2006-10-29 GRE tunnel 関連 cisco http://www.cisco.com/japanese/warp/public/3/jp/service/tac/original/router_guide/gre_overipsec_dynamic_routing.shtml http://www.cisco.com/japanese/warp/public/3/jp/service/tac/original/router_guide/dmvpn_ipsec_vpn.shtml http://www.securityfocus.com/infocus/1847