I believe that there should be no differences between WebUI to RESTAPI when adding IP related details. Today we need to add <ip address='' netmask='' gateway=''> to logical network in order to have an IP configuration when attaching network to nic. This is a wrong approach! 1. attaching the same network to different hosts in the same cluster should have the same ip? 2. adding IP would be under logical network but edit IP would be under host_nic? So the thing is, under logical network we should have only <name>, <description>, <vlan> and <stp>. Host_nic will be the place where we need to handle <ip> and <boot_protocol> while attaching network to host's nic and also when updating host's nic. BTW, SetupNetworks which is under host_nics actually accept <ip> and <boot_protocol> when attaching host's nics.
Closing old bugs. If this issue is still relevant/important in current version, please re-open the bug.