Network Simulators

Cisco:
Packet Tracer

Multi:
GNS3

Other:
ns-3
http://en.wikipedia.org/wiki/Ns_%28simulator%29

Opnet
http://en.wikipedia.org/wiki/OPNET

NetSim
http://en.wikipedia.org/wiki/NetSim

Juniper Notes

Olive reloaded or how to emulate Juniper routers
http://blog.gns3.net/2009/10/olive-juniper/

Juniper product images library
https://www.juniper.net/us/en/company/press-center/images/image-library/

Juniper Product icons & Visio Stencils
https://www.juniper.net/us/en/products-services/icons-stencils/

Monitoring Juniper Products
http://www.juniper.net/techpubs/software/nog/nog-hardware/html/nog-hardwareTOC.html

Portable Libraries
http://www.juniper.net/techpubs/resources/index.html