NAT FAQs

After creating a new NAT gateway and binding an EIP, why is it impossible to access the public network through the NAT gateway?

It is advisable to verify the route table. For intranet IPs to access the public network through NAT, a route targeting the NAT gateway must be set up.

Multiple Linux OS-based BCC instances accessing concurrently via NAT gateway experience occasional connect timeouts on the Linux server side?

Due to the implementation of the Linux OS kernel, enabling net.ipv4.tcp_tw_recycle on a server might cause the Linux kernel to drop TCP connection requests, leading to timeouts or failures. It is recommended to disable the net.ipv4.tcp_tw_recycle option on the server side or turn off the net.ipv4.tcp_timestamps option on the client side.

Can Baidu Cloud Compute bound to EIP still perform ingress/egress access via NAT gateway?

No. When a Baidu Cloud Compute instance binds to an EIP, the directly bound EIP takes precedence over the NAT Gateway's EIP.

The NAT Gateway provides SNAT and DNAT capabilities, allowing multiple Baidu Cloud Compute instances to share a single EIP.

Baidu Cloud Compute binds an EIP directly in exclusive IP mode.

• SNAT: When both SNAT and EIP binding are configured on the same BCC, the BCC prioritizes the directly bound EIP for outbound public IP traffic.
• DNAT: When the same BCC has both DNAT configured and an EIP bound, inbound access via the DNAT EIP will fail because the BCC prioritizes the directly bound EIP for egress traffic, resulting in inconsistent ingress and egress EIPs.