Netis DL4311 User Manual page 56

ADSL2+ Modem Router User Manual
If the FTP server listen the port on 2100, you can add a FTP ALG port 2100 on the device.
4.3.2.7 Nat IP Mapping:
NAT IP mapping allows you to configure one IP pool for specified source IP address from LAN,
so a packet whose source IP is in range of the specified address will select one IP address
from pool for NAT.
Choose Advanced->NAT->NAT IP Mapping page, you can configure the mapping rules.
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