Sonicwall Site-To-Site, MPLS and VPN

Posted on 2013-12-19
Last Modified: 2014-01-07

we have multiple branch offices which we want to connect using Sonicwall router. There is a NSA-2400 at our main location and NSA220 at the remote branches.
We have a MPLS network and we want to create a backup vpn via internet. Via MPLS the packets should be transferred without a vpn connection.

Since the firewall is working zone based, depending on which route is active, the packets either enter or leave through the VPN zone or MPLS zone (X2).

How can I set this up to create access rules only once and not twice (for zones MPLS and VPN)?

Question by:acbxyz
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LVL 11

Expert Comment

ID: 39729481
Did you check the "Failover and LB" under network tab.

Also create floating routes with two separate metrics and setting "Disable route when the interface is disconnected".

LVL 10

Author Comment

ID: 39729856
You misunderstood. Routing is not the problem.
My problem is that I want to use the firewall to allow only specific services to specific hosts. And I want to define the rules only once, not twice for both possible ways.
LVL 25

Expert Comment

by:Diverse IT
ID: 39730474
Hi acbxyz,

I configure this exact scenario with Static Routes and Network Monitor Probes. If that sounds OK with you let me know and I'll provide the instruction.

The goal is when the primary connection between the two sites (direct or MPLS) fails, traffic would automatically be routed through a s2s VPN (policy based)...correct?

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LVL 10

Author Comment

ID: 39735045
sorry for late response.
I've tested and read a lot more and I have to revoke the s2s as we want to use the vpn connection always for some traffic since it has more bandwidth - with worse latency and jitter, but for e.g. printer it's unimportant). So I think we need to set up the vpn with tunnel interfaces and route some services (especially 9100/tcp) that way
So routing on the main office will be:
1. source:, dest:, service: printing, interface: tun0, disable when interface is disconnected (checked)
2. source:, dest:, service: any, interface: X2, gateway: router mpls provider, either with probe or ospf
3. source:, dest:, service: any, interface: tun0
4. route to drop tunnel (?)

But it doesn't answer the question I have here.
Is it necessary to add the same firewall rules in LAN to MPLS and LAN to VPN as well as MPLS to LAN and VPN to LAN
LVL 25

Expert Comment

by:Diverse IT
ID: 39741181
First you have to answer our questions so that we can communicate on this. You still have not answered mine previously so I can only assume here, but this is what I think you are trying to achieve.

Here is a below example diagramExample DiagramBefore defining the methods to configure the failover, the following factors are assumed to be in place:
1. That a site to site VPN has been configured correctly and tunnel is up.
2. That a direct or MPLS connection exists between Site A and Site B.
3. That although a direct connection exists between Site A and Site B, traffic is passing to the other side over the VPN tunnel.

The configuration for failover

Create a probe-dependent static route to route all traffic destined to the remote MPLS network. This route would take precedence over the VPN route. The probe target should be the IP address of the MPLS router on the other side. The probe target is defined by creating a Network Monitor Policy under Network > Network Monitor.

A separate route should be created defining the path to take to reach the probe target. Network Monitor Policy would probe the target regularly. Failure of the MPLS connection would also result in the failure of the probe target. When the probe fails, SonicWALL would disable the static route thus allowing the VPN kernel routes (hidden) to take precedence.

When the probe target is reachable again, the static route would be re-enabled, forcing traffic over the MPLS connection.

1. Create Address Objects

Create the following address objects under Network > Address Objects and group them.
NSA 2400 LAN Network
NSA 220 LAN Network
NSA 2400 DMZ Network
NSA 220 DMZ NetworkAddress Group on NSA 220Address Group on NSA 2400NSA 2400 DMZ Gateway
NSA 220 DMZ Gateway
NSA 2400 MPLS Router
NSA 220 MPLS RouterMPLS Router on the NSA 2400MPLS Router on the NSA 220DMZ Gateway on the NSA 2400DMZ Gateway on the NSA 220

2. Create a Network Monitor Policy

The probe target is defined by creating a Network Monitor Policy under Network > Network Monitor.
Network Monitor pageNetwork Probe on the NSA 2400Network Probe on the NSA 220Network Monitor page on the NSA 2400 if target is aliveNetwork Monitor page on the NSA 2400Network Monitor page on the NSA 220 if target is aliveNetwork Monitor page on the NSA 220

3. Create Static Routes

Create a static route to route traffic to the probe target. (Network > Routing)Route 1 on NSA 2400Route 1 on NSA 220Create a static route to pass all traffic over the direct connection with probing enabled.Route 2 on NSA 2400Route 2 on NSA 220

4. Here's How to Test

On creating the routes traffic would be forwarded through the direct or MPLS connection. The site to site VPN policy would still show as up with a green light. To test whether failover and fallback  is functioning as intended, perform the following:

1. Disconnect, either physically or logically, the MPLS connection.
2. The Network Monitor policy will become inactive as the probing defined in the policy to the probe target will fail.
3. Consequent to the probe failure, the static route created to route traffic to the other side will be disabled.
4. When the static route is disabled, the VPN kernel routes will be re-enabled and traffic will be forwarded over the VPN tunnel.
5. Re-connect the MPLS connection.
6. The Network Monitor policy will become active again as the probing defined in the policy is successful.
7. When the probe succeeds the static route will be re-enabled automatically.
8. As static route takes precedence over VPN routes, traffic will again be routed through the direct or MPLS connection.Let me know how it goes!

P.S. The images mention NSA 240 but just substitute them for NSA 220 - all applies in the same manner.
LVL 10

Author Comment

ID: 39758864
Thanks for that guide, but this is what I've got working a long time.

I don't use a network probe since network routes through mpls are distributed via ospf. This is working great.
I don't use a group of network addresses because the priority isn't working correctly besides the subnet routes I get via ospf from the cisco routers of our isp.

And now I ask the fourth time in this thread, what about the firewall?
Auto-Added rules are deactivated. These always allow the whole subnets for all services. We want to configure it as "from ip", "to ip", "these services". While sonicwall is using the zones and vpn is a fixed zone, do we have to define the same rules twice per router?
LVL 25

Accepted Solution

Diverse IT earned 500 total points
ID: 39758883
Yes, you'd have to do them twice. There is no way, that I know of, otherwise.

P.S. you have asked three times about Access Rules and each time you allude to a different aspects of's a bit difficult to ascertain what you have been trying to ask with the way you word your questions.
LVL 11

Expert Comment

ID: 39760375
Ten words mightier than 1000 words with diagrams.

The nice documentation deserved some mercy.

I actually saved it for later reference. Thank you.
LVL 25

Expert Comment

by:Diverse IT
ID: 39763268
You're welcome, glad someone appreciates the effort! jeeze! lol

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