Using Open VPN service on XG-7100, prevent LAN clients connecting
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My expectation when using a VPN endpoint on the firewall is that this endpoint will only accept traffic inbound from the WAN interface. How do I manually restrict the traffic that the Open VPN service will accept?
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Your expectation is erroneous.
Block the traffic on the interface(s) that are receiving the traffic you want blocked, such as the LAN interface.
A "guest" interface would look something like this:
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@Derelict I'm not sure I've done a good job of expressing my concern. Can you repeat back to me what you understand my issue to be? I want to make sure that we are harmonized, because it seems like this should be very simple to solve.
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Okay, so here's my beef: a VPN is designed to securely encapsulate private traffic to traverse a public network. Public and private are on opposite sides of the WAN interface. Since the Open VPN service accepts inbound connections from private interfaces, it is not working correctly.
Why does the PFSense implementation of Open VPN go against sane networking theory?
How do I stop the Open VPN from being naughty? Are you really saying I have to implement a ton of firewall rules to make the endpoint behave properly?
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It is simple to solve. If you don't want users on an interface to connect to a service running on the firewall, make a block rule there.
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@Derelict The endpoint should be accepting connections from private subnets by default. Why is it doing that?
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Because that WAN address is just another IP address. You need to block traffic from the inside to it if that's what your requirements are.
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@Derelict well, I'm not trying to block access to the WAN. I'm trying to prevent private subnets from connecting to the Open VPN service.
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That is WAN address. That is not the internet. See the rule set I already posted.
Connections to the OpenVPN server would be blocked by the Reject Guest access to This Firewall rule.
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If you have an OpenVPN server listening on the WAN it is not designed to be connected to from the inside. It is designed to be connected to from the outside.
Actually, that's normal. You can reach any address on the box from any interface, unless you have rules to block it. Don't forget, pfSense is a router, so if it, for example receives a packet with the WAN interface as destination, on the LAN interface, it will forward it appropriately through 0.0.0.0.
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I know it's completely normal. It's @shapelytraffic that is having trouble grasping that concept.
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@Derelict I saw your rules, what are you representing with "guest" network?
If I block LAN access to the WAN then I assume this will have global impact.
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@shapelytraffic said in Using Open VPN service on XG-7100, prevent LAN clients connecting:
@Derelict To be clear, I'm trying to disable connecting from the inside. We discovered this quite by accident.
That behaviour is normal. If you don't want it, create a rule on the LAN interface to block it.
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No. It won't have global impact. Global addresses are not covered in any of those block rules. Traffic that is not specifically blocked will be passed to the internet by the bottom rules passing traffic to destination any. Guest Network in that example is the IP network of the GUEST interface.
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@JKnott my issue is that any other router on the market which provides a VPN endpoint and client install will only accept client traffic from the public side of the WAN. You cannot go in through the outdoor, as it were. So, if this is "a feature" then I ask, why is it that the feature goes against networking standards? But also, do I really need to implement a ton of firewall rules to make the endpoint behave?
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@shapelytraffic said in Using Open VPN service on XG-7100, prevent LAN clients connecting:
Why does the PFSense implementation of Open VPN go against sane networking theory?
It's not against sane networking theory. PfSense is a router. When it receives a packet, it forwards it as appropriate and that includes to it's own interface addresses. There is no difference between that and any other address out on the WAN. You need to block it with a rule on the LAN interface.
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You are making a common mistake in thinking that WAN address and WAN Network is the "internet". It isn't. Destination any is the internet. WAN address is the address currently assigned on the WAN interface. WAN Network is the subnet of the WAN interface address.
It does not go against networking standards. The rule set is doing exactly what it is being instructed to do, pass the traffic to the OpenVPN server running on WAN address. If that is not what you want, block it.
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@shapelytraffic said in Using Open VPN service on XG-7100, prevent LAN clients connecting:
If I block LAN access to the WAN then I assume this will have global impact.
Block access only to the WAN interface address, not everything out on the WAN and beyond. That is you block that specific address and no other.
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@Derelict what are you representing with "guest" network?
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If you were trying to reach the LAN interface address from the WAN, you'd have to create a rule that would allow that. Going the otherway, pfSense allows all traffic from the LAN, out to the Internet, including the WAN interface address. In some other routers, such as Cisco, you'd have to create a rule just to reach the Internet.
