A Presentation about ZeroConf and Service Discovery.

1. Zero Configuration
Networking
BY MURILLO GRUBLER

2. Zero Configuration Networking
 Service Discovery
 Zeroconf, what is it?
 Tecnology of Discovery
 IPv4LL
 Multicast DNS
 DNS-SD
 Main Implementations
 References
2

3. Service Discovery
Service discovery aims to detect services on various devices on a
network of computers and allow them to use with minimal configuration.
Examples:
 Zero Configuration Networking
 UPnP
 SLP (Service Location Protocol)
3

4. Zeroconf, what is it?
Created in 1999 by the group IETF (Internet Engineering Task Force), the
Zero Configuration Networking (Zeroconf) is a methodology and a special
set of technologies that enable the configuration of a network and
discovery of services in a simple way that an average user will not notice.
 Distribute IP addresses (without a Dynamic Host Configuration Protocol
(DHCP) server)
 Provide name resolution (without a Domain Name System (DNS) server)
 Find and list services (without a directory service)
 Distribute multicast IP addresses, if necessary (without a multicast server)
4

5. DHCP (Dynamic Host Configuration Protocol)
5

6. DNS (Domain Name Server)
6

7. Tecnology of Discovery
 IPv4 Link-Local;
 Multicast DNS;
 DNS Service Discovery;
7

8. IPv4 Link-Local Address
 There is no central server
 Each unit is responsible for choosing address
 The IPv4LL uses ARP (Address Resolution Protocol) to find a free IP
 This choice is made randomly from an address comprised of
169.254.1.0 to 169.254.254.255
8

9. Multicast DNS
 There is no central server;
 The machine chooses its name;
 MDNS Responder;
 Queries to confirm a name and advertise services;
 Broadcast;
 MDNS uses the special multicast group 224.0.0.251;
9

10. DNS Service Discovery
 With the DNS-SD, the computer will automatically search for services
on the network;
 DNS-SD works well with the MDNS but also works with the classic DNS;
 Messages for service discovery are of the same format queries;
 The queries are of type SRV, PTR, A and TXT;
10

11. DNS Service Discovery - Types
 SRV: Contains name, service port, and host name;
 PTR: Is a pointer, stores the service type and service name;
 A: Stores the IP address of the service;
 TXT: It is used for additional service information;
11

12. Main implementations
 Apple Bonjour;
 Avahi
 Mono.Zeroconf
 J-Share
 ZCIP
 JmDNS
 pyZeroConf
12

13. Example – Mono.ZeroConfig
Main programn: Banshee
List with all definitions: http://www.dns-sd.org/ServiceTypes.html
 http: World Wide Web HTML-over-HTTP
 daap: Digital Audio Access Protocol (iTunes)
13

14. References
 Oliveira F. A. Estudo sobre Redes Ad-Hoc Móveis com Suporte à
Descoberta de Serviços. Espirito Santo: 2011
 Siddiqui F; Zeadally S.; Kacem T.; Fowler S. Zero Configuration
Networking: Implementation, performance, and security; Computers
& Electrical Engineering: September 2012, Pages 1129–1145
 Trabalho zero. Available in http://www.linux-
magazine.com.br/article/trabalho_zero. Access on April 19, 2014
 Zeroconf. Available at http://www.zeroconf.org Access on April 18,
2014
 Multicast DNS. Available at http://www.multicastdns.org Access on
April 19, 2014
14