As usual, notes is for myself and might be useful and also save time for beginners start using GNS3.
Ciso IOS images
It is not easy for beginners to find Cisco IOS images. I found this link with google search: Working Cisco IOS for GNS3. I hope it is still available when you read this note.
Juniper
Download working Juniper Junos for GNS3
Appliance Template
Location of appliance templates on Fedora
Appliance template files have '.gns3a' as their extension. Know where these templates' location in case you need to edit one of these templates. Example to find these template files on Linux.
[tuyen@g73jh ~]$ sudo find / -name *.gns3a 2>/dev/null [sudo] password for tuyen: /tmp/tmpkhl7qd30.builtin.gns3a /tmp/tmp51sg41c5.builtin.gns3a /tmp/tmph7igq3he.builtin.gns3a /tmp/tmp9luytesd.builtin.gns3a /usr/lib/python3.7/site-packages/gns3server/appliances/security-onion.gns3a /usr/lib/python3.7/site-packages/gns3server/appliances/fortisiem-super_worker.gns3a /usr/lib/python3.7/site-packages/gns3server/appliances/juniper-vqfx-pfe.gns3a /usr/lib/python3.7/site-packages/gns3server/appliances/arista-ceos.gns3a /usr/lib/python3.7/site-packages/gns3server/appliances/cisco-3725.gns3a /usr/lib/python3.7/site-packages/gns3server/appliances/bigswitch-bigcloud-fabric.gns3a ...
GNS3 VM
I also run GNS3 on Windows 10. When I upgraded GNS3 version 2.1.15 to 2.1.21, I got the following error:
Failed to connect to GNS3 VM (GNS3 VM): GNS3 version 2.1.21 is not the same as the GNS3 VM version 2.1.15. Please upgrade the GNS3 VM.
So, power on GNS3 VM (running on VMware Workstation) and upgrade that VM to 2.1.21 too.
GNS3 on Fedora Workstation 30
I have followed this article, step-by-step to install and run GNS3 successfully on Fedora Workstation 30: How to Install GNS3 on Fedora 29 / Fedora 28
Related tools/softwares
>>> eve-NG