I have three routers in house. One is provided by ISP, Telus. It is 2 in 1, including modem and router. The second router is Buffalo WZR-HP-G300NH. It is placed beside Telus device. There two are connected with lan cable. Both are in the living room ground floor. The third router is located at basement. It is Buffalo WZR0HP-G300NH2. It is connected to the second router with wireless connection as client bridged.
I drew a reference layout.
Now, let me describe the network problem. It bothered me for two months.
I have a PC, Windows 7, in the basement, connect the router 3 with wire connection.
Normally I have no problem to working on this PC. Web browsing, online gaming, streaming video.
Until last month, I tried to install a Centos server. The server can not do update, can not wget remote files.
In the server terminal window, I can ping domain and get the IP address of Google.com, but I can not traceroute path to Google.com. It said network is unreachable, something like that.
When I tracert my host from Windows, the error looks like below: