[network/front door] Error message indicating invalid IP address is wrong


Either this message should be changed, or one should be able to deploy using arbitrary IPv4 addresses. Opening here because it seems to be a backend issue, it happens in both Portal and CLI.

Start with the network/front door issue and the attached error screenshot, then compare the behavior in the Portal and CLI. No file or test is named; trace the backend validation that produces the invalid-IP message. Done means the message accurately reflects the accepted IPv4 addresses or arbitrary IPv4 deployment works.

Written by the indexing model from the issue text.