Deploying Actual Cn2 In The United States And Hong Kong To Provide Better Site Access Protection For Overseas Users

1.

overall deployment ideas and preparations

preparation list: purchase a domain name, at least two overseas computer rooms (the united states, hong kong), it is recommended to use a chinese export line that supports cn2/gia or a cooperative cdn; prepare ssh keys, ssl certificates (let's encrypt), and monitoring accounts.
risk assessment: bandwidth, ddos risk, compliance and filing (note if mainland users are involved).

2.

select service provider and line type

key points: the hong kong node is suitable for users in asia/hong kong, macao and taiwan, and the us node covers the americas, europe and the united states. priority is given to suppliers that support cn2 (such as alibaba international cn2, china unicom cn2) or mainland china direct cdn nodes.
examples: alibaba cloud hong kong, tencent cloud hong kong, digitalocean (us), vultr (us) cooperate with domestic cn2 acceleration services.

3.

purchase and network configuration (example operation)

configuration after purchase: bind the public ip in the control panel and open the firewall port (http 80, https 443, ssh 22).
command example (linux): ufw allow 22/tcp; ufw allow 80/tcp; ufw allow 443/tcp; ufw enable.

4.

server basic environment construction

install nginx, certbot, and monitoring tools: apt update && apt install -y nginx certbot nginx-extras htop mtr iperf3.
create a user, upload website code to /var/www/example, and set permissions: chown -r www-data:www-data /var/www/example.

5.

enable https (let's encrypt)

get the certificate (example): certbot certonly --nginx -d example.com -d www.example.com.
nginx configuration key items: ssl_protocols tlsv1.2 tlsv1.3; ssl_prefer_server_ciphers on; use medium or higher security suite.

6.

nginx performance and proxy configuration

key configuration snippets: worker_processes auto; worker_connections 10240; sendfile on; tcp_nopush on; tcp_nodelay on.
proxy cache example: proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=mycache:10m max_size=1g inactive=60m;

7.

network layer tuning (linux kernel parameters)

modify /etc/sysctl.conf: net.core.default_qdisc = fq net.ipv4.tcp_congestion_control = bbr net.ipv4.tcp_tw_reuse = 1 net.core.somaxconn = 1024.
effective: sysctl -p; enable bbr: modprobe tcp_bbr; echo "tcp_bbr" > /etc/modules-load.d/bbr.conf.

8.

mtu and sharding optimization

check the path mtu: tracepath example.com; if fragmentation problems occur, adjust the network card mtu (example): ip link set dev eth0 mtu 1400.
at the cdn/load balancer front-end, it is often necessary to reduce the mtu to be compatible with cross-border links.

9.

multi-point deployment and traffic scheduling

solution: dns round robin, geodns or anycast + global cdn.
implementation: use cloudflare/dnsmadeeasy for geographical analysis. overseas users are prioritized for resolution to hong kong or us nodes, and domestic users are accelerated to the edge through cn2.

10.

bgp/multi-line computer room and back-to-origin strategy

if you use your own computer room or vps to support bgp, it is recommended to access multiple lines and enable bgp multi-homing; if you use a commercial cdn, configure the closest node to be preferred for return to origin and enable return to origin retry.
test bgp routing: traceroute -n to the target, use mtr to observe path jitter.

11.

protection and high availability

ddos protection: enable basic protection from cloud vendors or purchase advanced cleaning.
high availability: deploy the same site in two places and use health check + load balancing (for example: use dns health check to switch active and backup).

12.

caching and static resource distribution

put static resources (images, js, css) into cdn or s3/object storage and enable the long cache policy (cache-control: max-age=31536000).
set up reasonable caching for dynamic interfaces (short-term or per user), and enable gzip and brotli in nginx (if supported).

13.

monitoring and alarm configuration

key monitoring items: latency (rtt), packet loss rate, page load time, http 5xx rate, bandwidth usage.
tools: prometheus + grafana, datadog or cloud vendor’s own monitoring; configure smtp/slack alarms.

14.

test and acceptance command list

network test: ping -c 10 ;mtr -rw <domain name>; traceroute -n <domain name>; iperf3 -c .
page test: curl -i https://example.com; curl -ss --resolve example.com:443:ip https://example.com/ | head.

15.

continuous optimization methods

periodic checks: check mtr reports, logs, error rates every week, and adjust cache and backend connection numbers.
ab tests different nodes and caching strategies, and records ttfb and overall loading time in each region.

16.

frequently asked questions and troubleshooting tips

if the user reports slowness: first use mtr to confirm the packet loss point; if the last hop is slow, check the firewall speed limit or server cpu/io.
if the https handshake is slow, check the certificate chain, ocsp, tls version and sni configuration.

17.

q: why should we deploy and combine cn2 in hong kong and the united states at the same time?

answer: hong kong covers asia/hong kong, macao and taiwan with low latency, and the united states covers the americas and europe. using cn2 (or cn2 gia) can improve the stability and delay of the return trip from mainland china to overseas. the combination of the three can provide optimal paths and better disaster recovery for users in different regions.

18.

q: how can i quickly verify the access effectiveness of my site in different regions?

answer: use mtr/traceroute to test from the target region (you can use foreign vps or online tools such as keycdn tools, gcp cloud shell, webpagetest) to compare rtt, packet loss and ttfb; you can also use curl --resolve to specify resolution to a specific node for back-to-source testing.

19.

q: what are the most easily overlooked points in deployment that affect the experience?

a: commonly overlooked items include mtu leading to fragmentation, bbr not being enabled, improper ssl configuration (resulting in a slow handshake), inaccurate dns geo-resolution, and static resources not being placed on the cdn. checking each item one by one and verifying it with commands can significantly improve the experience.