6 Replies Latest reply: Aug 24, 2019 10:35 AM by Martin RSS

    BGP lab





      I decided to do a BGP lab using GNS3 and the INE website provided the topology I'm attaching below.

      I'm buffled. Is this even possible to do on GNS3. A switch seems to be missing in the middle of the 4 routers.

      with a switch in the middle I could use dot1q trunks to connects the routers.

      also 2 ports on R1 have the same number.







        • 1. Re: BGP lab



          Some topologies reduce details and fo that reason it must be interpreted by the network administrator.  If you know about subinterfaces in the router and the possibly connection between them with a Switch, You can implement it as it really is


          This topology helps you identify the ip address and the interfaces where the devices are connected



          • 2. Re: BGP lab



            But I believe existing a error in the topology, because R1 can't have two subinterfaces with the same IP address. Then, my conclusion is that between R1 and R4 the subinterface could be:


            R1(f0/1.12) --- (f0/1.12)R4

            R1(f0/0.14) --- (f0/1.14)R4




            • 3. Re: BGP lab

              this is what i thought

              • 4. Re: BGP lab
                Juergen Ilse CCNA R&S

                The only switch included in GNS3 is (if i remembercorrectly) a non manageable switch with no vlan capabilities. But there are out ther older "IOU" images ("IOS on Unix", i saw such an image as 32 bit linux binary) and IOSv images, that can be run in qemu or VMWare. There are 2 different kids of IOSv images: L2 images (simulationg an IOS switch) and L3 images (simulation an IOS router). Same for the older "IOU" images, they also come in the 2 flavours L2 images and L3 images. -but you can also run virtuaized switches from other vendors. There is for example a cumulus linux as demo version availablle, that can be run in GNS3. That simulates a cumulus linux based switch. I think, there are other possibilities as well. But the necessary firmware files are not included in GNS3 (i think because of copyright reasons).

                • 5. Re: BGP lab

                  thanks Juergen


                  I have cisco swithces and routers which I will be connecting for the switch exam so for the time being what I have in mind is just to learn how to connect it all to GNS3 and manage it from there, if possible. any resources on how to do that will be muich appreciated.




                  • 6. Re: BGP lab

                    Yes, there should be gns3 video about connecting real gear to gns3 routers. the method is breakout switch, I did it sometime ago for my CCIE lab in Ubuntu. I use  5 switches but u can use 4. (not sure if the my lab shows real switches in my old post GNS3 testing)


                    - u do not need usb-to-Ethernet adapters or extra NICs. just use NIC that supports Vlan tagging (multiple vlans must pass thru NIC).

                    some Windows drivers do not support vlan tagging; other drivers will crash Windows. if your NIC in PC does not support Vlan tagging,  u can use Ubuntu as on Linux u can force tagging on NIC (more flexible then Windows drivers). this is what I did as my NIC driver kept crashing Windows


                    u can use following video or Rene's notes

                    Connect real switches to GNS3 using a Breakout Switch


                    some links to resources and options are mentioned in  GNS3 Testing IN Progress !