Open Transport 1.3 — Mac OS 8.1 includes Open Transport 1.3, an update to Apple’s networking software. OT 1.3 offers general performance improvements, better recognition of serial ports – particularly in conjunction with PC Card modems – and numerous tweaks and bug fixes. What’s new and exciting about OT 1.3 is single-link multihoming, which enables a Mac’s Ethernet hardware to respond to more than one IP address simultaneously (for example, a server can more easily serve multiple Web sites, each having its own domain name). Previously, this functionality was only available on Macs via MkLinux, WebTen, or other Unix-like products. Although users who use modems to access the Internet won’t much care about single-link multihoming, it can be critically important to Internet service providers who host Internet servers on Macs.
Administrators configure single-link multihoming via a text file called IP Secondary Addresses stored in the Preferences folder – the exact format is included in OT 1.3’s Technical Info document. However, just because OT supports multiple IP addresses doesn’t mean Internet applications do, and most Internet server applications must be revised to offer direct support. (QuidProQuo 2.1 and the public beta of WebSTAR 3.0 already do.) Although single-link multihoming is a new and welcome capability, it doesn’t put alternatives like HomeDoor and ClearlyHome out of business; OT 1.3 assumes administrators have IP addresses to spare and lacks some of the special features of these add-on products. [GD]