PlantUML Server

@startuml
title DNS Resolve

skinparam SequenceMessageAlignment center

actor User as USR order 1
participant Client as CL order 2
participant "Local DNS Server" as LDNS order 3
participant "Root DNS Server" as RDNS order 4
participant "'.ch' DNS Server" as CH order 5
participant "'admin.ch' DNS Server" as ADMINCH order 6
participant "'www.admin.ch' Web Server" as WWW order 7

USR -> CL: Open Web Browser
USR -> CL: Type www.admin.ch in address bar

CL -> CL: Query **www.admin.ch** to hosts file
CL -[#red]>x CL: **www.admin.ch** is not in hosts file

CL -> LDNS: Query **www.admin.ch**
LDNS -[#red]>x LDNS: **www.admin.ch** is not on local DNS server

LDNS -> RDNS: Query **www.admin.ch**
RDNS -> RDNS: **www.admin.ch** is not on root DNS server
RDNS -> LDNS: **.ch** DNS server knows more, query that

LDNS -> CH: Query **www.admin.ch**
CH -[#red]>x CH: **www.admin.ch** is not on **.ch** DNS server
CH -> LDNS: **admin.ch** [ 162.23.130.190 ] DNS server knows more, query that

LDNS -> ADMINCH: Query **www.admin.ch**
ADMINCH -[#green]> ADMINCH: Query **www.admin.ch**
ADMINCH -> LDNS: Host **www** is 18.165.183.71

LDNS -> CL: Host **www.admin.ch** is 18.165.183.71

CL -> WWW: Query web page
WWW -> CL: Return web page

CL -> USR: Display web page
@enduml

PlantUML Server

Settings

Import Diagram

Export Diagram