Hlzatok 5 Lengyel Zsolt Protocollok DNS FTP NTP

Hálózatok 5. Lengyel Zsolt Protocollok: DNS, FTP, NTP, RDP, Telnet, SSH, Kerberos Email

Client-Server Vs Peer-to-Peer Web, Mail, FTP, SSH, …. Bittorrent Bitcoin

7. Application ICMP 6. Presentation 5. Session 4. Transport 4. Application Internet Control Message Protocol 3. Transport 2. Internet 1. Network Interface (Link) 3. Network pl. : Ping 2. Data Link 1. Physical icmp Checksum Type

7. Application 6. Presentation 5. Session 4. Transport IGMP 4. Application 3. Transport Internet Group Management Protocol 2. Internet 1. Network Interface (Link) 3. Network 2. Data Link 1. Physical 224. X. X. X Source Address Group Address Checksum Type

7. Application DHCP 6. Presentation 5. Session 4. Transport Dynamic Host Configuration Protocol 3. Network 2. Data Link 1. Physical 4. Application 3. Transport 2. Internet 1. Network Interface (Link) To: Client DHCPAcknowledge Offer DHCP Server to: ff: ff: ff To: Server DHCPDiscover Request DHCP Client DHCP hiba gyanú: 169. 254. 1. 0 -169. 254. 255 Link Local IP APIPA

7. Application DHCP 6. Presentation 5. Session 4. Transport Dynamic Host Configuration Protocol 3. Network 4. Application 3. Transport 2. Internet 1. Network Interface (Link) 2. Data Link 1. Physical ipconfig /release bootp. option. type == 53 ipconfig /renew sudo dhclient -r; sudo dhclient Server Configuration: Range/Pool. : pl 192. 168. 1. 10 - 192. 168. 1. 50 Lease time: pl. : 24 hours

7. Application 6. Presentation 5. Session 4. Transport DHCP Dynamic Host Configuration Protocol 3. Network 2. Data Link 1. Physical DHCP Server DHCP IP: 192. 168. 11. 5 192. 168. 11. 2 Static IP: 192. 168. 11. 2 Exclude: 192. 168. 11. 2 4. Application 3. Transport 2. Internet 1. Network Interface (Link)

MAC cím felderítés $ sudo nmap -R 192. 168. 95. 90 | grep MAC Address: E 8: 94: F 6: 12: 61: 22 (Tp-link Technologies)

VPN (Virtual Private Network) 12. 26. 93. 22 192. 168. 1. 3 84. 236. 63. 22 192. 168. 10. 1 VPN server 192. 168. 1. 1 192. 168. 10. 4 10. 8. 0. 1 192. 168. 1. 2 10. 8. 0. 2 192. 168. 10. 5 192. 168. 10. 3 10. 8. 0. 2 84. 236. 63. 22 12. 26. 93. 22 DST IP SRC IP 10. 8. 0. 1 10. 8. 0. 2 DST IP SRC IP Data

VPN (Virtual Private Network) TCP UDP IPsec PPTP

Internet Protokollok File transfer Web FTP, SCP HTTP, HTTPS Email Remote access Telnet, SSH, Remote desktop connection Fogadás: POP 3, IMAP Küldés: SMTP Name resolution DNS Net. BIOS-NS m. DNS

DNS Domain Name System FQDN = Fully Qualified Domain Name www. google. com hostname Top Level Domain name. com, . eu, . gov, . org … secondary domain abc. def. ghi. google. com

DNS Hierarchia Domain Name System … root server TLD. com server . hu server . org server … index. hu server www. index. hu server origo. hu server …

DNS cache google DNS: 8. 8 google DNS: 4. 4 . com - port: 53 UDP! 13. 24. 54. 89 . root server wired. com 45. 85. 4. 3 Root hints . com server www. wired. com 87. 42. 24. 1 hosts wired. com server www. wired. com 87. 42. 24. 1

Egy domain lekérdezése a helyi default dns szervertől host -a index. hu gy domain lekérdezése a google dns szerverr host -a index. hu 8. 8

Mik a root szerverek? host -t NS. Mennyi van ? host -t NS. | wc -l Mik a. hu szerverek? host -t NS hu info a. hu zónárol: (egy konkrét root szervertől kérdezve) host -a hu a. root-servers. net.

SOA Record host -t SOA hu host -t SOA index. hu http: //www. zytrax. com/books/dns/ch 8/soa. html

az index. hu lekérdezése egy választott. hu dns szerverről host -a index. hu 194. 0. 25. 11

DNS Server Konfigurálása DNS Query: oktatas. itstudy. hu ITStudy. hu zóna prompt. hu zóna

DNS rekordok típusai A Rekord NS rekord CNAME SOA rekord TXT rekord MX rekord …

Hosts file Windows: C: Windowssystem 32driversetchosts Linux/OSX: /etc/hosts Windows naming nbtstat -c, -s

DNS Hibakeresés dig whois ping

Rouge DNS server Fake Web Server 42: b 8: a 2: 5 c: 32: 54 192. 168. 1. 1 m Dn o c. k que s re c o o eb fa w. 192. 168. 1. 15 w st /w / : p htt ARP Poisoning Fake DNS Server DNS request ip: 192. 168. 1. 10/24 dns: 192. 168. 1. 1 facebook. com: 192. 168. 1. 15 192. 168. 1. 1 12: 4 b: 32: 5 c: 12: 64

Dynamic DNS Dyn. DNS, DDNS http: //no-ip. com/ http: //dyn. com/dns/

email küldés: SMTP (25, TCP) Email SSL SMTP (587, 465 TCP) email fogadás: POP 3 (110, TCP) IMAP (143, TCP) SSL IMAP (993, 995 TCP) pista@gmail. com laci@freemail. hu

FTP data: 20, TCP FTP control: 21, TCP Client: Total Commander

Remote Desktop VNC: nem titkosított Team. Viewer Windows Remote Desktop Apple Remote Desktop

Telnet 23 TCP

SSH 22 TCP Secure Shell SSH thunnel SSH connection pl. : VNC

NTP Network Time Protocol Port: 123

Kerberos Authentication Server Windows Domain Controller Hash(Username, password) TGT Token Ticket Granting Service

#learnabout https: //en. wikipedia. org/wiki/File_Transfer_Protocol https: //en. wikipedia. org/wiki/Remote_desktop_software https: //en. wikipedia. org/wiki/Telnet https: //en. wikipedia. org/wiki/Secure_Shell https: //en. wikipedia. org/wiki/Caesar_cipher https: //en. wikipedia. org/wiki/Network_Time_Protocol https: //en. wikipedia. org/wiki/Cryptographic_hash_function https: //en. wikipedia. org/wiki/Kerberos_(protocol)