Network class

What is the MTU value supported by BCC?

Currently, the default MTU (Maximum Transmission Unit) value for both Intranet and Internet cards is 1500. You can refer to the following commands to query the current MTU setting value:

• Linux: Run the "netstat -i" command to check.

• Windows: Run the command "netsh interface ip show interface" in cmd to check.

If large files are fragmented during transmission, it could be caused by a high MTU setting value. The solution is to lower the machine's MTU value. For instance, to adjust the MTU value for API eth0, use the following command (xxxx represents the desired MTU value):

1ip link set dev eth0 mtu xxxx

How to create a BCC with a public IP?

An EIP must be bound to the BCC to access the public network using the EIP.

Is the public IP assigned by BCC to users unique?

When purchasing BCC, you can associate and purchase an EIP, which will automatically assign a unique, dedicated, and fixed public IP to the user.

Is the external IP address fixed?

Correct, users are not allowed to specify, select, or purchase additional public IP addresses for cloud servers.

What is the difference between a BCC public IP and a private IP?

When buying BCC, you can associate and purchase an EIP. The EIP will be automatically bound to the BCC, with the system assigning a public IP to the corresponding EIP.

• Public IPs are essential for connecting to the public network. If a server application needs to be accessed externally via the public network, a public IP is required.
• Private IPs enable communication between multiple cloud servers within a private network. If your account includes several cloud servers, private IPs facilitate data transmission between servers. The performance of private network transmission depends on parameters like bandwidth and packet rate specified in the instance's specifications.

How to access from the Internet if there is no public IP?

You must have at least one BCC capable of connecting to the public network. Use this cloud server as a relay to connect BCCs without a public IP through a virtual private cloud.

How to upgrade the public network bandwidth?

For each EIP instance, you can adjust the bandwidth according to actual needs. For prepaid EIP instances, only bandwidth upgrades are supported, and downgrades are not supported. For postpaid EIP instances, the bandwidth can be adjusted at any time in the console. For operation documentation, please refer to Upgrade EIP Instance Bandwidth.

Can the public IP be released?

Users can release the idle EIP instances to save costs, except in the following three circumstances:

• Subscribed EIP instances not expired
• EIP already bound to BCC or BLB instances
• EIP suspended due to attacks

To release a subscribed EIP instance not expired, submit a financial ticket to request a refund. Whether a refund is permitted will be determined by the ticket resolution result.

How does BCC bind dual public IPs?

BCC supports binding to elastic network interfaces, enabling multiple public and intranet IPs on a single BCC instance. For details, please refer to the Elastic Network Interface Document.

What is the regional network line?

We currently provide BGP multi-line access, interfacing with operators such as China Unicom, China Telecom, China Mobile, and CERNET.

Is the bandwidth dedicated?

Yes, it is exclusively dedicated.

Can users manually change the server IP address after BCC creation? Is it possible to bind the server to my own public IP by myself?

The BCC's public IP is mapped to the server's internal IP through multiple conversions. Modifying the network settings of a cloud server manually may lead to issues such as server inaccessibility.

BCC supports on-demand changes to intranet IP addresses, which can be operated on the Instance List page in the console.

If an Internet service such as Apache or MySQL is deployed on BCC, how to bind the listener port to an IP address to publish the service?

To deploy Internet services on a BCC, bind the listener port to the intranet address or 0.0.0.0 to make the service available. Clients of services on BCC access the service using the public IP.

For example, if a BCC instance has a public IP of 180.76.135.xxx and an intranet IP of 192.168.xxx.xxx, and Apache service is deployed on this BCC instance, the configuration in the configuration file should be as follows:

Listen 0.0.0.0:80 Listen 0.0.0.0:8080

Or: Listen 192.168.xxx.xxx:80 Listen 192.168.xxx.xxx:8080

Once published, open a browser and visit http://180.76.135.xxx:80 to view the page service hosted on the BCC instance.

How can BCC instances under different accounts achieve intranet intercommunication?

By default, cloud servers within the same VPC (Virtual Private Cloud) can communicate with each other via the internal network, while cloud servers in different VPCs are isolated. For communication, you can activate the peering connection service to achieve high-speed interconnection between VPCs. For details, please refer to the Peering Connection Document.

Why can't some ports be used normally?

The Baidu Cloud Compute (BCC) has no restrictions on ports. You need to check the following:

1. Does the firewall and security group allow this port?
2. Is the service listening to this port normally?
   Only when both conditions are met can the port be considered normal.

What are the reasons for increased network latency/intermittent packet loss?

Various factors can lead to increased network latency or packet loss, such as physical line issues with the network service provider, fluctuations in network traffic, or accessing different resource nodes. If network issues occur, submit the IP address via a ticket for investigation.

How to do if there is packet loss when pinging a website?

First, check if there is any latency when pinging the Internet (e.g., ping baidu.com).

• If there are issues when pinging other external websites, it is likely a problem with your local network or your broadband service provider;
• If there are no issues when pinging other external websites, please check whether the bandwidth of the cloud server you are using is fully utilized. If not, execute the trace route command on the IP address of the virtual machine: use the traceroute <IP> command in a Linux environment and the tracert <IP> command in Windows.

Note: Replace <IP> with the corresponding IP address. You can view which IP nodes are experiencing delays or timeouts based on the route tracing results and confirm the ownership of these IPs. Alternatively, you can submit a ticket to contact technical personnel and upload the output of the ping command and the traceroute/tracert command to the ticket for Baidu technical personnel to analyze the cause.

Why is website browsing abnormal on a windows cloud server?

On BCC, the Windows server version comes with IE enhanced security configuration enabled by default for safety reasons. Add relevant sites to the trusted sites list for normal access or disable the Internet Explorer Enhanced Security Configuration.

• For Windows Server 2008: Change the IE ESC (Enhanced Security Configuration) setting to "Disabled" in Management Tool - Server Manager - Server Summary - Security Information.
• For Windows Server 2012: Modify the Internet Explorer Enhanced Security Configuration setting to "Disabled" via Management Tool - Server Manager - Local Server - Attributes.