Aqui está um exemplo:
frontend http
bind 0.0.0.0:80
default_backend www
# NAT static host names and static paths in other hostnames to a different backend
acl host_static hdr_beg(host) -i static.
acl url_static path_beg /static
use_backend static if host_static or url_static
backend www
balance roundrobin
server qa1 10.177.1.81:80
server qa2 10.177.1.45:80
backend static
balance roundrobin
server media1 10.177.0.86:80