How To Deploy A Hybrid Cloud Environment In CN2 Singapore Data Center To Ensure Network Stability

1.

Preliminary Planning and Needs Assessment

Determine the hybrid cloud objectives (disaster recovery, elastic scaling, or primary/secondary data storage) and list the requirements for bandwidth, latency, compliance, and public network access.
Evaluate traffic direction: Whether to use dedicated services like CN2 GIA depends on whether there is more traffic going back and forth within China or going overseas.
List the key applications, ports, protocols, and SLA requirements, and create a priority list for subsequent design.

2.

Select hosting facility and line type

Confirm whether the server room supports China Telecom CN2 access, and ask if there is a distinction between CN2-GIA/GT and direct links to mainland China.
Choose Cross-connect or rent a public network exit as needed, giving priority to hosting with dual ISPs (China Telecom + other international ISPs) to achieve geographically redundant setup.
Request the BGP ASN, peer IP, bandwidth ports, and delivery schedule provided by the IDC.

3.

Comparison and Selection of Hybrid Cloud Connection Methods

List three common ways: IPsec VPN (quick deployment, low cost), dedicated line connectivity (AWS Direct Connect/Azure ExpressRoute/GCP Interconnect, stable and low latency), SD-WAN (intelligent traffic routing, supports multiple links).
If there are strict requirements for latency/packet loss on the mainland China link, prioritize CN2+ dedicated lines or cloud Direct Connect solutions with a CN2 exit.

4.

Network Topology and Redundancy Design

It is recommended to use two upstream connections (two ISPs or two separate international links) and enable BGP multi-pathing (ECMP) or primary/secondary strategies ； Deploy two border routers + two firewalls inside the server room.
Internal VLAN segmentation is used (management, production, database, backup), and MLAG/stack is enabled on the core switches to achieve redundancy at the switching layer.

5.

Key Points for Practical Use of BGP and Routing Policies

Configure BGP neighbors on the border router: Local ASN, peer ASN, neighbor IP, password (MD5). Example (Cisco style):
router bgp 65001
neighbor 203.0.113.1 remote-as 4812
neighbor 203.0.113.1 password YOURMD5
Apply local pref (local-pref), AS_PATH prepending or community is used for traffic engineering.

6.

Layer2/Layer3 Extensions and Data Plane Optimization

To extend Layer 2 to the cloud, use EVPN-VXLAN or the L2 Gateway provided by the cloud provider (be mindful of MTU and ARP timeouts).
Ensure end-to-end MTU consistency (1500 or 9000 is recommended), configure jumbo frames on Linux and switches, and verify PMTU. TCP tuning uses tcp_Timestamps, window size, and BBR congestion control to reduce latency.

7.

Security Policies and DDoS Protection

Firewall policies are deployed at both the server room boundary and in the cloud, using ACL allowlists to restrict access to management passwords.
Order DDoS mitigation services from data center providers or cloud vendors (priced based on peak volume and type), and configure black hole routing (hash-based or community-triggered) on the router as a contingency measure.

8.

Monitoring, Logging, and Alerting Configuration

Deploy network monitoring (Prometheus + node_Exporter + blackbox/iperf) and traffic collection (NetFlow/sFlow/IPFIX) are used for bandwidth and traffic analysis.
Configure active probing (daily/hourly) using iperf3 or ping-traceroute scripts, and write the results to a time-series database. Set packet loss/RTT threshold alerts with notifications via SMS/email/DingTalk.

9.

Steps for deployment verification and performance testing

Verify sequentially before going online: Link is UP/BGP neighbor established, routes are reachable, ACL and firewall rules are in place, MTU is consistent.
Execute performance testing: iperf3 -c <对端IP> -P4 -t60 Test bandwidth ； Use mtr or traceroute to check the number of hops and packet losses in the path ； Use the tcptraceroute or ss command to confirm the TCP handshake time.

10.

Fault Drill and Ops Manual

Writing a Runbook includes: Single-link failover, handling of BGP neighbor disconnections, dealing with packet loss caused by link congestion, DDoS incident response process.
Conduct regular drills (quarterly) and document the achievement of RTO/RPO targets as well as improvement measures. Keep the contact list updated and ensure remote control permissions are tested and working properly.

11.

Question: When connecting CN2 Singapore data centers to cloud providers, how can stability for access from mainland China be ensured?

12.

Answer: Give priority to using CN2 exits or CN2-GIA type dedicated lines for direct connection to China, in conjunction with cloud providers’ Direct Connect/ExpressRoute, while setting local-pref and AS values in the routing_PATH policy ； At the same time, retain the second non-CN2 link as a backup and enable BFD for accelerated detection and rapid BGP convergence.

13.

Question: If there is link jitter or high packet loss, what should be the troubleshooting order?

14.

Answer: Start by checking at the physical layer (fiber optic faults, SFP/port errors), then check the switch/router interface error statistics ； Use mtr/iperf for end-to-end testing to determine at which hop packet loss occurs ； Finally, analyze using NetFlow to determine whether it is abnormal traffic or DDoS, and take appropriate measures (throttling/blackhole/cleaning).

15.

Question: How to achieve intelligent application-level traffic scheduling in a hybrid cloud to improve stability?

16.

Answer: Deploy SD-WAN or application gateways with health checks (HTTP/TCP probes) to dynamically select paths based on latency/packet loss/bandwidth ； Use session stickiness for important sessions, or implement retry and idempotent designs at the application layer to ensure smooth business migration during link switching.