Vì vậy, bạn sẽ làm gì tại tường lửa để cho phép các gói dữ liệu L2TP/IPSec để vượt qua? Bạn chỉ cần xác định các quy tắc tường lửa mà bạn sử dụng cho Giao thông vận tải giao thức TCP ID 47 Nguồn IP Bất kỳ cảng nào Nguồn Bất kỳ IP | 248 Part IV Deploying Solutions Using Firewall Products Put your SOCKS on SOCKS short for Sockets is a proxy server currently in version 5 that can process all types of network requests. After the client forwards network requests a SOCKS server performs an Application layer inspection and then fulfills the network request. The type of processing that occurs at the SOCKS server depends on the version you are using. SOCKS specifications are defined in several RFCs requests for comments and several versions of SOCKS servers are available. Even Microsoft Security and Acceleration ISA Server which we cover in Chapter 16 supports this protocol. Most of these SOCKS servers are commercial products but you can use a version that s available for non-commercial purposes free of charge. You can find out more about SOCKS where to get it how to implement it and how to wash dirty SOCKS at . Among other items this site contains a list of frequently asked questions FAQs that is a good starting point for learning more about SOCKS. Squid anyone A more specialized type of proxy server for the Linux platform is the free bit of software known affectionately as Squid. Squid is a caching server which means that it can accelerate Internet access by keeping local copies of frequently accessed Web pages and other Web objects such as graphics. Most Web browsers allow you to configure a Squid-based caching server as a proxy server. Squid servers generally only support Web requests which include HTTP and FTP requests that are issued by a proxy-aware client such as a Web browser. However Squid servers can t handle other network requests such as connections to mail servers. Several versions of Squid servers are available some of which are free and some of which are commercial software. You can find out more about Squid and how to implement it at . As was the case with the SOCKS Web site the best starting point to learn more is the FAQ section. Chapter 15 .
