tailieunhanh - Linux erver hacks 2003 phần 6

Trừ khi bạn đang sử dụng một bản phân phối Linux như Red Hat, cung cấp một công cụ đồ họa cho cấu hình xác thực hệ thống (system-config-auth, được hiển thị trong hình 1-1), bạn sẽ cần phải tự sửa đổi các tập tin cấu hình PAM cho các dịch vụ sẽ xác thực bằng cách sử dụng bộ điều khiển miền Windows của bạn. | 52 Using vtun over ssh to Circumvent NAT 1 ms ms ms 2 ms ms ms 3 ms ms ms 4 ms ms ms 5 ms ms ms 6 ms ms ms 7 ms ms ms 8 ms ms ms 9 ms ms 118. 8 ms 10 ms ms ms 11 ms ms ms 12 ms ms ms 13 ms ms ms In order to discourage connections to vtund on port 5000 of the server add a netfilter rule to drop connections from the outside world root@server iptables -A INPUT -t filter -i etho -p tcp --dport 5000 -j DROP This will allow local connections to get through since they use loopback and therefore require an ssh tunnel to server before accepting a connection. As you can see this can be an extremely handy tool to have around. In addition to giving live IP addresses to machines behind a NAT you can effectively connect any two networks together if you can obtain a single ssh connection between them originating from either direction . If your head is swimming from the configuration previously or if you re terminally lazy and don t want to figure out what to change when setting up your own client s take a look at the Automatic generator in Automatic Generator 53 . Notes The session name home in the above example must match on the client AND the server sides or you ll get an ambiguous server disconnected message. The same goes for the password field in the on both sides. It must be present AND match on both sides or the connection won t work. If you re having trouble connecting make sure you re using the same kernel version on both sides and that the server is up and .