Compex Technologies NP25G 6C - Manual (Page 44)

Page 39
DHCP Lease Time
This is the length of time that the client may use
the assigned address before having to check with
the DHCP server to see if the Address is still valid.
Always use these DNS
servers
Enable this checkbox if you only want to use the
DNS server(s) you have specified.
Primary DNS IP Address
Your ISP usually provides the IP address of the DNS
server.
Secondary DNS IP Address
This optional setting is the IP address of a
secondary DNS server.