Update virtual-network-optimize-network-bandwidth.md

Removing EOL distribution Red Hat 7 from guidance. Updating Ubuntu guidance since by default Azure Kernel is the default kernel and also adding generic note about modern kernels 4.19+ which should include significant changes for network optimization.

Author: mabicca

articles/virtual-network/virtual-network-optimize-network-bandwidth.md

@@ -51,35 +51,15 @@ RSS is always enabled by default in an Azure Linux VM. Linux kernels released si
 
 ### Ubuntu for new deployments
 
-The Ubuntu Azure kernel is the most optimized for network performance on Azure. To get the latest optimizations, first install the latest supported version of 18.04-LTS, as follows:
+The Ubuntu Azure kernel is the most optimized for network performance on Azure. Currently all Ubuntu images by Canonical come by default with the optimized Azure kernel installed.
 
-```json
-"Publisher": "Canonical",
-"Offer": "UbuntuServer",
-"Sku": "18.04-LTS",
-"Version": "latest"
-```
-
-After the creation is complete, enter the following commands to get the latest updates. These steps also work for VMs currently running the Ubuntu Azure kernel.
+You can simply use the command below to make sure you are using the Azure kernel which is identified by -azure at the end of the version.
 
 ```bash
-#run as root or preface with sudo
-sudo apt-get -y update
-sudo apt-get -y upgrade
-sudo apt-get -y dist-upgrade
-```
-
-If an existing Ubuntu deployment already has the Azure kernel but fails to update with errors, this optional command set might be helpful.
+uname -r
 
-```bash
-#optional steps might be helpful in existing deployments with the Azure kernel
-#run as root or preface with sudo
-sudo apt-get -f install
-sudo apt-get --fix-missing install
-sudo apt-get clean
-sudo apt-get -y update
-sudo apt-get -y upgrade
-sudo apt-get -y dist-upgrade
+#sample output on Azure kernel:
+6.8.0-1017-azure
 ```
 
 #### Ubuntu Azure kernel upgrade for existing VMs
@@ -104,28 +84,9 @@ sudo apt-get dist-upgrade -y
 sudo apt-get install "linux-azure"
 sudo reboot
 ```
+### Other distributions
 
-### Red Hat
-
-In order to get the optimizations, we recommend that you create a virtual machine with the latest supported version by specifying the following parameters:
-
-```json
-"Publisher": "RedHat"
-"Offer": "RHEL"
-"Sku": "7-RAW"
-"Version": "latest"
-```
-
-Both new and existing VMs can benefit from installing the latest LIS. The throughput optimization is in LIS, starting from 4.2. Enter the following commands to download and install LIS:
-
-```bash
-wget https://aka.ms/lis
-tar xvf lis
-cd LISISO
-sudo ./install.sh #or upgrade.sh if prior LIS was previously installed
-```
-
-Learn more about Linux Integration Services Version 4.3 for Hyper-V by viewing the [download page](https://www.microsoft.com/download/details.aspx?id=55106).
+Most modern distributions should have significant improvements with kernels newer than 4.19+, you can check the current kernel version and make sure you are running a newer kernel.
 
 ## Next steps