IT-Sichereitsaspekte in heterognen Netzwerken
2.1 2.2 2.3 2.4 TCP/IP-R EFERENZMODELL ............................................................................................................................ 7 Z IELE DER IT-S ICHERHEIT ................................................................................................................................ 9 B EDROHUNGEN DER IT-S ICHERHEIT ............................................................................................................... 10 M AßNAHMEN DER IT-S ICHERHEIT .................................................................................................................. 10 KAPITEL 3 3.1 3.2 3.3 3.4 3.5 M EDIENZUGRIFF ......................................................................................................................................... 12 A DRESSIERUNG IM E THERNET ....................................................................................................................... 13 S ICHERHEITSASPEKTE IM E THERNET ................................................................................................................ 15 VLAN - V IRTUAL LAN ................................................................................................................................. 16 IEEE 802.1X ............................................................................................................................................ 18 KAPITEL 4 4.1 4.2 4.3 ETHERNET ................................................................................................................................12 WIRELESS LAN ..........................................................................................................................20 T ECHNISCHE G RUNDLAGEN .......................................................................................................................... 20 WLAN-K OMPONENTEN .............................................................................................................................. 21 WLAN-S ICHERHEIT .................................................................................................................................... 22 KAPITEL 5 NETZWERK-TOOLS....................................................................................................................24 5.1 N ETZWERK -T OOLS UNTER W INDOWS ............................................................................................................. 25 5.1.1 ARP ................................................................................................................................................ 25 5.1.2 Hostname ...................................................................................................................................... 27 5.1.3 Ipconfig .......................................................................................................................................... 27 5.1.4 NBTSTAT ........................................................................................................................................ 30 5.1.5 netstat, .......................................................................................................................................... 31 5.1.6 nslookup ........................................................................................................................................ 33 5.1.7 ping und pathping.......................................................................................................................... 34 5.1.8 traceroute/tracert.......................................................................................................................... 35 5.2 N ETZWERK -T OOLS UNTER L INUX ................................................................................................................... 36 5.2.1 ifconfig. .......................................................................................................................................... 36 5.2.2 route .............................................................................................................................................. 36 5.2.3 ping ................................................................................................................................................ 37 5.2.4 traceroute ...................................................................................................................................... 37 5.2.5 netstat ........................................................................................................................................... 37 5.2.6 telnet .............................................................................................................................................. 38 5.2.7 hping3 ............................................................................................................................................ 39 5.2.8 tcpdump ......................................................................................................................................... 39 P LATTFORM - ÜBERGREIFENDE T OOLS .......................................................................................................................... 39 5.2.9 nmap (zenmap) .............................................................................................................................. 39 5.2.10 wireshark ....................................................................................................................................... 39 Notizen .......................................................................................................................................................... 41 KAPITEL 6 PORTSCANNING (NMAP) ..........................................................................................................43 6.1 W AS IST EIGENTLICH P ORTSCANNING ? ............................................................................................................ 43 6.2 D ER S ICHERHEITSSCANNER N MAP .................................................................................................................. 43 6.2.1 Nmap Grundlagen: Port-Zustände ................................................................................................. 44