Troubleshooting - Virtual Private Cloud - Alibaba Cloud Documentation Center

This topic describes how to use the troubleshooting feature of Virtual Private Cloud (VPC) to troubleshoot VPC connectivity issues, unexpected fees, and quota issues. The troubleshooting feature also provides solutions. Your services and instance configurations are not affected during the analysis process.

Procedure

Log on to the VPC console.
In the left-side navigation pane, click Troubleshooting.
On the VPC tab, select an issue type and follow the instructions at the bottom of the page to obtain references, suggestions, or perform troubleshooting.
For more information about VPC issue types, troubleshooting methods, and references, see Issue types.

Issue types

Issue type	Possible cause/Suggestion
Network Connectivity	If you encounter network connectivity issues, you can troubleshoot based on the following information: ECS instances in a VPC cannot communicate with each other Inbound and outbound traffic of Elastic Compute Service (ECS) instances are controlled by security group rules and the network ACLs of the vSwitch where the ECS instances reside. For more information, see Create and manage network ACLs and Add security group rules. ECS instances in a VPC cannot access ECS instances in another VPC You can establish cross-VPC communication by using VPC peering connections or by using a Cloud Enterprise Network (CEN) instance and configuring routes. In addition, make sure that the security group rules and network ACL rules allow access from the ECS instances and vSwitches. For more information, see the following topics: Create and manage a VPC peering connection Use Enterprise Edition transit routers to connect VPCs across regions and accounts Create and manage a network ACL Add a security group rule The network latency is high when ECS instances in a VPC access other cloud services or ECS instances The network latency between instances in the same zone is low. If you are experiencing a high response time, check whether the source and destination instances are deployed in different zones. Unable to access the Internet Troubleshoot Internet access failures based on the following information: IPv4 scenarios: Check whether the ECS instance is assigned a public IP address or associated with an elastic IP address (EIP). Check whether an Internet NAT gateway is created in the VPC, whether SNAT entries are configured, and whether routes that point to the Internet NAT gateway exist. For more information, see Use the SNAT feature of an Internet NAT gateway to access the Internet. If an IPv4 gateway is enabled in the VPC, check whether a default route that points to the IPv4 gateway is configured. For more information, see Create and manage an IPv4 gateway. IPv6 scenarios: Check whether an IPv6 gateway is created in the VPC and whether a default route that points to the IPv6 gateway is configured. Check whether IPv6 Internet bandwidth is enabled for the ECS instance. For more information, see Allow an ECS instance in a VPC to communicate with external IPv6 clients over the Internet. Note You can also send connectivity probes to troubleshoot issues such as ECS instances in a VPC cannot communicate with each other and ECS instances in a VPC cannot access ECS instances in another VPC. Connectivity probes: You can use the reachability analyzer of Network Intelligence Service (NIS) to check the connectivity between a VPC and a network resource. For more information about the reachability analyzer, see Work with the reachability analyzer.
Connection between VPC and External Network	If you encounter connection issues between a VPC and an external network, you can troubleshoot based on the following information: Connect different VPCs You can enable private communication between VPCs by using CEN, VPN gateways, VPC peering connections, or PrivateLink. For more information about the preceding solutions, see Overview of VPC connections. Connect a VPC to the Internet You can enable ECS instances in a VPC to communicate with the Internet by assigning public IP addresses to the ECS instances, associating EIPs with the ECS instances, using a NAT gateway, or using Server Load Balancer (SLB). For more information, see Internet access overview. Connect a VPC to a data center You can connect a data center to a VPC through a VPN gateway, an Express Connect circuit, or Smart Access Gateway (SAG). For more information, see Connect a data center to a VPC.
Fee	If you encounter issues related to service activation and billing, you can troubleshoot based on the following information: Billing of flow logs You are charged log generation fees and service fees of Simple Log Service. Log generation fees are charged by VPC on a tiered pricing model. Service fees are charged by Simple Log Service. For more information, see Billing of flow logs. Billing of VPC peering connections You are not charged for intra-region VPC peering connections. You are charged data transfer fees for inter-region VPC peering connections. The billing is managed by Cloud Data Transfer (CDT). For more information, see What is CDT? Billing of traffic mirroring Total fee = Instance fee + Data transfer fee (currently not charged) For more information, see Billing.
Quota	If you encounter issues related to insufficient VPC quotas, you can troubleshoot based on the following information: Limits on VPC quotas For more information, see relevant documentation for VPC quotas. For more information, see Resource quotas. A resource quota is about to be exhausted You can log on to the Quota Center console or VPC console to request a quota increase. For more information, see Manage VPC quotas.