Virtual Lane Independence Through IP Subnetting

Language:

VL independence is enforced through IP networking by creating two separate IP subnets for each datacenter and one IP subnet for communication between the two datacenters.

For example, assume datacenter 1 has subnets A and B, and datacenter 2 has subnets C and D, and subnet E is the communication subnet between the two datacenters.

Within each datacenter, hosts and virtualization switches have their own IP subnet, as shown in the following illustration.

image:Illustration shows the IP subnets for hosts and virtualization switches within each datacenter.

No.	Description
1	Datacenter (shaded top area) consisting of hosts, leaf switches, and virtualization switches.
2	Datacenter (shaded bottom area) consisting of hosts, leaf switches, and virtualization switches.
3	IP Subnet, hosts (Subnet A) One IP subnet for the hosts maps to an IPoIB link in partition A and can be associated with SL2. The IP subnet for hosts is used for communication among the hosts in one datacenter.
4	IP Subnet, virtualization switches (Subnet B) One IP subnet for the virtualization switches maps to an IPoIB link in partition B and can be associated with SL3. The IP subnet for virtualization switches is used for communication between the pair of virtualization switches in one datacenter. If communication between virtualization switches is not required, these subnets can be left undefined.
5.	IP Subnet, hosts (Subnet C) One IP subnet for the hosts in the second datacenter maps to an IPoIB link in partition C and can be associated with SL2. This subnet is conceptually the same as datacenter 1, but the IP subnet and partition key must be unique to the second datacenter.
6.	IP Subnet, virtualization switches (Subnet D) One IP subnet for the virtualization switches in the second datacenter maps to an IPoIB link in partition D and can be associated with SL3. This subnet is conceptually the same as datacenter 1, but the IP subnet and partition key must be unique to the second datacenter.

Between both datacenters, hosts in different datacenters can communicate over the single communication subnet as shown in the following illustration.

image:Illustration shows the common subnet that enables host communication between the two datacenters.

No.	Description
1	Datacenter (shaded top area) consisting of hosts, leaf switches, and virtualization switches.
2	Datacenter (shaded bottom area) consisting of hosts, leaf switches, and virtualization switches.
3	IP Subnet, common subnet for host communication between datacenters (Subnet E) One IP subnet maps to an IPoIB link in partition E associated with SL0.