=====Redhat Route=====

==== route-ethX ====

/etc/sysconfig/network-scripts/route-ethX



Various startup & control scripts in RHEL expect networking to be setup in a certain way. When it is, failures/stops/starts/restarts/reloads will work smoothly on the server. 

Here is the recommended method for setting up additional network routes;



  * Create a separate routing file for any additional routes, with the routes in the relevant files based on the Gateway they use.\\ 

  * The name of the file should be route-**NIC**, with **NIC** being the network interface name in question.

  * The file needs to have the three variables (ADDRESS, NETMASK & GATEWAY) numbered sequentially, starting from 0.

  *Subsequent static routes must be numbered sequentially, and must not skip any values. For example, ADDRESS0, ADDRESS1, ADDRESS2, and so on.



  [root@fworksapp1 network-scripts]# cat route-bond1 
  ADDRESS0=172.16.68.0
  NETMASK0=255.255.255.0  
  GATEWAY0=172.16.103.254
  
  ADDRESS1=10.13.5.80
  NETMASK1=255.255.255.255
  GATEWAY1=172.16.103.254



Here's a table showing common examples of translations between subnets, notations & netmasks;

^ Netmask ^ Notation ^ Hosts ^
| 255.255.0.0 | /16  | 65534 hosts |
| 255.255.255.0 | /24  | 254 hosts |
| 255.255.255.224 | /27  | 30 hosts |
| 255.255.255.240 | /28  | 14 hosts |
| 255.255.255.255 | /32 | 1 host |


document from Redhat [[https://access.redhat.com/site/documentation/en-US/Red_Hat_Enterprise_Linux/5/html/Deployment_Guide/s1-networkscripts-static-routes.html| here]]

There are resources on the internet that can aid in calculation of further Netmasks/Notations.\\ (ask Google to help you find your favourite)