d-i apt-setup/uri_type http
  d-i apt-setup/hostname string 192.168.1.6
  d-i apt-setup/directory string /~kgraham/mirrors/archive.ubuntu.com/ubuntu
  d-i apt-setup/another boolean false
  d-i apt-setup/security-updates true
  d-i apt-setup/services-select multiselect security
  d-i apt-setup/security_host string 192.168.1.6
 d-i apt-setup/security_path string /~kgraham/mirrors/security.ubuntu.com/ubuntu

d-i mirror/country string US
d-i mirror/http/hostname string 192.168.1.6
d-i mirror/http/directory string /~kgraham/mirrors/archive.ubuntu.com/ubuntu/
d-i mirror/http/proxy string