openvpn获取可分配IP
2020-01-16查看合法的客户端地址分配范围，按照VLSM(可变长子网掩码)的规则，一共有64组，128个可用的地址。除去Server所使用的地址，一共有127个.
1、OpenVPN对客户端仅支持255.255.255.252这样的子网掩码。在windows客户端下，可以敲
cd D:\Program files\OpenVPN\bin
openvpn.exe --show-valid-subnets
2、On Windows, point-to-point IP support (i.e. --dev tun)
is emulated by the TAP-Windows driver. The major limitation
imposed by this approach is that the --ifconfig local and
remote endpoints must be part of the same 255.255.255.252
subnet. The following list shows examples of endpoint
pairs which satisfy this requirement. Only the final
component of the IP address pairs is at issue.
As an example, the following option would be correct:
--ifconfig 10.7.0.5 10.7.0.6 (on host A)
--ifconfig 10.7.0.6 10.7.0.5 (on host B)
because [5,6] is part of the below list.
[ 1, 2] [ 5, 6] [ 9, 10] [ 13, 14] [ 17, 18]
[ 21, 22] [ 25, 26] [ 29, 30] [ 33, 34] [ 37, 38]
[ 41, 42] [ 45, 46] [ 49, 50] [ 53, 54] [ 57, 58]
[ 61, 62] [ 65, 66] [ 69, 70] [ 73, 74] [ 77, 78]
[ 81, 82] [ 85, 86] [ 89, 90] [ 93, 94] [ 97, 98]
[101,102] [105,106] [109,110] [113,114] [117,118]
[121,122] [125,126] [129,130] [133,134] [137,138]
[141,142] [145,146] [149,150] [153,154] [157,158]
[161,162] [165,166] [169,170] [173,174] [177,178]
[181,182] [185,186] [189,190] [193,194] [197,198]
[201,202] [205,206] [209,210] [213,214] [217,218]
[221,222] [225,226] [229,230] [233,234] [237,238]
[241,242] [245,246] [249,250] [253,254]
3、server.conf增加
client-config-dir ccd
4、/etc/openvpn/ccd/user增加
ifconfig-push 10.11.12.9 10.11.12.10