Custom domain for Azure application gateway

It's not supported, you cannot setup a custom DNS Name, i have opened a ticket with microsoft support department.

You will have a DNS name like: 12-232-4-334-2-34-2343.cloudapp.net, you can use a CNAME for example, making www.web.com go to 12-232-4-334-2-34-2343.cloudapp.net .

PD: also, the public IP must be dynamic FYI.

Here are my lessons learned regarding the azure application gateway:

1.) Application gateway does _not_ support statically addressed public IPs
2.) Application gateway does _not_ support public IPs with a DNS name (e.g. somename.cloudapp.net)
3.) The application gateway’s DNS name _should_ be used to create a CNAME record which points to a friendly DNS (i.e. myawesomesite.com)
4.) The use of an A-record is _not_ recommended because the VIP may change on restart of the application gateway

Run this powershell script to get the gateway DNS:

Login-AzureRmAccount
Set-AzureRmContext -SubscriptionName '<Azure Subscription Name>'

$resourceGroup = 'myresourcegroup'
$pubIpName     = 'mypubip'

Get-AzureRmPublicIpAddress -ResourceGroupName $resourceGroup -Name $pubIpName

Look for something like this in what's returned from the script above:

DnsSettingsText: {
    "Fqdn": "00000000-1111-2222-3333-444444444444.cloudapp.net"
}

The fqdn is what you'll use to setup your CNAME.