We are in the email marketing industry and looking for IP GRE tunneling consulting.
We're looking for someone with experience in centos GRE tunneling between centos servers. We have one master server and 8 slave servers.
We want to use linux GRE tunneling (not route gre tunneling) to tunnel slave server's IP back to master servers. So that our mailing platform on the master server can use slave server's IP to send email.
Please notice that we want to do consulting. We've already have some commands to achieve it but it didn't work well.