def METHOD_NAME(router_name):
    "Return a dict with link state id as key and forwarding addresses as value"
    result = dict()
    tgen = get_topogen()
    router = tgen.gears[router_name]
    cmd = "show ip ospf database external\n"
    output = topotest.normalize_text(router.vtysh_cmd(cmd))
    for line in output.splitlines():
        re0 = re.match(r"\s+Link State ID: (\S+) \(External Network Number\)", line)
        if re0:
            lsa = re0.group(1)
        re1 = re.match(r"\s+Forward Address: (\S+)", line)
        if re1:
            result[lsa] = re1.group(1)
    return result