Multihomed IIS with two network cards

[lvilleda]

Recently, i have installed a system like this:

-Win2k, IIS, 2 network cards but just one card is configured to DMZ by behind a CISCO PIX (NATed to have a public IP address, this public ip is assigned by my ISP1 to my public domain name)

Everything was OK, but my ISP has failed 3 times this week.

Now, i need to install an alternate communication channel (ISP2) to support my site when my ISP1 is down.

Things that i'm thinking to do:

1-Get an alternate ISP to support my system when my ISP1 is down, connect an ISA Server (cheaper than my PIX) to support my second ISP.
Put my server into a DMZ to the second network card.
2-Get a domain name (www.example.com).
3-Get my own DNSs (ns1 and ns2) to support this domain.
4-Redirect my site to be supported by ns1 and ns2.
5-Add to my own DNS the public IP's, provided by ISP1 and ISP2.

The image is like this:

http://www.microsoft.com/technet/images/prodtechnol/isa/evaluate/images/isat12_BIG.gif

The difference is that i won't have an array of ISA in my alternate ISP.


Will it work?

Any suggestions.

[thirdfey]

I've heard that this should work if you setup all your outgoing and incoming listeners correctly but I think you would be better off asking this question on ISAserver.org where you will run into many people that specialize in ISA Server. It might even be covered in one of the tutorials on the site.

[imaeditedbysowulo]

That sounds like it would work but would make troubleshooting even more complicated should you run into problems in the future. I would suggest as an alternative getting a dependable ISP instead of the one you are using. Three times being down in one week is just not acceptable.

*edit* Just noticed you're in El Salvador...nevermind, you're probably stuck with that ISP?

[thirdfey]

I forgot to add that they do make routers now that give you the option to hook up two seperate broadband connections to do the work for you. Instead of you doing the research and configuring the ISA server to do it.

[gizmo1_1]

this public ip is assigned by my ISP1 to my public domain name)

Is your current ISP serving your DNS?


Put my server into a DMZ to the second network card.
Make sure the server has at least a software firewall for protection.
2-Get a domain name (www.example.com).
Is this a second domain name?
3-Get my own DNSs (ns1 and ns2) to support this domain.
Hosted by an outside DNS Service ?

Give em a few more details and I will try to assist you with a cost effective solution.

[lvilleda]

My domain (www.example.com) is hosted by ns1 and ns2 from ISP1

But i think to do this:

First that all, i have to re-delegate the domain www.example.com to be hosted by ns1.mydomain.com and ns1.mydomain.com.

ns1.mydomain.com with ISP1 (Record A to public Ip provided from ISP1)
ns2.mydomain.com with ISP2 (Record A to public Ip provided from ISP2)

Both DNS will be in DMZ's, firewalled, of course.

When a ISP1 fail, DNS1 will fail and ISP2 will be up, and DNS2 will be resolving my site.


I think.

[gizmo1_1]

This will work depending on the DNS Hosting Service. (With the problems that you are having with your link it woud futile to try to host dns yourself)

I know that your idea will work because I have used it my self in similar situations.

There will be inbound lag of course because some DNS servers cache IPs up to 72hours.

Many services offer fail-over suchas

http://www.website-backup.com/

http://www.tognet.org/result.php?Keywords=dns+hosting&host=www.tognet.org&relay=1&original=dns

Zoneedit.com (http://www.zoneedit.com)

These services often offer Heartbeat monitoring, and Zone failover protection.

As for the internal side, you can router plan that you described. and some creative manipulation. Or seperate syncronized servers.

[GHSTECH]

Have you tried this site?

www.isaserver.org

I have found answers there to most of my questions on ISA Server.