We set up a Azure site to site VPN connection to a Cisco ASA device, which in Azure shows 'connected' and some data out but no data in (0 B). The connection uses IPSec (IKEv2) which seems fine in Azure but shows no traffic on-prem. How is that possible?
Can I eliminate an issue with routing on Azure VNet? (we do have a custom route to direct traffic to VNet Gateway associated with both subnets: default + GatewaySubnet).
Pinging on-prem IP address from Azure VM in the VNet does increase data out, but still nothing is seen on-prem. May it be some NATing issue on-prem?
Any suggestion where to look? TIA.
Related
In our Azure tenant we have a Azure Firewall and a VPN connection with our on prem servers. I want to route all traffic through the azure firewall, whether it's incoming traffic from on prem to azure or outgoing traffic from azure to on prem.
For traffic inside azure I have created a routing table for each subnet and pointed to the firewall. Is this correct? And what do I have to configure for the on prem connection part. Further, how can I test it?
Thanks and best regards
To route traffic coming from the on-prem network, through the Azure Firewall, you also need to specify a route on the "GatewaySubnet".
This route table should contain the (Azure) subnets you want to reach from on-prem.
So if you for example have a subnet 10.5.5.0/24 in Azure, and you want to reach that from On-Prem.
Add a route table, with a route to 10.5.5.0/24, next hop type "Virtual Appliance" and Next Hop IP the private IP of your Azure Firewall.
Add this route table to the GatewaySubnet. (Some times you cannot assosiate from within the route table itself, but have to to through Virtual Network > Subnet and specify the route table there.
(And allow the traffic in the Azure Firewall.)
I deployed an openvpn virtual appliance and clients can reach peered networks, the VNET of the appliance itself, but not the network onpremise that is reachable via the virtual network gateway (routed VPN). When I use the P2S OpenVPN provided from Azure clients can reach onpremise network. What am I missing ?
I deployed an OpenVPN appliance because Azure OpenVPN lacks ccd support.
I solved the problem by adding the OpenVPN client IP range to the VNET address space. I then created a subnet with the same IP range. Obviously, you can't put any resource in this subnet. By then adding this subnet to the route, OpenVPN clients could traverse the gateway.
After my test on my windows client, I can directly access the on-premise network from the Azure VPN gateway based VNet or access the resources in the VPN based VNet from the on-premise network. You could follow these tutorials:
Configure a Point-to-Site connection to a VNet using native Azure certificate authentication: Azure portal
Set up OpenVPN® Protocol on Azure VPN Gateway.
Configure OpenVPN clients for Azure VPN Gateway
I have not deployed an OpenVPN virtual appliance, but I think it will be something like this: Point-to-Site (P2S) connection using OpenVPN infrastructure
According to this quick start, If you use a virtual VPN appliance, It is necessary to create a routing table on Azure so that traffic to your VPN subnet is directed back to your VPN instance and enable IP forwarding for this network interface. You could get more details about custom routes.
Feel free to let me know if I am misunderstanding you.
I'm trying to setup a VPN connection from a VLAN in Azure to on-premise. We have two different ISP's on-premise and I want to setup Azure with a VPN connecting to both so that if the primary ISP is down Azure will try to connect using the secondary.
The problem is that I can't add two gateways to a single VLAN, and the one gateway will not let me add two VPN connection with the same IP address range. I can understand that if I wanted both to be active, but I want one to be standby and only used if the first disconnects.
Is this even possible? Any pointers would be great?
I have been looking at https://learn.microsoft.com/en-us/azure/vpn-gateway/vpn-gateway-highlyavailable#a-name--activeactiveonpremamultiple-on-premises-vpn-devices but that only covers active-active setup which is not what I want.
I want both VNET resouces and on-premise resources to reach each other via the same IP addresses no matter if it's the primary or secondary VPN that's connected.
I know that Azure has fail over on it's side via a standby gateway, but I want fail over when on-premise is down, not Azure.
Update
I know that Azure has fail over on it's side via a standby gateway,
but I want fail over when on-premise is down, not Azure.
Unfortunately, there is not an auto solution for on-premise failover, you could manually perform, which is the same as If the on-premises gateway IP change need to update the same entry. You need to update the local network gateway (Including the On-premises gateway IP and private range ) on the Azure side and the ISP settings where VPN is connected on the on-premise side. Please expect some downtime, because IPSEC session of ISAKMP, PH1 and PH2 Will again take place.
Besides, If you have more than one ISP and need a redundant connection to the Azure. Azure now supports redundant Site to Site VPNs.
Support multiple tunnels between a VNet and an on-premises site with automatic failover based on BGP
You can establish multiple connections between your Azure VNet and
your on-premises VPN devices in the same location. This capability
provides multiple tunnels (paths) between the two networks in an
active-active configuration. If one of the tunnels is disconnected,
the corresponding routes will be withdrawn via BGP and the traffic
automatically shifts to the remaining tunnels.
The following diagram shows a simple example of this highly available setup:
NOTE
BGP is supported on Azure VpnGw1, VpnGw2, VpnGw3, Standard and HighPerformance VPN gateways. Basic SKU is NOT supported.
BGP is supported on Route-Based VPN gateways only.
We have an Azure WebJob running on an App Service connected to a vNET via Point-to-Site connection.
That same vNET is then connected to the on-premise network via a Site-to-Site VPN connection.
Routing is set up so to the Site-to-Site conn so that that the IP range of the Azure vNET (172.27.0.0/24) is sent from OnPrem > Azure. This can be tested by logging in to a VM inside of the vNET to query on premise resources - this works fine, and as expected.
If the same request (to a REST API) is sent from the WebJob, things do not work.
The IP range of the Point-to-Site (172.27.1.144/28) does not intersect with that of the vNET, so i am wondering if we need to also route this range "back across" the Site-to-Site connection also?
Another alternative is that a routing table within Azure needs to have a manual entry, somehow?
Any tips on how to troubleshoot / get this working would be much appreciated.
The IP range of the Point-to-Site (172.27.1.144/28) does not intersect
with that of the vNET, so i am wondering if we need to also route this
range "back across" the Site-to-Site connection also?
You need to do that, indeed. Not only that, you need to configure this network range (172.27.1.144/28) on your on-premises router too - so it recognises and accepts the traffic.
But in order to make the routing from the Point-to-Site (Azure app service) to the on-premise over the Site-to-Site VPN Connection, you will need to use a Virtual Appliance which is capable of forwarding the traffic.
For sake of simplicity and cost savings, you could just use Azure Hybrid Connections to connect Azure Web App / Web Job to on-premise Resource.
You can also refer to the documentation here, which lists the limitations of connecting App Service Plan to a Virtual Network, namely:
There are some things that VNET Integration does not support
including:
mounting a drive
AD integration
NetBios
private site access
Please note the last one - private site access - this is your on-premises.
I have a couple of queries about Azure VNet to On-Premises Site-to-Site networking -
As per Azure, Site-to-Site connection between On-Premises and Azure VNet should have a VPN tunnel. For this to happen there should be a VPN supported device at On-Prem and also a VPN Gateway at VNet. Is my understanding correct ?
Secondly, if a custom device capable of VPN functionality is deployed at On-Prem as well as a VM in Azure VNet, can they establish a connection between them without default Azure provided Site-to-Site VPN tunnel ? Is it possible to establish a network in Site-to-Site without VPN tunnel like with just igw's(Internet Gateways in AWS Cloud)?
What is the significance of next hop being "Internet" in azure route table ?
Yes. This device should also have a real external ip address, not behind the NAT.
Yes, you could use, say, Sophos to create VPN without using Azure's default VPN.
Internet. Represents the default Internet gateway provided by the Azure Infrastructure. (https://azure.microsoft.com/en-us/documentation/articles/virtual-networks-udr-overview/)