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Site-to-site VPN
Meraki Auto VPN technology is a unique solution that allows site-to-site VPN tunnel creation with a single mouse click. When enabled through the dashboard, each participating MX and Z Series appliancesautomatically does the following:
- Advertises its local subnets that are participating in the VPN.
- Advertises its WAN IP addresses on Internet 1 and Internet 2 ports.
- Downloads the global VPN route table from the dashboard (automatically generated by the dashboard, based on each MX's advertised WAN IP/local subnet in the VPN network).
- Downloads the preshared key for establishing the VPN tunnel and traffic encryption.
The net result is an automatic mesh site-to-site VPN solution that is configured with a single click.
Setting up site-to-site VPN
Site-to-site VPN settings are accessible through the Security & SD-WAN> Configure > Site-to-site VPN page.
Type
There are three options for configuring the MX-Z's role in the Auto VPN topology:
- Off: The MX-Z device will not participate in site-to-site VPN.
- Hub (Mesh): The MX-Z device will establish VPN tunnels to all remote Meraki VPN peers that are also configured in Hub (Mesh) mode. The device will also establish VPN tunnels to other MX-Z appliances in hub-and-spoke mode, where the other MX-Z device configured as a hub.
- Spoke: This MX-Z device (spoke) will establish direct tunnels only to the specified remote MX-Z devices (hubs). Other spokes will be reachable via their respective hubs unless blocked by site-to-site firewall rules.
Hub Type
Exit Hubs
This option is only availableif the MX-Z deviceis configured as aHub.This option lets you designate the remote MX-Z device that is to receive all network traffic from the local MX-Z device. This creates a fulltunnel configuration where all traffic destined for a default route is sent to the specified MX.
Security features over full-tunnel VPN
In a full tunnel topology, all security and content filtering must be performed on the full tunnel client. The Exit hubwill not apply contentfiltering, Intrusion Prevention System (IPS) blocking, or malwarescanning to traffic coming in over the VPN. However, Intrusion Detection System (IDS) scanning will be performed for this traffic.
Spoke Type
Hubs
When an appliance is configured as aspoke, multiple VPN hubs can be configured for that appliance. In this configuration, the spokeMX-Z device will send all site-to-site traffic to its configured VPN hubs.
Default Route
When configuring hubs for aspoke, there is an option to select a hub asa Default route. If this option is selected, then that hub will be configured as a default route for the spoke (0.0.0.0/0). Any traffic that is not sent to a configured VPN peer network, a static route or local network will be sent to the default route. This routing will apply to any traffic originating from subnets set to, "In VPN" or that have VPN mode "Enabled." Subnetsthat have VPN mode "Disabled" will not adhere to the VPN routing tables. Multiple hubs can be selected as default routes. Hubs marked as default routestake priority in descending order (first priority at the top).
Configuring Multiple VPN Hubs
To add additional hubs, click the Add a hubbutton just below the existing hub that is selected. Only appliances in Mesh VPN mode can be hubs, so the number of Mesh VPN appliances in your dashboard organization represents the maximum number of hubs that can be configured for any given appliance.
The order in which hubs are configured on this page is the hub priority. Hub priority is used to determine which hub to use if more than one VPN hub is advertising the same subnet. The uppermost hub that meets the following criteria will be used to reach that subnet.
A) Advertisesthe subnet
B) Currently reachable via VPN
Hubs can be deleted by clicking on the grey Xto the right of the relevant hub under the Actionscolumn. The hub priority list can be reordered by clicking and dragging the grey four-point arrow icon to the right of any hub in the list to move that hub up or down.
Tunneling
There are two tunneling modes available for MX-Z devicesconfigured as a Spoke:
- Split tunnel (no default route): Send only site-to-site traffic, meaning that if a subnet is at a remote site, the traffic destined for that subnet is sent over the VPN. However, if traffic is destined for a network that is not in the VPN mesh (for example, traffic going to a public web service such as www.google.com), the traffic is not sent over the VPN.Instead, this trafficis routed using another available route, most commonly being sent directly to the Internet from the local MX-Z device. Split tunneling allows for the configuration of multiple hubs.
- Full tunnel (default route): The configured Exit hub(s)advertisea default route over Auto VPN to the spoke MX-Z device. Traffic destined for subnetsthat are not reachable through other routes will be sent over VPN to the Exit hub(s). Exit hubs' default routeswill be prioritized in descending order.
Concentrator priority
The concentrator priority determines how appliances in Hub (Mesh)mode will reach subnets that are advertised from more than one MerakiVPN peer. Similarly to hub priorities, the uppermost concentrator in the list that meets the following criteriawill be used for such a subnet.
A)Advertisesthe subnet
B) Currently reachable via VPN
It is important to note that concentrator priorities are used only by appliances in Meshmode. An appliance in hub-and-spoke mode will ignore the concentrator priorities and will use its hub priorities instead.
NAT Traversal
If the MX-Z deviceis behind a firewall or other Network Address Translation (NAT) device, there are two options for establishing the VPN tunnel:
- Automatic: In the vast majority of cases, the MX-Z devicecan automatically establish site-to-site VPN connectivity to remote Meraki VPNpeers even through a firewall or NAT device using a technique known as "UDP hole punching". This is the recommended (and default) option.
- Manual: Port forwarding: If the Automatic option does not work, you can use this option. When Manual: Port forwarding is enabled, MerakiVPN peers contact the MX-Z deviceusing the specified public IP address and UDP port number. You will need to configure the upstream firewall to forward all incoming traffic on that UDP port to the IP address of the MX-Z device.
Make sure the port number you have chosen is not already used by another service. For example, do not use port 500 or 4500 as these are used for Client VPN and 3rd party VPN peer communication.
Local Networks
If you have multiple LAN subnets, you have the option to specify which VLANs and static routes participate in the VPN.
The same subnet can only be advertised from more than one appliance if all appliances advertising that subnet are in Passthrough or VPN Concentrator mode. All subnets advertised from an appliance in Routed mode must be unique within the Auto VPN topology.
Subnets to which the MX-Z device has Static LAN routes can also be advertised over the VPN. If you choose to advertise a statically routed subnet over the VPN, ensure that the gateway device for each subnet is configured to route traffic for remote VPN subnets to the MX-Z device, in order to keep your routing symmetrical.
In full tunnelconfigurations when specifying a prefix to be part of a VPN, everything covered by that prefix will be allowed in the VPN. Therefore, subnets that overlap will causetraffic in amore specific subnet to be sent through the VPN, even if it is not configured to be included in the VPN. For example, if 10.0.0.0/16 is configured to be included in the VPN but 10.0.1.0/24 is not, traffic sourced from 10.0.1.50 will still be sent over the VPN.
VPN Subnet Translation
This feature is not enabled by default, please contact Meraki support to enable it.
Moreover, this feature is only supported for Auto VPN and is not intended to work with non-Meraki VPN peers.
In large distributed networks, multiple networks may have identical subnet scopes (for example,overlapping subnets). Site-to-site VPN communication requires each site to have distinct and non-overlapping local subnets. In the event that multiple locations have the same local subnet, enable VPN subnet translation to translate the local subnet to a new subnet with the same number of addresses. For more information, refer to theUsing Site-to-site VPN Translation article.
Subnet Translation Example
- Branch 1 local subnet: 192.168.31.0/24
- Branch 2 local subnet: 192.168.31.0/24 (identical!)
- Branch 1 translated subnet: 10.0.1.0/24
- Branch 2 translated subnet: 10.0.2.0/24
In the example above, even though both networks have identical local subnets, they can communicateover the VPN using their translated VPN subnet. Branch 1 is accessible as 10.0.1.0/24 and Branch 2 is accessible as 10.0.2.0/24 over the VPN tunnel.
Open Shortest Path First (OSPF) RouteAdvertisem*nt
Note: As part of MX 18.1 firmware updates we are introducing a new Routing page, more details found in the"OSPF Configuration"section of the article.
While the MX Security Appliance does not currently support full OSPF routing, OSPF can be used to advertise remote VPN subnets to a core switch or other routing device, avoiding the need to create static routes to those subnets. OSPF advertisem*nt is supported in VPN Concentrator mode or in Routed mode on MX 13.4+ firmware with VLANs disabled.
Advertise remote routes: If this is set to Enabled, OSPF will be used to advertise remote VPN subnets as reachable via this MX.
Router ID: The OSPF Router ID that this MX will use to identify itself to neighbors.
Area ID: The OSPF Area ID that this MX will use when sending route advertisem*nts.
Cost: The route cost attached to all OSPF routes advertised from this MX.
Hello timer: How frequently the MXwill send OSPF Hello packets. This should be the same across all devices in your OSPF topology.
Dead timer: How long the MX will wait to see Hello packets from a particular OSPF neighbor before considering that neighbor inactive.
MD5 Authentication: If this is enabled, MD5 hashing will be used to authenticate potential OSPF neighbors. This ensures that no unauthorized devices are injecting OSPF routes into the network.
Authentication Key: The Message Digest Algorithm 5 (MD5) key number and passphrase. Both of these values must match between any devices that you wish to form an OSPF adjacency.
WAN appliances in Routed mode only support OSPF when using the "Single LAN" LAN setting. This can be set onAddressing & VLANspage.
Non-Meraki VPN Peers
You can create Site-to-site VPN tunnels between a Security Appliance or a Teleworker Gatewayand a Non-Meraki VPN endpoint device under the Non-Meraki VPN peers section on theSecurity & SD-WAN > Configure > Site-to-site VPN page. Simply click Add a peerand enter the following information:
- A name for the remote device or VPN tunnel.
- What Internet Key Exchange (IKE) version to use (IKEv1 or IKEv2)*
- The public IP address of the remote device.
- Local ID of this MX. This is an optional configuration and is what the remote peer will receive as the remote ID of thisMX.
- If left blank (default) it is the uplink IP of the MX, not the public IP. Some peers may expect this to match the public IP of the MX,a User FQDN (for example,user@domain.com), or FQDN(for example,www.example.com) based on their configuration.
- The Remote ID of the remote peer. This is an optional configuration and can be configured to the remote peer’s User FQDN,FQDN, or IPv4 address as needed.
- Which of these values you use is dependent upon your remote device. Please consult its documentation to learn what values it is capable of specifying as its remote ID, and how to configure them (for example,Determining an ID Method for ISAKMP Peers for ASA firewalls).
- The subnets behind the third-party device that you wish to connect to over the VPN. 0.0.0.0/0 can also be specified to define a default route to this peer.
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Note that if an MX-Z device is configured with a default route (0.0.0.0/0) to a non-MerakiVPN peer, traffic will not fail over to the WAN, even if the connection goes down.
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- The IPsec policy to use.
- The preshared secret key (PSK).
- Availability settings to determine which appliances in your dashboard organization will connect to the peer.
Minimum Firmware Requirements:
- IKEv2 requires firmware version 15.12 or greater.
- IPv6 peering requires firmware version 18.2or greater.
When setting up Non-Meraki VPN connections between two MXs in different organizations, make sure to populate the Remote ID field of the Non-Meraki VPN peer with the private IP address of the remote MX if all of the following conditions are met:
- The MXs are running firmware version MX 15 or higher.
- They do not use a User FQDN.
- They are connectedbehind an upstream NAT device.
Non-MerakiVPN peers cannot useMX/Z appliances as an "exit hub" as they donot interpret a default route(0.0.0.0/0) as a valid traffic selector.
Making changes to Non-Meraki VPN settings under Security & SD-WAN > Configure > Site-to-site VPN, might result in existing Non-Meraki VPN tunnels bouncing. We recommend that you make changes during a maintenance window to minimize the impact of Non-Meraki VPN tunnels bouncing.
Non-Meraki VPN Peering with FQDN
This feature enables theuse of FQDN instead of an IP address while configuring a Non-Meraki VPN peer. Using IP addresses can be tedious because with a dynamic IP address, a customer has to manually modify the Non-Meraki VPN settings on the Site-to-Site VPN page when there is an IP address change. With FQDN configuration, the hostname of the remote peer would automatically get resolved each time a connection is initiated.
“FQDN” differs from “User FQDN.”The MX resolves the FQDN to an IP address of the remote peer, whereas, “User FQDN” is used in conjunction with the IP address of the remote peer. “FQDN” identifies the remote peer and is configured in the “Public IP/Hostname” field.“User FQDN” identifies the local peer and is configured in the “Local ID” field.
Supported Products:
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MX running firmware 18.1 or higher
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RequiresIKEv2
Configuration
The FQDN of the Non-Meraki VPN peer can be configured in the Public IP/Hostname field when IKEv2 is the selected IKE version.
The default behavior of the MX is to set remote_id to FQDN if it is not explicitly added in the dashboard Non-Meraki VPN peerssettings. Please note, the remote id on one peer needs to match the local id on the other peer for the tunnel to be established.
Ifthe configured FQDN fails to resolve,an event will be reported in Network-wide > Monitor > Event log on dashboard
NOTEFor IKEv2
Merakiappliances build IPsec tunnels by sending out a request with a single traffic selector payload that contains all of the expected local and remote subnets. Certain vendors may not support allowing more than one local and remote selector in a given IPsec tunnel.For such cases, please use IKEv1 instead.
An MX-Z devicewill not try to form a VPN tunnel to a non-Meraki peer if it does not have any local networks advertised.
IPsec Policies
There are three preset IPsec policies available.
- Default: Uses the Meraki default IPsec settings for connection to a non-Meraki device
- AWS: Uses default settings for connecting to an AmazonVirtual Private Cloud(VPC)
- Azure: Uses default settings for connecting to a Microsoft Azure instance
If none of these presets are appropriate, the Custom option allows you to manually configure the IPsec policy parameters. These parameters are divided into Phase 1 and Phase 2.
Phase 1
- Encryption: Select between AES-128, AES-192, AES-256, and 3DES encryption
- Authentication: Select MD5, SHA1or SHA256* authentication
- Diffie-Hellman group: Select between Diffie-Hellman (DH) groups 1, 2,5 or 14*
- Lifetime (seconds): Enter the phase 1 lifetime in seconds
* These settings requirefirmware version 15.12 or greater
Phase 2
- Encryption: Select between AES-128, AES-192, AES-256, and 3DES encryption (multiple options can be selected)
- Authentication: Select between MD5, SHA1 and SHA256 authentication (both options can be selected)
- PFS group: Select the Off option to disable Perfect Forward Secrecy (PFS). Select group 1, 2,5 or 14 to enable PFS using that Diffie-Hellman group.
- Lifetime (seconds): Enter the phase 2 lifetime in seconds
On May 8th 2018, changes were introduced to deprecate DES for encryption. Refer to theDeprecation of DES Encryption Algorithmarticle for more information.
NOTE: Please ensure the phase 2 lifetimes are equal on both ends of the tunnel whenever possible. While MX's can sometimes honor a shorter phase 2 lifetime if they're acting in response to build a tunnel, they cannot while serving as the initiator of the tunnel.
Non-Meraki VPN Failover
For non-Meraki VPN the MX will fail overtheIPSec tunnel from the MXPrimary to Secondary internet link when the link is marked as failed. The primary link can be set under Security & SD-WAN > Configure > SD-WAN & Traffic Shaping page.
Peer Availability
By default, a non-Meraki peer configuration applies to all MX-Zappliances in your dashboard organization. Since it is not always desirable for every appliance you control to form tunnels to a particular non-Meraki peer, the Availability column allows you to control which appliances within your Organization will connect to each peer. This control is based on network tags, which are labels you can apply to your dashboard networks.
When All networksis selected for a peer, all MX-Z appliances in the organization will connect to that peer. When a specific network tag or set of tags is selected, only networks that have one or more of the specified tags will connect to that peer.
More information on network tags can be found in the Organization Overviewarticle.
VPN Firewall Rules
You can add firewall rules to control what traffic is allowed to pass through the VPN tunnel. These rules will apply to outbound VPN traffic to/from from all MX-Z appliances in the Organization that participate in site-to-site VPN. Configuration steps for the rules can be found in the Site-to-site VPN Firewall Rule Behaviorarticle.
Note:VPN Firewall ruleswill not apply to inbound traffic or to traffic that is not passing through the VPN.
Monitoring Site-to-site VPN
You can monitor the status of the site-to-site VPN tunnels between your Meraki devices by clicking Security & SD-WAN > Monitor > VPN Status. This page provides real-time status for the configured Meraki site-to-site VPN tunnels. It lists the subnet(s) being exported over the VPN, connectivity information between the MX-Z appliance and the Meraki VPN registry, NAT Traversal information, and the encryption type being used for all tunnels. For more information regarding this page,refer to theVPN Status Pagearticle.
Troubleshooting
Refer to Site-to-site VPN Troubleshootingfor common issues and troubleshooting steps.
