nxtrace.org子域名：
ipv4.can-4837.endpoint.nxtrace.org
ipv4.pek-9808.endpoint.nxtrace.org
ipv4.pek-4134.endpoint.nxtrace.org
ipv4.pek-4837.endpoint.nxtrace.org
ipv4.pek-4538.endpoint.nxtrace.org
ipv4.sha-9929.endpoint.nxtrace.org
ipv4.can-9808.endpoint.nxtrace.org
ipv4.sha-9808.endpoint.nxtrace.org
ipv4.sha-4837.endpoint.nxtrace.org
ipv4.sha-4134.endpoint.nxtrace.org