I have real Cisco routers and switches but most of the time I rather use virtual devices based on Dynamips. They are portable with my laptop, don’t consume additional electricity and provide me with and environment to test features anywhere I go with my laptop. I use it to test QoS, MPLS, IP routing (with OSPF, EIGRP, BGP), gatekeepers configurations, load-balancing, etc. It is just as having the real thing with you.
For example, during my last trip I found myself running 15 routers on my laptop, doing a BGP load balancing configuration validation for a service provider. (Well, I managed to do the job but my laptop’s battery was totally drained in little bit more than an hour). But the idea is that, it is a really flexible solution. (BTW, I run Linux so I don’t have the memory limitations that the Windows instances have.)
In my case, I have various network files for various topologies. This “Topology 1″ is the one the I most commonly use for testing of features, etc. Most of the examples and tips on this site will be tested using this topology as well.
When designing a “physical” virtual topology I try to make them flexible so that I can reuse them on different scenarios without the need to recreate them.
I use the following as my basic Cisco Virtual Lab Topology I
This topology, while simple, is very powerful. With it I can simulate a huge variety of topologies and arrangements. If you look closely you may find hope-and-spoke, star topologies, linear topologies, mixed topologies, etc.
This is the “topology1.net” file.
# # START OF FILE # autostart = False [localhost:7200] workingdir = /path/to/my/workingdir/topology1 [[3640]] image = /path/to/my/image/image_name-extracted.bin idlepc = ram = 128 rom = 4 iomem = 5 mmap = False #Force to run in real memory ghostios = True exec_area = 64 nvram = 128 [[ROUTER R1]] model = 3640 console = 2000 slot0 = NM-4E slot1 = NM-4T s1/0 = FR 1 s1/1 = R2 s1/1 s1/2 = R2 s1/2 s1/3 = R3 s1/3 e0/0 = SW 11 # Or E0/0 = NIO_linux_eth:eth0 e0/1 = SW 12 e0/2 = SW 13 e0/3 = SW 14 [[ROUTER R2]] model = 3640 console = 2001 slot0 = NM-4E slot1 = NM-4T s1/0 = FR 2 e0/0 = SW 21 e0/1 = SW 22 e0/2 = SW 23 e0/3 = SW 24 [[ROUTER R3]] model = 3640 console = 2002 slot0 = NM-4E slot1 = NM-4T s1/0 = FR 3 s1/1 = R4 s1/1 s1/2 = R4 s1/2 e0/0 = SW 31 e0/1 = SW 32 e0/2 = SW 33 e0/3 = SW 34 [[ROUTER R4]] model = 3640 console = 2003 slot0 = NM-4E slot1 = NM-4T s1/0 = FR 4 e0/0 = SW 41 e0/1 = SW 42 e0/2 = SW 43 e0/3 = SW 44 [[FRSW FR]] 3:304 = 4:403 2:204 = 4:402 2:203 = 3:302 1:104 = 4:401 1:103 = 3:301 1:102 = 2:201 [[ETHSW SW]] 11 = access 100 12 = access 200 13 = access 300 14 = access 400 21 = access 100 22 = access 200 23 = access 300 24 = access 400 31 = access 100 32 = access 200 33 = access 300 34 = access 400 41 = access 100 42 = access 200 43 = access 300 44 = access 400 # # END OF FILE #For more information visit:
Dynamips:
http://www.ipflow.utc.fr/index.php/Cisco_7200_Simulator
Dynagen:
http://dynagen.org
GUI for Dynagen and Dynamips. (Recommended for Windows users):
http://www.gns3.net
Dynamips Support Forum:
http://7200emu.hacki.at/index.php
I’ve tried your topology with Dynagen, It worked. How can I set VALNs on routers?
Please show us some routers configuration to understand the topology.(especially VLAN settings)
Thank you!
what do you mean by (?) in the addressing table?
Thanx.
Hi first to memmori: you don’t need to worry about any setting about vlan participating, just enable interfaces which are connected to same vlan for example you want that all routers will be in the same vlan just enable interface e0/0 on all routers and assign ip addresses. the switch in the topology is just like there are 4 virtual swicthes 100,200,300,400.
To author: i really like this blog it’s great