When Chloe gives jack the IP address in the secure comms room she gives him 2.718.281.828
She gives him an IPv4 address which is 4 blocks of numbers from 0 - 255 so the last 3 blocks given are not valid and will not work (possibly done this way so people would not try to access the IP)
IPv4 addresses are between 0.0.0.0 and 255.255.255.255 IPv6 addresses are between 0:0:0:0:0:0:0:0 and FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF.
She gives him an IPv4 address which is 4 blocks of numbers from 0 - 255 so the last 3 blocks given are not valid and will not work (possibly done this way so people would not try to access the IP)
IPv4 addresses are between 0.0.0.0 and 255.255.255.255 IPv6 addresses are between 0:0:0:0:0:0:0:0 and FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF.