Originally Posted by trisha26
what must I obtain to enable routing on my Linux network
Please elaborate your question.
Make one system as router to forward the packets to external network and set following parameter to 1 in /etc/sysctl.conf file of routing server
net.ipv4.ip_forward = 1
Also set appropriate IPtable rules on router server to secure your Linux machines from external network.
Here are couple of tutorials which will come to your help.
Setup Linux as router