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"The site you have attempted to access was unreachable" error going to in China, or slow performance accessing the same site.


Article ID: 257069


Updated On:


Cloud Secure Web Gateway - Cloud SWG


Users accessing Cloud SWG resources in China using WSS Agents.

Users connecting to Shanghai can access and subdomains without any issues, but if the same user connects to the Beijing data center, then users may see Communication errors as shown below, or the pages can become very slow to load/render.

Bypassing domain from Cloud SWG works around the issue.



WSS Agent

Cloud SWG China data centers


Local DNS servers, accessed by the Cloud SWG Proxy, were resolving hosts to Hong Kong IP addresses, where drops were more visible due to the fact that traffic going through China firewalls.


Addressed DNS issues within the Beijing data center environment, so that resolved to local in country IP addresses.

No DNS changes needed on the customer side.

Additional Information

HAR file appear to show the performance issues were queuing and connectivity related.

PCAPs confirmed this where we could see large numbers of retransmitted requests, with long delays. Te destination IP addresses resolved to Hong Kong servers.