Notes and Constraints

Quotas

Restrictions on Locations

Before creating a connection, you need to select a location. Note the following restrictions:

• There may be more than one location in each region. In this case, network latency from each location to different AZs in the region should be less than 5 ms.
• If your workloads have demanding requirements for network latency, you can submit a service ticket to confirm which location is the nearest to the AZ where your cloud servers are running.

For details about the locations in each region, see Direct Connect Locations.

Product Use Restrictions

• The CIDR block of the VPC cannot overlap with the CIDR block used by the on-premises network.

  The on-premises network cannot use 100.64.0.0/10, 127.0.0.0/8, 169.254.0.0/16, and 224.0.0.0/3 because they are reserved for the VPC service.

• 1GE and 10GE single-mode optical ports can transmit data up to 10 km. If you need an optical port to transmit data for more than 10 km, or you need a 40GE or 100GE port, you need to purchase optical modules by yourself. For suggestions on optical module selection, submit a service ticket.
• If you use a Direct Connect connection to access ELB, you must select Source IP hash as the load balancing algorithm and disable sticky sessions for ELB.
• Direct Connect can respond to common ICMP packets (echo packets whose type is 8 and code is 0 and do not carry IP options) for ping detections.
• For each connection, a maximum of 30 ping detections can be performed on the local gateway IP address over the port per second.
• To connect on-premises data centers through enterprise routers, ensure that the on-premises data centers are connected to different devices. For details, see submit a service ticket.
• A virtual gateway can be associated with only two different devices.

Network Requirements

• Your on-premises network must use a single-mode fiber with a 1GE, 10GE, 40GE, or 100GE optical module to connect to the access device on Huawei Cloud. In addition, key parameters such as the LC, wavelength, and distance must be consistent with those of the access device on Huawei Cloud. Examples of optical module parameters: 1 GE, LC single-mode, 1,310 nm, and 10 km
• Auto-negotiation for the ports must be disabled. Port speed and full-duplex mode must be manually configured.
• 802.1Q VLAN encapsulation must be supported on all devices of the entire connection, including intermediate devices.
• Your device must support Border Gateway Protocol (BGP) and BGP MD5 authentication or static routing.
• (Optional) You can configure Bidirectional Forwarding Detection (BFD) on the network.
• A physical connection supports jumbo frames with a default maximum transmission unit (MTU) size of 8,500 bytes. If you need to configure a larger MTU, contact the Direct Connect manager.

  If you ping the IP address of the local gateway of a Direct Connect connection for connectivity test, the MTU is 1,500 bytes.

• Private IP addresses are recommended for cloud and on-premises servers, and the IP address ranges used for communications cannot overlap.

Construction Notes

• Your construction company must comply with the regulations presented by the equipment room provider and engineers. In case of any violation, the construction cannot be completed.
• No optical-to-electrical converters can be hosted or installed in the equipment room.
• Network blocking due to state policies or Huawei Cloud management will delay the construction. In the event of such situation, contact your Direct Connect manager.
• The equipment room at a location is operated by a telecom carrier or a third party. If there are fees for connecting your leased line to the equipment room or an in-building cable, pay the fees to the equipment room provider.
• You need to apply for a Letter of Authorization (LOA) and present the LOA when entering the equipment room for construction.