NLB IIS 6.0 .NET ASP Web Application, URL Randomly Changing from Hostname to IP

[James M via .NET 247]

(I have 2x Front-end Web servers (Win2003 Ent IIS6.0), setup withNLB (single Affinity, also using SQLServer session state) thatare hosting a few .NET ASP web applications under the DefaultWebsite in IIS, and accessing via a Intranet LAN (this is notpublicly available).

NETWEB1:
NIC1 172.16.17.220
172.16.17.244 (NLB Virtual IP)

NIC2 172.16.17.221


NETWEB2:
NIC1 172.16.17.222
172.16.17.244 (NLB Virtual IP)

NIC2 172.16.17.223


I'm using the following code in my .NET ASP web applications forall links on the webpages:

urlSuffix = Context.Request.Url.Host &Context.Request.ApplicationPath
pageUrlBase = "http://" & urlSuffix


The problem is... (referring to a session running on NETWEB1)...

Using Virtual Hostname FQDN (http://nlb.domain.com): Randomly,the a link will change from the NLB Virtual Hostname to the NLBVirtual IP address, and clicking on the link will start a newsession, requiring re-login (the URL is nowhttp://172.16.17.244).

Using Virtual Hostname (http://nlb): Randomly, the a link willchange from the NLB Virtual Hostname to the Non-NLB Server IPaddress, and clicking on the link will start a new session,requiring re-login (the URL becomes http://172.16.17.221).


This seems to be completely random in timing, but does happenafter a few minutes of navigating around the website.

Any Ideas???