Because they are by default made use of in the hash-essential lookup, any modify in the cookies shopper-aspect will result in a different hash and a new object in the cache. To help Varnish, it is most effective to redirect users to a single domain and not retain multiple achievable domains that would consequence in the exact same articles being generated. Varnish features an appealing VMOD (extension to Varnish) to help manipulate Cookies.