sajitsasi / az-ip-fwd Goto Github PK

IP forwarding is enabled by

echo "1" > /proc/sys/net/ipv4/ip_forward

This does not survive a reboot. Which lead to some troubleshooting when it broke.

The steps I took to make it persistent.

Open for edit

sudo nano /etc/sysctl.conf

Uncomment following line (arrow down -> DEL the "#")

net.ipv4.ip_forward=1

Save

CTRL+O => Enter

Exit nano

CTRL+X

See file content

cat /etc/sysctl.conf

@sajitsasi I was directed to this script from MS document https://docs.microsoft.com/en-us/azure/data-factory/tutorial-managed-virtual-network-on-premise-sql-server. I copy/pasted the code to ubuntu terminal and ran the script but it's throwing error in below lines. Can you help and see why so??

Line 19: if [[ $# -eq 0 ]]; then

Line 85: if [[ ${DEST_HOST} =~ ^[0-9]+.[0-9]+.[0-9]+.[0-9]+$ ]]; then

Instead of powering through with success, please check if prerequirements host and iptables exists on the host where the script is ran.

Either offer to install requirements Y/n, or crash/exit the script.

Rules generated by this script are not persistent. Script and README.md says nothing about this.

Either mention it in the README.md, and point to options for persistence. Like iptables-persistent.
Or handle it in the script.

I managed to make it persistent like so:

Make iptables persistent

Export current IP tables to a file

sudo iptables-save > ~/rules.v4

Copy file to the location iptables-persistent will use on reboot

sudo /bin/cp -rf ~/rules.v4 /etc/iptables/rules.v4