DomainNameService

Domain Name Service (DNS)

mapping between IP-Adressen and names that can be remembered!

1. b. iem.at 193.170.191.181

• 1 addresse 1 name
• 1 addresse many names
  • virtual hosts (e.g. 193.170.191.183 {www.iem.at, sonenvir.at})
• many addresses 1 name
  • load balancing (z.b. google.at {193.170.141.249, 193.170.141.212, 193.170.141.234,...} )

mapping of additional data:

MX record (mail exchange)

mail-server for iem.at is mail.iem.at

TXT record ("free text field")

SPF (Sender policy framework)

"who (which server) is allowed to send emails on behalf of X?"

v=spf1 +mx +a +ip4:193.170.191.182 ~all

SRV (ZeroConf service)

"is there a server available, that allows me to ... print?"

_print._tcp 3600 IN SRV 10 0 389 printer.example.com.