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What are the rules for Nat and forward in UFW?
Add the following to /etc/ufw/before.rules just before the filter rules. # NAT table rules *nat :POSTROUTING ACCEPT [0:0] # Forward traffic through eth0 – Change to match you out-interface -A POSTROUTING -s 192.168.1.0/24 -o eth0 -j MASQUERADE # don’t delete the ‘COMMIT’ line or these nat table rules won’t # be processed COMMIT
How to uncomment for IPv6 on UFW firewall?
Uncomment for ipv6 if you want. The final step is to add NAT to ufw’s configuration. Add the following to /etc/ufw/before.rules just before the filter rules.
Can you add user rules to UFW route?
It is possible to add user rules of course (of the kind “ufw route allow …”) and they can permit traffic before the default deny is applied, and that will then be routed out as expected. Thanks for contributing an answer to Ask Ubuntu!
When does POSTROUTING occur in UFW routing rules?
It seems that POSTROUTING occurs after the default deny rule is applied – so if something is denied by the default rule, it won’t be nat routed out. It is possible to add user rules of course (of the kind “ufw route allow …”) and they can permit traffic before the default deny is applied, and that will then be routed out as expected.
Which is the default forward policy in UFW?
Most documentation recommends setting DEFAULT_FORWARD_POLICY=”ACCEPT” in /etc/default/ufw, but I didn’t want to just let all the traffic through.
Which is UFW route allow in on eth1?
ufw route allow in on eth1 out on eth2. This will allow all traffic routed to eth2 and coming in on eth1 to traverse the firewall. ufw route allow in on eth0 out on eth1 to 12.34.45.67 port 80 proto tcp. This rule allows any packets coming in on eth0 to traverse the firewall out on eth1 to tcp port 80 on 12.34.45.67.
How to set UFW block rules for incoming only?
To set these block rules for incoming only, you would use sudo ufw deny in 1:22/tcp for example. Alternatively, set for outgoing sudo ufw deny out 1:22/tcp and so on. FYI: in case others have this problem. In the detailed iptables output I noticed the ufw rules are missing in the INPUT, OUTPUT, and FORWARD chains.