We have a site that currently has a satellite connection used by users, and a 3G connection used for a specific application. Connections are from different providers. Every connection has it's own router, switch and connections.

Is there a way, to move all users and servers to one switch and connect the two routers on that same switch to provide redundancy in case of one of them fails? E.g. if Satellite connectivity fails then everything will go via 3G and vice versa.

Thank you

  • 1
    Yes. (assuming you want to know how: HSRP/VRRP)
    – Ricky
    Commented Sep 10, 2015 at 6:34
  • 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 17:44

3 Answers 3


there are two solution first one will be the automatic and profissional solution and need to be done from the side of your routers and the other one i consider it as a way out

first one

if both USERS and Application servers and router interfaces from the lan side run same IP range so simple you just need to configure FHRP on both router and map all your devices to single GW .

  1. if you are using Cisco routers you can configure HSRP on both of them and make your devices GW the virtual IP of this HSRP
  2. if you are using non cisco routers you can configure VRRP on both of your routers and also make your devices GW VRRP virtual IP

second one

if your devices and router interfaces from the lan side run same IP range , may you login to each device and configure primary and seconry GW

  1. from start login to CMD as administrator then type

route add X.X.X.X mask Y.Y.Y.Y Z1.Z1.Z1.Z1 metric 10
route add X.X.X.X mask Y.Y.Y.Y Z2.Z2.Z2.Z2 metric 20
wher Xs are your lan ip range and Ys are the mask and Z1s are the primary GW and Z2s are the secondry one

  1. from the interface card login to the advanced setting then configure other GW with metric 20
  • Thank you for your feedback. Maybe I wasn't clear on what we are trying to do. We have two connection: 3G and Satellie. They exsit on same site but they are different connection. Different subnet range, different gateways etc. We want to keep it this way. Users with satellite and application with 3G. What we are trying to determine, is, if it's possible if one of these connections fail, can we in some way, dynamically roll over to the other connection. I'm sure there's a way like slas or something...
    – Babis
    Commented Sep 10, 2015 at 23:23
  • so you need users to be assigned [Rang_1 (i.e. 10.10.10.X/24)&GW_1] and in case of fail need to get [Range_2 (i.e. 20.20.20.X/24)&GW_2] OR you main users assigned same rang and different GWs
    – Gadeliow
    Commented Sep 11, 2015 at 1:25
  • Thanks for the info. I think I have enough to go on and test if required.
    – Babis
    Commented Sep 14, 2015 at 0:59

You actually have two issues :

  • Determining that the link is down
  • Using that information to modify your routing.

If you have a Cisco router behind the two connections, you would use IP SLA to track a remote device through each connection (typically by pinging it regularly), and then configure HSRP such that the HSRP priority on the main router is changed if ever its link goes down. Traffic will automatically move back to the main link once it's back up. See http://ciscodreamer.blogspot.fr/2009/09/ip-sla-with-hsrp.html for an example

The trick, especially on an Internet connection, is finding something that you can ping which will give you a reliable indication of whether your link is down or not, or else you will get spurious failovers.


Well, I am anti-Cisco solution Designer. We also have this situation around a year ago. We were using satellite backhaul for voice and data. Else, we were also connected redundant to a local operator via 3G connection. All we did is that we use a simple E1 to Ethernet convertor (Chinese converter). this converter has a DTE V.35 port for satellite and to transport this data we connect one port with VOIP gateway. As gateway was connected to data and Voice. Then for 3G connection we used the WAN port of the VOIP GW to a simple layer 2 swtich with activating the port preference. 3G and satellite were on 1+1 HSB. Then for that 3G connection we used a simple router with a SIM port on at WAN.Then we created a VPN from that remote site to the HUB site. You can use VPN of the router and get it connected to the HUB site. It is much more cheaper solution than Cisco. Its all about you skill and thinking. EVery item we used was a chinese made......

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