That is normally something you do on the firewall, or an SD-WAN/SD-Branch device. This is not something straight-forward, and ISPs, firewalls, switches, routing design all may need to be taken into account. It may be something to work on with your networking partner. While the question may look pretty basic, especially for active-active loadbalancing over multiple ISP links it may be quite challenging to get that properly setup; and it's something that SD-WAN (or Aruba SD-Branch) is designed to do.
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Herman Robers
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If you have urgent issues, always contact your Aruba partner, distributor, or Aruba TAC Support. Check
https://www.arubanetworks.com/support-services/contact-support/ for how to contact Aruba TAC. Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
In case your problem is solved, please invest the time to post a follow-up with the information on how you solved it. Others can benefit from that.
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Original Message:
Sent: Jul 03, 2024 02:03 AM
From: Rford2798
Subject: How to route with two firewalls and each has their own ISP
I have been working on this for awhile, going back and forth with our Security person...
We have a network with a firewall on each "side" and each firewall has its own ISP. We want to set it up to send traffic out whichever one is currently up if either ISP goes down for whatever reason, but ideally, both would be active.
For Example:
ISP 1 <--> Firewall 1 <--> Switch A <--> Switch B <--> Switch C <--> Firewall 2 <--> ISP 2
I am trying to figure out how I can use routing to use either one with both connections being up. I'm using OSPF as my routing protocol and was thinking I could use a different metric maybe or some kind of static routes and then redistribute them. Has anyone done something similar to this or is there a better way to go about this? I thought maybe EIGRP instead of OSPF?