> > Said that I haven’t played with GNS3, EVE-NG, VIRL,… recently so I don’t > know if any of these would allow me to create these massive “spreadsheets” > for programmatic generation of labs. >
GNS3 you can, they have a fairly well documented JSON based API that you can use to script up all the things, connections, and visual layout as well. I've only played with it on a rudimentary level, but it seems to work just fine. On Thu, Oct 17, 2019 at 8:14 AM <[email protected]> wrote: > I’ve been using network simulation well before GNS3 was around using > dynamips - and even when GNS3 came along it was still not good -since it > just couldn’t handle the scale (~40nodes) (not on my compute resources at > that time anyways). > > > > And similarly nowadays in the era of proper HW simulation through VMs > (though I miss the idle-pc), I really like virsh/libvirt along with OVS as > it allows me to programmatically generate the VM files (xmls, images, > etc..) and define the topology in OVS (talking hundreds of links) which > would be otherwise really tedious to draw by hand. > > Also spinning up a big virtual lab from scratch takes several hours (of > pure compute time) so it’s better to have some meshing in between the nodes > and just spin up arbitrary L1 topologies on demand rather than spinning up > the VMs every time one needs to load a different topology. > > Said that I haven’t played with GNS3, EVE-NG, VIRL,… recently so I don’t > know if any of these would allow me to create these massive “spreadsheets” > for programmatic generation of labs. > > > > Best approach is to have at least two virtual environments > > 1) closely resembling production environment -this is where designers and > Ops people can test day to day operational changes etc.. > > 2) environment where architects can test strategic/evolution changes to > the network infrastructure, new concepts and big migration/integration > projects, etc… > > > > What is it good for: > > Testing design concepts > > -this is one of the biggest advantages of virtual testing > > Physical labs as we all know cost a small fortune and you can simulate > just a small cross-sections of your overall topology at a time -but in > virtual lab depending on your computing resources and depending on what you > need to test you can either simulate very large sections or complete > network (at lower resolution) or smaller sections with very high resolution > or combination of both. > > This allows you to really see what happens to your traffic patterns and > assess the impact of your design changes from small to large scales. > > > > What is it not good for: > > A) Scale testing > > i.e. how many bgp/bfd/vrrp/etc.. sessions how many routes/VRFs/etc… - you > need the actual HW resources to carry out these tests > > B) Performance testing > > How much pps I can drive through NPU with these features > (QOS,filters,etc…) what are the failover times, (fast reroute, fabric > fail,RE fail, etc…) -again you need the actual HW that will be used in > production to measure these > > > > But as you can see A) and B) can easily be tested with a single DUT (or > some small topology around it) using actual HW plugged in a loop with > IXIA/Spirent testers. > > > > adam > > > > *From:* NANOG <[email protected]> *On Behalf Of *Ryland Kremeier > *Sent:* Wednesday, October 16, 2019 4:31 PM > *To:* <[email protected]> <[email protected]> > *Subject:* Viability of GNS3 network simulation for testing > features/configurations. > > > > Hello, > > > > I’m currently in the process of setting up a near identical network to our > own in GNS3 for testing purposes. Has anyone here tried this before to any > success? We need to buy the Cisco IOSv image to continue with the sim so I > figured I would inquire here first before diving in. > > > > All info is appreciated, > > -- > > Ryland Kremeier >
