Windows CA does allow issuing to IP addresses for the subject name. What you would probably want to do is to issue the certificate using a Subject Alternative Name (SAN). Basically you choose one name for the subject for the CSR, then when you submit to the certsrv page you use the Attributes field to include DNS=
www.domain.com&IP=192. 168.0.1&DN S=hostname
Note that you need SAN enabled on the CA for this to work. Refer to this document for more info:
http://support.microsoft.c om/kb/9313 51
If you are using public certs, consider a Unified Communications Certificate (UCC or UC Cert), sometimes referred to as multi-domain certificate. Pretty much the same thing - you submit the CSR and then they provide a text field where you can just type in on separate lines what you want to be valid - these can be hostnames, IP addresses, DNS names/aliases, etc. They cost a bit more but worth it when you need one. Most commercial CAs will offer these (Verisign, Comodo, GoDaddy, etc.).