{
    "name"  : "内网是否使用NAT设备",
    "problems" : {
        "nat" : {
            "desc"      : "【问题】用户IP流量未到达设备",
            "advice"    : "【建议】请检查内网是否使用NAT设备，可能导致会话限制异常"
        }
    }
}
---------------------------code-------------------------------
userNoNetIp = precondition('userNoNetIp')
cmd = "show ip f f | in " + userNoNetIp
response = cli(cmd)
results = response.split(/\r?\n/)

if results.length == 2:
    add_problem("nat")
    return "warn"
end

return "success"
