I am currently working on a project using Vsat technology (internet) to link 10 branch offices located in different remotes areas to the head office. on each of the site, I have a 2921 Cisco router, 2960 Cisco switch respectively. In addition to this, the client requested we install microwave radio in each of the site including the head office. and all the microwave radios should be on the same LAN so as all the remote sites can communicate as if they are on the same location. though the Vsat will still be a source of internet to all these locations. My question is what is the best way to configure this radio link? Should I directly connect a microwave radio to an interface on a Cisco switch and create a vlan on the switch for traffic for microwave link traffic? Please advice.

  • Just to clarify - the microwave will link the sites together? Do all sites have a line of sight to the head office?
    – Ron Trunk
    Commented Jul 26, 2015 at 21:33
  • yes the microwave radios link the sites together. Not all sites have a line of site to the head office. Its only the closest site that has a line of site to the head office while another site closer to the site that has a line of site to the head office has a line of site to it an so on.
    – kole
    Commented Jul 26, 2015 at 21:56
  • So you will daisy chain the sites? So each site will have two radios (upstream and downstream)?
    – Ron Trunk
    Commented Jul 26, 2015 at 22:30
  • yes each site has two radios accept the HQ. yes I will daisy chain the sites
    – kole
    Commented Jul 27, 2015 at 19:54
  • Did any answer help you? if so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you could provide and accept your own answer.
    – Ron Maupin
    Commented Aug 12, 2017 at 3:44

1 Answer 1


The new microwave links will terminate via Ethernet. Plug that into your switch. Each site requires a unique private subnet(s), if that is not already configured. Create a unique point to point subnet/VLAN per microwave link (/30 bit masked network). The 2921 should trunk .1q to the switch. Now the 2921's can route.

  • Under normal operation each site has its own ISP/Sat link however if that were to go down it is possible to re-route each site via microwave to the HQ/Neighboring site for Internet.

  • Also, realistically, the customer may want to enable a VPN WAN backup over the ISP/Sat links in case the microwave link fails, which
    complicates the config further, but this is the how it should be

Be sure and test each scenario at each site and pay attention to failover and failback times.

This is a great routing job. Hub and spoke, or ring? You can do it.

  • If I understand your explanation correctly, the microwave link terminates on a gig interface port on the 2921 Cisco router and the port will be configure as a trunk.1q to the switch. The subnet is going to be on a Vlan right? Note:gig0/0 of the router has already been configured as a WAN link from the Vsat to the gig1/1 port of the same switch. So gig1/2 port of the switch will the configure as trunk for the microwave link as a Vlan? Please there is one thing I want you to understand here. The client does not want the radio link to go on internet at all.
    – kole
    Commented Jul 27, 2015 at 20:12
  • You could plug the microwave links directly into the 2921 so that you do not need a trunk to the switch. The radio link is a point to point link, not an Internet link. Let me know if you need help. Commented Jul 28, 2015 at 17:04
  • Since the Vsat (internet) and the microwave links coming from the 2921 Cisco router will be terminating on the same Cisco 24ports switch, should I segment the ports by creating a Vlan for some ports say fa0/1 - 0/12 and dedicate them to microwave link while the remaining ports will be for Vsat (internet) link?
    – kole
    Commented Jul 28, 2015 at 19:48
  • The only port requiring access to the microwave is the router port, so no need to plug the microwave link into the switch. Commented Jul 28, 2015 at 21:18
  • Thanks for your insight. Please i want to know if Router-on-a-Stick can work for this scenerio; On 2921 Series Cisco Router, i have int gig0/0 as WAN interface providing Internet access to the network, int gig0/1 as PTP radio link for the LAN only (no internet access allowed), int gig0/2 to be configure as router-on-a-stick for two different Vlan. One for each of the WAN and PTP radio. And on the Layer2 Swich connected to the router, we will have say...int 0/1 - 12 as internet Vlan while int 13 - 24 aPTP radio Vlan.
    – kole
    Commented Aug 15, 2015 at 10:27

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.