H3C S5120-SI Series Command Reference Manual page 213

mask: Subnet mask in dotted decimal notation.
mask-length: Subnet mask length, the number of consecutive ones in the mask.
Description
Use the ip address command to assign an IP address and mask to the interface.
Use the undo ip address command to remove all IP addresses from the interface.
By default, no IP address is assigned to any interface.
Related commands: display ip interface.
Examples
# Assign VLAN-interface 1 a primary IP address 129.12.0.1, with subnet masks being 255.255.255.0.
<Sysname> system-view
[Sysname] interface vlan-interface 1
[Sysname-Vlan-interface1] ip address 129.12.0.1 255.255.255.0
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