This topic lists the network requirements on the on-premises data center when you use Express Connect to connect the on-premises data center with Alibaba Cloud.

  • If you choose to use an optical port, you must use a single-mode optical module of the following types to connect to the access device of Alibaba Cloud, and make sure that the settings of the optical modules at both ends are consistent.
    • 1 GB Ethernet 1000Base-LX single-mode optical module
    • 10 GB Ethernet 10GBase-LR single-mode optical module
    • 40 GB Ethernet 40GBase-LR single-mode optical module
    • 100 GB Ethernet 100GBase-LR single-mode optical module
  • The auto-negotiation function of the port must be disabled. You must manually configure the port speed and use the full duplex mode.
  • The entire connection, including intermediate devices, must support 802.1Q VLAN encapsulation.
  • The network device at your on-premises data center must support Border Gateway Protocol (BGP) and BGP MD5 authentication, or static routing.
  • If you use redundant physical connections, make sure that route weights can be set on the network devices.
  • Optional. You can configure Bidirectional Forwarding Detection (BFD) on the network.
  • The Maximum Transmission Unit (MTU) supported at the physical connection layer is 1522 bytes: 14-byte Ethernet header + 4-byte VLAN flag + 1500-byte IP datagram + 4-byte FCS. Recommended value: 1500.
  • We recommend that you use private IP addresses for the connection between the on-premises data center and Alibaba Cloud. The CIDR blocks used for the connection cannot conflict with each other.
  • To avoid conflict with the cloud service address, the network connected with Alibaba Cloud cannot use the CIDR block 100.64.0.0/12.