'get vpn instance name'

def get_interface_vpn_name(self, vpninfo, vpn_name):

    l3vpn_if = vpninfo.findall('l3vpnIf')
    for l3vpn_ifinfo in l3vpn_if:
        for ele in l3vpn_ifinfo:
            if (ele.tag in ['ifName']):
                if (ele.text == self.vpn_interface):
                    self.intf_info['vrfName'] = vpn_name
