1
vote
Accepted
How can I block GPSD from communicating out?
I need to make it so nothing goes out on port 2947 at all,
To start with, as far as firewall rules go, GPSD isn't "communicating out" because it's not initiating the connection – gpspipe is....
1
vote
Accepted
What determines if a packet should be routed locally or forwarded?
How does the routing table affect the routing decision?
Internally, it's all made according to the routing table. Linux has an additional routing table, the local table, that has special routes for ...
1
vote
How can I simulate NAT reflection failure with `iptables`?
Add an ordinary 'DROP' rule that blocks 'INPUT' packets from your router's IP address to this port.
Due to the way hairpinning "solves" the underlying problem, all hairpinned connections ...
1
vote
Implementing an OpenVPN "kill switch" with iptables
A short solution
Add an empty group tunnel
Run OpenVPN within this group (with sg tunnel or Group=tunnel for systemd unit)
Use the following rules
# Local traffic is allowed
iptables -A INPUT -i lo ...
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