Patches and updates
ArcView Network Analyst 1.0b Update for Windows
ArcView Network Analyst Version 1.0b is an update to ArcView Network Analyst 1.0/1.0a. This update resolves a problem where the FNODE_/TNODE_ fields in ARC/INFO coverages were incorrectly used in some cases. You must already have ArcView Network Analyst Version 1.0/1.0a to use this installation.
Note for ArcView GIS Version 3.1 users with Network Analyst already installed: this update is included in the ArcView GIS Version 3.1 install, and the update to Network Analyst 1.0b is automatic. The update addresses the above problem as well as provides support for routing on shapes with measures and z-coordinates. If you installed Network Analyst 1.0a after installing ArcView GIS 3.1, you can run the ArcView GIS Version 3.1 install again to update Network Analyst.