Next if the Set-Cookie from the server includes a Domain=value the Client HTTP Host: header value must match the Set-Cookie Domain= value.
Server sets a cookie with the client:
Set-Cookie: wrhttpservercookie=123456; Expires=Thu, 01 Jan 2015 00:00:00 GMT; Path=/path; Domain=192.168.1.1
The client does not send back this cookie in subsequent requests when using a domain as the Host: header does not match the Domain value of 192.168.1.1
Client header example for the above:
To resolve the Domain must ether be set the same as the Client Host header or the Client Host header will need to use the IP value.
The client HTTP Host: header is set based on the GET line in the Client/Actions list
1 GET http://192.168.1.1/path/somepage.html
#Host header will be Host: 192.168.1.1 for this request
1 GET https://www.spirent.com/path/somepage.html
#Host header will be Host: www.spirent.com for this request
For the server Set-Cookie Domain value this would be set on the Server/Transaction Additional Header field.
More information on HTTP cookies can be found in RFC 6265