Restricting the IP address of the IPv4 explicit web proxy
You can use the following command to restrict access to the explicit web proxy using only one IP address. The IP address that you specify must be the IP address of an interface that the explicit HTTP proxy is enabled on. You might want to use this option if the explicit FTP proxy is enabled on an interface with multiple IP addresses.
For example, to require uses to connect to the IP address 10.31.101.100 to connect to the explicit HTTP proxy:
config web-proxy explicit
set incoming-ip 10.31.101.100
end