一般是在已經啟動的交換機級聯的時候才需要修改domainID，因為級聯的時候交換機會從上游upstream（domainID小的那台）更新到下游downstream（domainID大的那台），所以下游的交換機（也就是要修改domainID的交換機，因為交換機啟動的時候沒有接入網絡默認domainID為1）必須要向做備份configUpload，否則配置會被上游的交換機更改。
先禁用交換機
switchDisable
進入configure ，看到Fabric parameters時輸入y，就可以修改domainID
swd78:admin> configure
Configure...
Fabric parameters (yes, y, no, n): [no] y
Domain: (1..239) [1] 2
之后可以一直回車選擇默認的配置，也可以Ctrl+ D直接跳過
R_A_TOV: (4000..120000) [10000]
E_D_TOV: (1000..5000) [2000]
WAN_TOV: (0..30000) [0]
MAX_HOPS: (7..19) [7]
Data field size: (256..2112) [2112]
Sequence Level Switching: (0..1) [0]
Disable Device Probing: (0..1) [0]
Suppress Class F Traffic: (0..1) [0]
Switch PID Format: (1..2) [1]
Per-frame Route Priority: (0..1) [0]
Long Distance Fabric: (0..1) [0]
BB credit: (1..27) [16]Insistent Domain ID Mode (yes, y, no, n): [no]
Virtual Channel parameters (yes, y, no, n): [no]
Zoning Operation parameters (yes, y, no, n): [no]
RSCN Transmission Mode (yes, y, no, n): [no]
Arbitrated Loop parameters (yes, y, no, n): [no]
System services (yes, y, no, n): [no]
Portlog events enable (yes, y, no, n): [no]
ssl attributes (yes, y, no, n): [no]
http attributes (yes, y, no, n): [no]
snmp attributes (yes, y, no, n): [no]
rpcd attributes (yes, y, no, n): [no]
cfgload attributes (yes, y, no, n): [no]
WARNING: The domain ID will be changed. The port level zoning may be affected
然后就啟動交換機
switchEnable