn_myadapter IP 為 192.168.1.200/24，就可以連線 VPN server 端的 192.168.1.254。
   

   [root@dywftp vpnclient]# ifconfig vpn_myadapter 192.168.1.200/24
   [root@dywftp vpnclient]# ping -c3 192.168.1.254
   PING 192.168.1.254 (192.168.1.254) 56(84) bytes of data.
   64 bytes from 192.168.1.254: icmp_seq=1 ttl=64 time=1.80 ms
   64 bytes from 192.168.1.254: icmp_seq=2 ttl=64 time=0.643 ms
   64 bytes from 192.168.1.254: icmp_seq=3 ttl=64 time=0.603 ms
   
   --- 192.168.1.254 ping statistics ---
   3 packets transmitted, 3 received, 0% packet loss, time 2003ms
   rtt min/avg/max/mdev = 0.603/1.015/1.801/0.556 ms
   

3. 在 Linux 要由 VPN server 的 DHCP 自動取得 vpn_myadapter 的 IP，可以使用 dhclient 命令。
   

   [root@dywftp ~]# dhclient vpn_myadapter &
   [1] 22730
   [root@dywftp ~]# ifconfig vpn_myadapter
   vpn_myadapter Link encap:Ethernet  HWaddr 00:AC:E8:A9:C9:4D  
             inet addr:192.168.1.11  Bcast:192.168.1.255  Mask:255.255.255.0
             inet6 addr: fe80::2ac:e8ff:fea9:c94d/64 Scope:Link
             UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
             RX packets:6701 errors:0 dropped:0 overruns:0 frame:0
             TX packets:85 errors:0 dropped:0 overruns:0 carrier:0
             collisions:0 txqueuelen:500 
             RX bytes:416312 (406.5 KiB)  TX bytes:11980 (11.6 KiB)
   
   [1]+  Done                    dhclient vpn_myadapter
   

4. vpn_myadapter 釋出取得的 IP，可以使用 dhclient -r 命令。
   

   [root@dywftp ~]# dhclient -r vpn_myadapter
   [root@dywftp ~]# ifconfig vpn_myadapter
   vpn_myadapter Link encap:Ethernet  HWaddr 00:AC:E8:A9:C9:4D  
             BROADCAST MULTICAST  MTU:1500  Metric:1
             RX packets:6786 errors:0 dropped:0 overruns:0 frame:0
             TX packets:94 errors:0 dropped:0 overruns:0 carrier:0
             collisions:0 txqueuelen:500 
             RX bytes:421539 (411.6 KiB)  TX bytes:12838 (12.5 KiB)
   

5. 當 VPN Clinet 也是在 VLAN 且網段也是 192.168.1.0/24 時......