如果modem是Enthernet接口的话，是否可以再加一个Hub联2台电脑？如果modem是USB接口的话，又该怎么办？Singnet提供的ADSL modem好像只有USB接口的。

谢谢不吝赐教！

1) Modem with Ethernet connector. Can connect two computer using a hub with the modem? Yes and no.
No: You cannot simply connect the modem to two computers with a hub. That won't work.
Yes: You can still use this configuration, but install Sygate Home/Office Network for its proprietary single NIC-mode gateway. After this, both computers can access the Internet (the one with Sygate installed will be the server), but they will not be able to communicate with each other using SMB (i.e., better known as "Network Neighbourhood"), though normal TCP/IP communication is still okay.

2) Modem with USB connector. Not much choice but to connect it directly to one of the computers, and use it as the gateway. (In this case, almost all gateway software, including Sygate, can be used, as you have 2 network connections on the server--the modem, and the NIC.)

3) Modem with Ethernet connector. Get a router (quite cheap nowadays as compared to a few years back), which saves you from always turning one computer on as server.

4) ..... Explore it! There are still many more alternative ways to go...

2 PC share a WAN link via hub is OK.
Two PCs are virtually seen as one on the WAN.

１．竞争构架：最左侧的竞争构架，价格低廉，配置方便，但网络性能严重受到制约，电脑台数少时还可勉强使用。随着台数增多，网络速度将严重下降。２．代理构架：中间左边的代理构架，价格相对便宜（只需添置一张网卡），配置也相对容易，但对于代理服务器的机器需长期开机并保持稳定，并且不易扩展网络容量，受到很多限制。
３．路由构架：中间右边的路由构架，价格中等，配置稍微复杂，但网络可扩展性能好，网络性能也较好。基本上除少数应用程序不能正常使用外，没有什么限制。
４．交换构架：最右边的交换构架，价格非常昂贵，配置也很复杂，但优点是速度快，可扩展性能好。但由于价格过高，一般不见于家用。

注意：
１．有些调制解调器带有双接口（ＵＳＢ＋以太），实际是在其中集成了集线功能，不推荐使用。
２．市场上出售的宽带路由器，实际上是路由器集成了交换机（少数）或者集线器（大多数）。集成集线器的广域网速度会因局域网流量而受到影响（比如Ａ从Ｂ处拷贝电影会大大影响Ｂ访问因特网的速度；而集成交换机的则影响比较小。

You will be doomed with tons of problems if you do so. I'm not saying that that kind of connection is out, just that, it is simply a bad choice given the WAN connection he/she's using.

:^P