A network in which a client receives a network credential, such as a valid network address, following an exchange of messages with a credential server that includes security information. The security information may validate the credential, avoiding rogue devices inadvertently or maliciously distributing credential information that can interfere with clients attempting to connect to the network or with the network itself. If obtaining a network credential requires an exchange of information about the configuration of the client that could reveal security vulnerabilities, the security information may be used to ensure the confidentiality of that configuration information. The security information may be incorporated into messages according to a known protocol, such as by incorporating it into options fields of DHCP messages.