404 error while integrating Webseal for Sharepoint dev url

Hi All

We are unable to access SharePoint if traffic passes through web seal ,well it was fine with WFE ip and F5 ip directly if we made changes at local hosts

WFE ------------------->10.XXX.XX.XX 

Web Seal server --->10.XXX.XXX.XX  

 F5--------------------->10.XXX.XXX.XX

• <Host entries> made to point      directly toWFE of SharePoint10.XXX.XX.XX        collaboration.unit.xdomain.net

Navigate tohttps://collaboration.unit.xdomain.net/sites/portal

Site resolves correctly:  able to load site with account with permissions one test and resolve the standard “Sorry, this site hasn't been shared with you.” Message on browser not using account with permissions

• <Host entries> made to point      directly toWebseal server10.XXX.XXX.XX          collaboration.unit.xdomain.net

Navigate tohttps://collaboration.unit.xdomain.net/sites/portal

URL changes tohttps://auth.unit.xdomain.net/pkmsvouchfor?americas&https://collaboration.unit.xdomain.net/sites/portal

Server registers 401

Continuous prompt for authentication from both test systems

No site resolution

• <Host entries> made to point      directly toF5 at 10.XXX.XXX.XX                                collaboration.unit.xdomain.net

Navigate tohttps://collaboration.unit.xdomain.net/sites/portal

Site resolves correctly:  able to load site with account with permissions one test and resolve the standard “Sorry, this site hasn't been shared with you.” Message on browser not using account with permissions

Sashank