2 networ adapters, 2 gateways

Posted on 2013-06-02
Last Modified: 2013-06-07
Dear experts,

I have 2 servers connected to internet. Besides internet conectivity, there is another network adapter in each server. I need to set cross backup through that additional network adapters.


server-1 (internet connection)

server-2 (internet connection)

server-1 (cross backup connection)

server-2 (cross backup connection)

There is a cable directly connected to both "cross backup adapters", no switch.

My questions are:
1, is it supported scenario?
2, do I need to run route add command?
3, are there any disadvantages

Question by:Jaroslav Latal
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
LVL 15

Expert Comment

ID: 39214356
If anything works I would be amazed based on your description.

I would suggest that you go to the pfSense Firewall site and read through the documentation on fail over and redundancy support, 

LVL 10

Accepted Solution

bigbigpig earned 500 total points
ID: 39214389
That should work, just make sure you use a crossover cable, not a standard straight through cable, to connect them to each other.  You also don't need to define a gateway if the 2 NICs are connected directly to each other.
LVL 25

Expert Comment

by:Tony Giangreco
ID: 39214493
We have six servers, two ISP's and a Sonicwall TZ210 which handles all traffic from both web connections. I suggest setting this up with the firewall and not having Windows do it. We tried this before and could not keep it stable. From our experience, Windows is not well suited to handle this in a stable manner on a long term stable.
Simple, centralized multimedia control

Watch and learn to see how ATEN provided an easy and effective way for three jointly-owned pubs to control the 60 televisions located across their three venues utilizing the ATEN Control System, Modular Matrix Switch and HDBaseT extenders.


Author Comment

by:Jaroslav Latal
ID: 39218679

Sorry about late response, we have a little flood here in Prague.

TG-TIS: What kind of unstability do you mean? We do not want to spend extra money if not necesstary.

bigbigpig: Thanks! We do not have crossover cable and it works in our "lab". Maybe newer functionality of our NIC. Do you use this scenario somewhere? Some complications?

PhonebuffPosted: Amazed? Do you have any real experience with this? :)

LVL 15

Expert Comment

ID: 39218762
I guess,

    Redundant Firewalls, with redundant Switches with 9 servers with Dual NICS in a Colocation facility rack and zero down time in five years.

    Most NICs and the switch technology these days are auto sensing so no you don't need a cross over cable..

    But you need to do some reading on Load balancing and redundant links.   Again there is good information on the net at and other open source firewall products sites.

Author Closing Comment

by:Jaroslav Latal
ID: 39229953
I tried this and it works with no GW defined. The only problem is slower printing. I hope nothing else will appears.


Featured Post

Enroll in May's Course of the Month

May’s Course of the Month is now available! Experts Exchange’s Premium Members and Team Accounts have access to a complimentary course each month as part of their membership—an extra way to increase training and boost professional development.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
Internet monitoring software 5 57
Cannot Change Local DNS 9 94
DNS/WINS in a domain 10 93
How to connect/ping from virtual (VMware) system to host system also host network ? 2 109
Large and small networks have one same need, Service monitoring. Service monitoring consists of watch services of the several servers in the network. To monitor means that the administrator will receive an alert when a service is down or it's state …
Enterprise networks where VoIP phones have been deployed frequently use port configurations that allow both a computer and an IP phone to be plugged into the same switch port but use different VLANs. On Cisco equipment I'm referring to the "native V…
Here's a very brief overview of the methods PRTG Network Monitor ( offers for monitoring bandwidth, to help you decide which methods you´d like to investigate in more detail.  The methods are covered in more detail in o…
This video gives you a great overview about bandwidth monitoring with SNMP and WMI with our network monitoring solution PRTG Network Monitor ( If you're looking for how to monitor bandwidth using netflow or packet s…

751 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question