If you want to avoid having a single gateway server - thus risking a single point failure -, 

you can activate the gateway portal and load balancing on a second server - to provide a failover to your farm -.


All you have to do is replicate your load balancing configuration on your second server.

 

Once it's done, you may either provide: 

- the alternate URL to your users,

- and/or generate a new connection client that points to the new gateway.