I have exactly the same issue. I can't access Baidu, China Construction Bank, and other websites hosted in China about one week ago. Now Baidu works but not China Contruction Bank and else. I contacted Customer Security Assurance and they ask me to contact the bank instead.
Camcast needs to be transparent if they have some trigger in place to block our access to any website. We should be alerted on the block and also we should be able to dispute why we need access to the website.
Perhaps traces to the sites may help reveal some clues ?
Could you please provide a traceroute? We recently had more inquiries regarding the websites from China but they were blocked by China side.
Here are traceroute results from same laptop with both Verizon and Xfinity connection. The website ccb.com is not reachable on Xfinity, but it works on Verizon:
@papapan wrote: ... ccb.com is not reachable on Xfinity, but it works on Verizon ...
I can reach ccb.com using my Comcast connection. When one customer cannot reach a site but others can, it usually means the site is blocking that customer's public Comcast IP. You can look up your IP at https://www.google.com/search?q=IP. You'll probably need to ask the site's admins for help with this.
Switching to another carrier's network presents a different IP address to the site. The fact that you can reach the sites with when your IP changes increases the probability that it's not Comcast that's blocking you, it's the site. Your trace shows this as well:
12 62 ms 65 ms 64 ms as4837-pe01.11greatoaks.ca.ibone.comcast.net [220.127.116.11]
13 229 ms 229 ms * 18.104.22.168
Hop #12 is the last Comcast hop. Hop #13 is an IP that assigned to China's "CNCGROUP". Your situation is similar to the one described in https://forums.xfinity.com/t5/Your-Home-Network/Cannot-visit-certain-oversea-websites/m-p/3235627.
My trace to ccb.com looks like this:
C>tracert -4 ccb.com
Tracing route to ccb.com [22.214.171.124] over a maximum of 30 hops:
1 34 ms 10 ms 10 ms router1 [192.168.1.1]
2 28 ms 26 ms 19 ms 126.96.36.199
3 18 ms 19 ms 17 ms te-0-6-0-0-sur02.york.pa.pitt.comcast.net [188.8.131.52]
4 40 ms 17 ms 18 ms 184.108.40.206
5 19 ms 24 ms * 220.127.116.11
6 49 ms 36 ms 28 ms be-34-ar01.mckeesport.pa.pitt.comcast.net [18.104.22.168]
7 38 ms 28 ms 35 ms 22.214.171.124
8 * * * Request timed out.
9 93 ms 101 ms 92 ms CHINA-TELEC.ear2.LosAngeles1.Level3.net [126.96.36.199]
10 * * * Request timed out.
11 * * * Request timed out.
12 * * * Request timed out.
13 * * * Request timed out.
14 * * * Request timed out.
15 * * * Request timed out.
16 * * * Request timed out.
17 265 ms * 252 ms 188.8.131.52.static.bjtelecom.net [184.108.40.206]
18 280 ms * 279 ms 220.127.116.11.broad.bj.bj.dynamic.163data.com.cn [18.104.22.168]
19 266 ms * 272 ms 22.214.171.124
20 270 ms * 269 ms 126.96.36.199
21 417 ms * 300 ms 188.8.131.52
22 * * * Request timed out.
23 284 ms * 285 ms 184.108.40.206
@papapan - Thank you! I was also able to reach ccb.com website. As BruceW mentioned, you may need to reach out to the CCB customer support and ask them to assist.
@BruceW - Thank you for your help