The old AJAX and Home Automation Dashboard local interfaces which were built into IoX on the ISY 994 are still present on the EISY (at least in version 5.7.1). They have been deprecated and may be removed with any future updates, and some options are not functional (for example, the admin console doesn't seem to open from the UD AJAX interface). Basic control of devices, scenes, programs and variables seems to work, at least for Insteon devices.
On the EISY, http and https ports have been moved from default 80 and 443 to 8080 and 8443 respectively. In addition, the mapping of a default web page has been eliminated, so the exact URL to the desired page has to be specified. They can be accessed at the ip address of the EISY, or alternatively at eisy.local if the EISY is properly registering its name.
EISY Local URLS include:
UD AJAX interface: http://xxx.xxx.xxx.xxx:8080/WEB/udajax.htm or https://xxx.xxx.xxx.xxx:8443/WEB/udajax.htm
Home Automation Dashboard interface:
http://xxx.xxx.xxx.xxx:8080/WEB/HAD.htm or https://xxx.xxx.xxx.xxx:8443/WEB/HAD.htm
You can also download the appropriate admin console for your version from the EISY at:
https://xxx.xxx.xxx.xxx:8443/WEB/admin.jnlp
or access your local Polyglot server at:
https://xxx.xxx.xxx.xxx:3000
Michel resolved this issue through a support ticket. TLDR: It was a network issue
My 994i was always located out in my (heated) barn, since that is where the majority of my Insteon devices are. I originally started using Insteon to control the various lights and doors in the barn so that I wouldn't have to run a bunch of switch legs back to the house. The barn has a CAT5 run (about 100 feet) from my house network with a 8 port switch on it, and various other network connected gear. The 994 worked fine on it, as do my other items out there (Roku, laptop, etc.)
The EISY must be more particular about its network connection, or there is some kind of issue with that network run or switch. Including the barn switch, the EISY was two hops from my main router, which is another two hops from the internet. The EISY couldn't communicate through that many hops, or at least through that particular connection. When I brought the EISY into the house and plugged it directly into the router, everything works fine.
FYI for anyone else who is suffering from this, the symptoms were that the EISY would not synchronize its time, my Polyglot Dashboard wouldn't launch, and I couldn't SSH into the system. I could talk to it fine through Admin Console and UDMobile could connect and sync. IoX launcher found it without a problem, and the EISY got a reserved IP address through DHCP and reliably registered eisy.local with the router. Since the EISY responded on the network in many ways, and it was literally a plug and play installation of where I had the 994 installed, I didn't think that it could be a network issue. Relocating the EISY proved that this was the problem.
