def METHOD_NAME(mod):
    "Sets up the pytest environment"
    # Required linux kernel version for this suite to run.
    result = required_linux_kernel_version("5.0")
    if result is not True:
        pytest.skip("Kernel requirements are not met")
    tgen = Topogen(build_topo, mod.__name__)
    tgen.start_topology()
    router_list = tgen.routers()
    logger.info("Testing with VRF Lite support")
    cmds = [
        "ip link add {0}-cust1 type vrf table 1001",
        "ip link add loop1 type dummy",
        "ip link set loop1 master {0}-cust1",
        "ip link set {0}-eth0 master {0}-cust1",
    ]
    for rname, router in router_list.items():
        for cmd in cmds:
            output = tgen.net[rname].cmd(cmd.format(rname))
    for rname, router in router_list.items():
        router.load_config(
            TopoRouter.RD_ZEBRA, os.path.join(CWD, "{}/zebra.conf".format(rname))
        )
        router.load_config(
            TopoRouter.RD_BGP, os.path.join(CWD, "{}/bgpd.conf".format(rname))
        )
    # Initialize all routers.
    tgen.start_router()