Avatar of merker19
Flag for United States of America asked on

Two ISP's and Cisco 5510

Hi- I will be upgrading the ISP for my site and I was wondering what the best way to do that would be, especially in regards to our email server. I've done some research and it appears that I can connect two live ISP connections to my Cisco ASA 5510, but that I can only have one ISP connection live at any one time --so basically one is active and the other is the failover. So basically, I have:

ISP A - Old ISP, which will be retired in 8 months
ISP A Public IP
ISP B Public IP

I have the live Cisco ASA 5510 and a spare Cisco ASA 5505.

What's the best process for this?
Hardware FirewallsRoutersExchange

Avatar of undefined
Last Comment

8/22/2022 - Mon

Configure for the average dual ISP scenario

You'll need to make sure you have all outside ACL's and NAT's lined up, but for the most part it's a straight-forward process. Make sure you are consoled in when making the routing (track) changes as it can remove the default route completely if anything isn't right.

As for the email server, make sure your NAT and ACL's are set correctly. You'll need both reverse DNS records to be created, and your MX records can have priority set to prefer your primary ISP.
Sandeep Gupta

better to put each ISP in different VRF like VRFA and VRFB and create IPSec tunnels over those vrf.

since you want to make Acitve/passive then use tunnel delay/BW properties.

like VRF A primary link TunnelA primary tunnel--delay 1000
VRF B secondary link TunnelB secondary tunnel-delay 5000

My apologies. I didn't complete my request.

I've seen that I CAN do the active/failover configuration with tracking on the Cisco ASA 5510, but I would like to have a scenario where I can have both ISP's working at once with:

User Group A using ISP A
User Group B using ISP B

The email server is on the DMZ on ISP A. Would it be possible to make it accessible by ISP B as well? To aid in the migration of the MX record? Or is there a better way? Thanks.
Experts Exchange has (a) saved my job multiple times, (b) saved me hours, days, and even weeks of work, and often (c) makes me look like a superhero! This place is MAGIC!
Walt Forbes

Log in or sign up to see answer
Become an EE member today7-DAY FREE TRIAL
Members can start a 7-Day Free trial then enjoy unlimited access to the platform
Sign up - Free for 7 days
Learn why we charge membership fees
We get it - no one likes a content blocker. Take one extra minute and find out why we block content.
Not exactly the question you had in mind?
Sign up for an EE membership and get your own personalized solution. With an EE membership, you can ask unlimited troubleshooting, research, or opinion questions.
ask a question

Thanks. It gives me some things to think about.