are there circumstances where a cookie gets removed by the load balancer?

should not. passthrough = no ssl profiles on the BIGIP? Then no way it could remove a cookie... the BIGIP do not decrypt SSL in that case and cannot "see" any HTTP passing through.

 

Maybe your issue is that the backend sets a domain for the cookie and it doesn't corresponds to the URL in client's browser. I suggest a HTTP trace in your browser to see what cookie the app is setting.

 

If you're using SSL passthrough (Presumably he has encryption enabled and not using one of the NULL encryption suites), then no. He gets it all or the stream breaks.

 

H

 

additional information - it works fine in firefox but not in IE 11 compatibility mode.