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How To: Add another Network Interface 'eth1' to AWS EC2 VM?

How To: Add another Network Interface 'eth1' to AWS EC2 VM?

Release Classification Level DB Platform Categories
3.6+ How To ALL Performance Tuning


  • How to Add another Network Interface (eth1,eth2 etc) in addition to existing out of the box eth0?
  • Simply adding it from AWS Console does not automatically reflect it in CentOS
  • Furthermore, trying to 'ifup' the new interface could result in VM hang requiring complete reboot.
  • Follow below steps to ADD another Network Interface to EC2 instance running ScaleArc on CentOS -

step-1 -  Create a New Network Interface within the same VPC


step-2 -  Navigate to your EC2 Instance to Add this new Network Interface

If the new Interface is not found in below step, it was probably created in a different VPC and needs to be checked.


step-3 -  Login to SSH and confirm if this Network Interface reflects in CentOS


step-4 -  Force your default gateway to be eth0

Edit /etc/sysconfig/network and add entry as below -

Note:  Failing to do above step will result in the new interface taking over default gateway of the main routing table which was earlier set to the original interface resulting in strange behavior such as VM hang.

 step-5 -  Configure the Interface you have added

In /etc/sysconfig/network-scripts, create an ifcfg-ethX for new interface.

For instance, This can be achieved by copying existing ifcfg-eth0 to create ifcfg-eth1


step-6 -  Bring up the new interface and verify
ifup eth1



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