For reasons to many to bring up here, we are trying access a Portal for ArcGIS web adapter using IIS Application Request Routing setup on two load balanced web servers. The web adapter is installed on an internal web server, and the ARR rules are configured on public facing external servers. The issue we are having is that when the request reaches the Portal, we receive a 302 URL Redirect that drops the ARR route value, which causes a 404 not found error.
This is the notional URL pattern using the ARR rule: https://oursite.com/redirect/PortalWebAdapter
This is the response from the 302 redirect https://oursite.com/PortalWebAdapter/home
We know we can avoid using ARR by installing the web adapter on the public facing systems, but only one web adapter can be associated with Portal and we need to have two for the load balanced web servers.
This is actually something my colleagues and I just came across. What we found is the default URL Rewrite in ARR is set to redirect traffic to http://
To avoid the 302 Loop in our environment we had to update the URL Rewrite rule to redirect to https://. Once we did this the 302 Loop was avoided.
The other thing that we found we could do to avoid this was to complete the following:
(1) Log into the portaladmin
(2) Click on System
(3) Click on Web Adaptors
(4) Click on oursite.domain.com hyperlink
(5) In the address bar append /edit to the URL
(6) Update the Web Adaptor URL so that it's using the DNS alias for the Portal site. Typically this is defaulted to the internal name of the server when the web adaptor was first configured.
Essentially this will white-list the URL for Portal and will prevent the 302 Loop as well.
I hope this information helps.