"connection hijacked/frozen"

I have had the following problem twice this week.

1. My internet connection could be made only to a specific site(wenxuecity.com and its subsites),
and all other connections were denied with a message "Server not found".

2. Not even the Window Defender's virus definition could be up-dated then.

3. All devices, three PCs and one smartphone, were having the same trouble at the same time.

4. It lasted 3-5 hours and then disappeared. The same problem reappeared in a few days.

I have been using a 15-year old Motorola cable modem and a low-end TP-Link router. They seem to 
work just fine before.

What caused the problem? What might be a quick solution? I tried the power-recycle of the 
modem/router, but it doesn't work. Haven't tried to re-set the router yet.

Pls help. Thanks.

所有跟帖： 

• did u call ur ISP? if not, better call when it happens again -奉旨灌水- ♀ (0 bytes) () 03/26/2015 postreply 19:04:26

• Will do. Thx! -career- ♂ (0 bytes) () 03/26/2015 postreply 19:10:37

• 先換個security好點的router/firewall，用不了幾十塊錢還能提高網速的。 -味苦- ♂ (0 bytes) () 03/27/2015 postreply 15:17:23

• 現在還不用DOCSIS3.0 modem，損失肯定是你自己 -味苦- ♂ (0 bytes) () 03/27/2015 postreply 15:22:26

• My internet plan is only 15/1 mps...why would a 3.0 modem help? -career- ♂ (105 bytes) () 03/27/2015 postreply 21:27:37

• cable是share band(同一巷子或同1block裏)。3.0前modem隻1個通道,高峰會被被擠掉/或延遲很久 -味苦- ♂ (142 bytes) () 03/28/2015 postreply 08:13:02

• Thx! -career- ♂ (0 bytes) () 03/28/2015 postreply 11:18:49

• Any maker/model recommendation? Thx! -career- ♂ (0 bytes) () 03/27/2015 postreply 22:16:34