H3C Technologies H3C S5830V2 Series Switches - Manual (Page 52)

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of the principal switch carried in the packet against those locally recorded. The switch replaces the
locally-recorded principal switch information with the principal switch information recorded in the
packet and notifies the other switches when any of the following conditions is true:
{
The priority carried in the packet is higher.
{
The priority in the packet is the same and the WWN is smaller.
Finally, all switches in the network make an agreement on the principal switch.
3. When the PSST times out, if the locally-recorded principal switch information is the local switch, the
switch becomes the principal switch.
After the principal switch is selected, the WWN of the principal switch becomes the fabric name.
NOTE:
During the principal switch selection process, if a switch receives a packet that updates the principal switch
information, the switch must record the E_Port receiving the packet. The link relevant to this E_Port is called
the "upstream principal link."
Domain ID assignment
A domain represents a switch and all N_Ports connected to the switch. Each domain must have a domain
ID.
Domain IDs can be manually configured or automatically assigned for FC switches.
• When you manually configure static domain IDs, you must assign a unique domain ID to each
switch in the fabric.
• When domain IDs are dynamically assigned, the fabric configuration process is performed to select
a principal switch and assign domain IDs. After the principal switch is selected, the principal switch
assigns domain IDs to all switches in the fabric. After the fabric configuration process, each switch
has a unique domain ID.
The dynamic domain ID assignment process is as follows:
1. The principal switch assigns a domain ID to itself:
{
If the principal switch has been configured with a desired domain ID, the principal switch
assigns the domain ID to itself.
{
If the principal switch is not configured with a desired domain ID, the principal switch assigns
the smallest available domain ID to itself.
2. After the principal switch assigns a domain ID to itself, it notifies its downstream switches to request
domain IDs from it.
3. After a downstream switch receives the notification, it starts to request a domain ID from the
principal switch.
If the downstream switch is configured with a desired domain ID, it requests the desired domain ID
from the principal switch.
4. After the principal switch receives the domain ID request from the downstream switch, it assigns a
domain ID to it and notifies the downstream switch.
The principal switch assigns domain IDs following these rules:
{
If the downstream switch requests a desired domain ID that is available, the principal switch
assigns the domain ID to the downstream switch.