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    BRRABill's Field Report With Linux

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    • BRRABillB
      BRRABill @travisdh1
      last edited by

      @travisdh1 said in BRRABill's Field Report With Linux:

      @BRRABill said in BRRABill's Field Report With Linux:

      QOTD:

      So I installed Ubuntu 16.10 yesterday to set up a Unifi cloud controller.

      I followed some pretty simple directions here which had me "setup the iptables" firewall.
      https://community.ubnt.com/t5/UniFi-Wireless/Step-by-Step-Walkthrough-Set-up-Unifi-Cloud-Controller-v-4-7-6/td-p/1324666

      But I have seen most articles reference ufw as the firewall in Ubuntu, a "front end" for iptables.

      So, can someone explain what the heck these two things are? Are they two separate things that should not be used together?

      ufw was installed but not enabled on my install. Is iptables enabled by default on fresh installs?

      iptables is the user-space application to configure the tables kernel firewall. Almost every Linux based firewall app uses iptables in the background to do it's work. So this ufw is just another way to manage the firewall. Leave it to Ubuntu to do something odd.

      I'd hope a firewall is enabled by default, that it's missing as default in CentOS7-1511 is super annoying.

      The "odd" thing is that when I use ufw to list the rules in place (in iptables) nothing is listed.

      Which makes me wonder if they are separate things...

      travisdh1T 1 Reply Last reply Reply Quote 0
      • travisdh1T
        travisdh1 @BRRABill
        last edited by

        @BRRABill said in BRRABill's Field Report With Linux:

        @travisdh1 said in BRRABill's Field Report With Linux:

        @BRRABill said in BRRABill's Field Report With Linux:

        QOTD:

        So I installed Ubuntu 16.10 yesterday to set up a Unifi cloud controller.

        I followed some pretty simple directions here which had me "setup the iptables" firewall.
        https://community.ubnt.com/t5/UniFi-Wireless/Step-by-Step-Walkthrough-Set-up-Unifi-Cloud-Controller-v-4-7-6/td-p/1324666

        But I have seen most articles reference ufw as the firewall in Ubuntu, a "front end" for iptables.

        So, can someone explain what the heck these two things are? Are they two separate things that should not be used together?

        ufw was installed but not enabled on my install. Is iptables enabled by default on fresh installs?

        iptables is the user-space application to configure the tables kernel firewall. Almost every Linux based firewall app uses iptables in the background to do it's work. So this ufw is just another way to manage the firewall. Leave it to Ubuntu to do something odd.

        I'd hope a firewall is enabled by default, that it's missing as default in CentOS7-1511 is super annoying.

        The "odd" thing is that when I use ufw to list the rules in place (in iptables) nothing is listed.

        Which makes me wonder if they are separate things...

        Wait... Ubuntu.... and more crazy Ubuntu type things. I don't think they enable the firewall by default. They say "Just don't run a service you don't need." instead, don't they?

        BRRABillB DashrenderD 2 Replies Last reply Reply Quote 0
        • BRRABillB
          BRRABill @travisdh1
          last edited by

          @travisdh1 said

          Wait... Ubuntu.... and more crazy Ubuntu type things. I don't think they enable the firewall by default. They say "Just don't run a service you don't need." instead, don't they?

          Well, that's part of m question as well.

          From a little reading, it appears there is no firewall by default, because no ports are open.

          But then all you have to do is add ports into iptables, and that enables it?

          This is why I am confused.

          travisdh1T DashrenderD 2 Replies Last reply Reply Quote 0
          • travisdh1T
            travisdh1 @BRRABill
            last edited by

            @BRRABill said in BRRABill's Field Report With Linux:

            @travisdh1 said

            Wait... Ubuntu.... and more crazy Ubuntu type things. I don't think they enable the firewall by default. They say "Just don't run a service you don't need." instead, don't they?

            Well, that's part of m question as well.

            From a little reading, it appears there is no firewall by default, because no ports are open.

            But then all you have to do is add ports into iptables, and that enables it?

            This is why I am confused.

            Nope. You want a web server on port 80, just install apache2. Done.

            1 Reply Last reply Reply Quote 0
            • DashrenderD
              Dashrender @BRRABill
              last edited by

              @BRRABill said in BRRABill's Field Report With Linux:

              @travisdh1 said

              Wait... Ubuntu.... and more crazy Ubuntu type things. I don't think they enable the firewall by default. They say "Just don't run a service you don't need." instead, don't they?

              Well, that's part of m question as well.

              From a little reading, it appears there is no firewall by default, because no ports are open.

              But then all you have to do is add ports into iptables, and that enables it?

              This is why I am confused.

              No adding ports to iptables doesn't not enable it - you'd have to start the service that enables it, and then open the required ports (I suppose you could do it either one first, but if you don't enable the service, then there is no firewall running)

              BRRABillB 1 Reply Last reply Reply Quote 1
              • BRRABillB
                BRRABill @Dashrender
                last edited by

                @Dashrender said i

                No adding ports to iptables doesn't not enable it - you'd have to start the service that enables it, and then open the required ports (I suppose you could do it either one first, but if you don't enable the service, then there is no firewall running)

                Are you sure about that?

                iptables is just the interface to the firewall, which I think is always running.

                Now, by default, it is allowing everything.

                I set up another fresh droplet for testing, and this is what iptables -L gives me

                Chain INPUT (policy ACCEPT)
                Chain FORWARD (policy ACCEPT)
                Chain OUTPUT (policy ACCEPT)
                
                travisdh1T 1 Reply Last reply Reply Quote 0
                • DashrenderD
                  Dashrender @travisdh1
                  last edited by

                  yep, I'm sure IF the following is correct and the firewall is not enabled by default as mentioned below.

                  @travisdh1 said in BRRABill's Field Report With Linux:

                  Wait... Ubuntu.... and more crazy Ubuntu type things. I don't think they enable the firewall by default. They say "Just don't run a service you don't need." instead, don't they?

                  BRRABillB 1 Reply Last reply Reply Quote 0
                  • BRRABillB
                    BRRABill @Dashrender
                    last edited by

                    @Dashrender said in BRRABill's Field Report With Linux:

                    yep, I'm sure IF the following is correct and the firewall is not enabled by default as mentioned below.

                    @travisdh1 said in BRRABill's Field Report With Linux:

                    Wait... Ubuntu.... and more crazy Ubuntu type things. I don't think they enable the firewall by default. They say "Just don't run a service you don't need." instead, don't they?

                    I think maybe what @travisdh1 meant was that it is enabled, but be default allows everything.

                    Hence, it seeming like it's not actually firewalling anything.

                    @travisdh1 ???

                    And where are all the Ubuntu experts here on ML???

                    travisdh1T 1 Reply Last reply Reply Quote 0
                    • BRRABillB
                      BRRABill
                      last edited by

                      So, in this fresh install, I tried adding a rule in ufw, and it added all sorts of stuff to iptables.

                      So maybe it works the one way, but not the other?

                      DashrenderD 1 Reply Last reply Reply Quote 0
                      • DashrenderD
                        Dashrender @BRRABill
                        last edited by

                        @BRRABill said in BRRABill's Field Report With Linux:

                        So, in this fresh install, I tried adding a rule in ufw, and it added all sorts of stuff to iptables.

                        So maybe it works the one way, but not the other?

                        that's completely possible. Unifi stuff is that way
                        you can update the device with a json file, but it won't update the GUI.

                        BRRABillB 1 Reply Last reply Reply Quote 0
                        • BRRABillB
                          BRRABill @Dashrender
                          last edited by

                          @Dashrender said in BRRABill's Field Report With Linux:

                          @BRRABill said in BRRABill's Field Report With Linux:

                          So, in this fresh install, I tried adding a rule in ufw, and it added all sorts of stuff to iptables.

                          So maybe it works the one way, but not the other?

                          that's completely possible. Unifi stuff is that way
                          you can update the device with a json file, but it won't update the GUI.

                          Actually the Unifi installer made NO changes to iptables.

                          DashrenderD 1 Reply Last reply Reply Quote 0
                          • BRRABillB
                            BRRABill
                            last edited by

                            I mean that adding in one rule in ufw (allwing SSH) added all this to the output of iptables -L

                            Chain INPUT (policy DROP)
                            target     prot opt source               destination
                            ufw-before-logging-input  all  --  anywhere             anywhere
                            ufw-before-input  all  --  anywhere             anywhere
                            ufw-after-input  all  --  anywhere             anywhere
                            ufw-after-logging-input  all  --  anywhere             anywhere
                            ufw-reject-input  all  --  anywhere             anywhere
                            ufw-track-input  all  --  anywhere             anywhere
                            
                            Chain FORWARD (policy DROP)
                            target     prot opt source               destination
                            ufw-before-logging-forward  all  --  anywhere             anywhere
                            ufw-before-forward  all  --  anywhere             anywhere
                            ufw-after-forward  all  --  anywhere             anywhere
                            ufw-after-logging-forward  all  --  anywhere             anywhere
                            ufw-reject-forward  all  --  anywhere             anywhere
                            ufw-track-forward  all  --  anywhere             anywhere
                            
                            Chain OUTPUT (policy ACCEPT)
                            target     prot opt source               destination
                            ufw-before-logging-output  all  --  anywhere             anywhere
                            ufw-before-output  all  --  anywhere             anywhere
                            ufw-after-output  all  --  anywhere             anywhere
                            ufw-after-logging-output  all  --  anywhere             anywhere
                            ufw-reject-output  all  --  anywhere             anywhere
                            ufw-track-output  all  --  anywhere             anywhere
                            
                            Chain ufw-after-forward (1 references)
                            target     prot opt source               destination
                            
                            Chain ufw-after-input (1 references)
                            target     prot opt source               destination
                            ufw-skip-to-policy-input  udp  --  anywhere             anywhere             udp dpt:netbios-ns
                            ufw-skip-to-policy-input  udp  --  anywhere             anywhere             udp dpt:netbios-dgm
                            ufw-skip-to-policy-input  tcp  --  anywhere             anywhere             tcp dpt:netbios-ssn
                            ufw-skip-to-policy-input  tcp  --  anywhere             anywhere             tcp dpt:microsoft-ds
                            ufw-skip-to-policy-input  udp  --  anywhere             anywhere             udp dpt:bootps
                            ufw-skip-to-policy-input  udp  --  anywhere             anywhere             udp dpt:bootpc
                            ufw-skip-to-policy-input  all  --  anywhere             anywhere             ADDRTYPE match dst-type BROADCAST
                            
                            
                            
                            1 Reply Last reply Reply Quote 0
                            • DashrenderD
                              Dashrender @BRRABill
                              last edited by

                              @BRRABill said in BRRABill's Field Report With Linux:

                              @Dashrender said in BRRABill's Field Report With Linux:

                              @BRRABill said in BRRABill's Field Report With Linux:

                              So, in this fresh install, I tried adding a rule in ufw, and it added all sorts of stuff to iptables.

                              So maybe it works the one way, but not the other?

                              that's completely possible. Unifi stuff is that way
                              you can update the device with a json file, but it won't update the GUI.

                              Actually the Unifi installer made NO changes to iptables.

                              considering the instructions you found that had you manually make iptables changes, I'm not surprised - not that the script couldn't include that, they don't so they remain simple to be used on any linux distro or nearly any.

                              1 Reply Last reply Reply Quote 0
                              • travisdh1T
                                travisdh1 @BRRABill
                                last edited by

                                @BRRABill said in BRRABill's Field Report With Linux:

                                @Dashrender said i

                                No adding ports to iptables doesn't not enable it - you'd have to start the service that enables it, and then open the required ports (I suppose you could do it either one first, but if you don't enable the service, then there is no firewall running)

                                Are you sure about that?

                                iptables is just the interface to the firewall, which I think is always running.

                                Now, by default, it is allowing everything.

                                I set up another fresh droplet for testing, and this is what iptables -L gives me

                                Chain INPUT (policy ACCEPT)
                                Chain FORWARD (policy ACCEPT)
                                Chain OUTPUT (policy ACCEPT)
                                

                                That's the "tables is turned off" output.

                                BRRABillB 1 Reply Last reply Reply Quote 0
                                • BRRABillB
                                  BRRABill @travisdh1
                                  last edited by

                                  @travisdh1 said

                                  That's the "tables is turned off" output.

                                  See, I think that is semantics.

                                  tables is turned on, but accepting everything.

                                  Because you don't have to issue any commands, simple add something to iptables

                                  travisdh1T 1 Reply Last reply Reply Quote 1
                                  • travisdh1T
                                    travisdh1 @BRRABill
                                    last edited by

                                    @BRRABill said in BRRABill's Field Report With Linux:

                                    @Dashrender said in BRRABill's Field Report With Linux:

                                    yep, I'm sure IF the following is correct and the firewall is not enabled by default as mentioned below.

                                    @travisdh1 said in BRRABill's Field Report With Linux:

                                    Wait... Ubuntu.... and more crazy Ubuntu type things. I don't think they enable the firewall by default. They say "Just don't run a service you don't need." instead, don't they?

                                    I think maybe what @travisdh1 meant was that it is enabled, but be default allows everything.

                                    Hence, it seeming like it's not actually firewalling anything.

                                    @travisdh1 ???

                                    And where are all the Ubuntu experts here on ML???

                                    Ubuntu does things so odd compared to the rest of the ecosystem (ufw), that many of us only touch it if when we have no other choice.

                                    BRRABillB 1 Reply Last reply Reply Quote 0
                                    • travisdh1T
                                      travisdh1 @BRRABill
                                      last edited by

                                      @BRRABill said in BRRABill's Field Report With Linux:

                                      @travisdh1 said

                                      That's the "tables is turned off" output.

                                      See, I think that is semantics.

                                      I is! I was so confused when I first ran into this.

                                      1 Reply Last reply Reply Quote 0
                                      • BRRABillB
                                        BRRABill @travisdh1
                                        last edited by

                                        @travisdh1 said in BRRABill's Field Report With Linux:

                                        @BRRABill said in BRRABill's Field Report With Linux:

                                        @Dashrender said in BRRABill's Field Report With Linux:

                                        yep, I'm sure IF the following is correct and the firewall is not enabled by default as mentioned below.

                                        @travisdh1 said in BRRABill's Field Report With Linux:

                                        Wait... Ubuntu.... and more crazy Ubuntu type things. I don't think they enable the firewall by default. They say "Just don't run a service you don't need." instead, don't they?

                                        I think maybe what @travisdh1 meant was that it is enabled, but be default allows everything.

                                        Hence, it seeming like it's not actually firewalling anything.

                                        @travisdh1 ???

                                        And where are all the Ubuntu experts here on ML???

                                        Ubuntu does things so odd compared to the rest of the ecosystem (ufw), that many of us only touch it if when we have no other choice.

                                        It seems to be a very common choice for many things, though. Even here at ML (such as XO).

                                        travisdh1T 1 Reply Last reply Reply Quote 0
                                        • travisdh1T
                                          travisdh1 @BRRABill
                                          last edited by

                                          @BRRABill said in BRRABill's Field Report With Linux:

                                          @travisdh1 said in BRRABill's Field Report With Linux:

                                          @BRRABill said in BRRABill's Field Report With Linux:

                                          @Dashrender said in BRRABill's Field Report With Linux:

                                          yep, I'm sure IF the following is correct and the firewall is not enabled by default as mentioned below.

                                          @travisdh1 said in BRRABill's Field Report With Linux:

                                          Wait... Ubuntu.... and more crazy Ubuntu type things. I don't think they enable the firewall by default. They say "Just don't run a service you don't need." instead, don't they?

                                          I think maybe what @travisdh1 meant was that it is enabled, but be default allows everything.

                                          Hence, it seeming like it's not actually firewalling anything.

                                          @travisdh1 ???

                                          And where are all the Ubuntu experts here on ML???

                                          Ubuntu does things so odd compared to the rest of the ecosystem (ufw), that many of us only touch it if when we have no other choice.

                                          It seems to be a very common choice for many things, though. Even here at ML (such as XO).

                                          Yes, because it's what the devs use instead of a sane environment (Debian, CentOS). Running things on a different distribution when the devs don't know what's broken is a pain, and huge time sink.

                                          1 Reply Last reply Reply Quote 1
                                          • BRRABillB
                                            BRRABill
                                            last edited by

                                            Another interesting tidbit...

                                            I couldn't get it to stick on reboots with my other install, but it now seems to be sticking.

                                            Uh, Linux. Er, Ubuntu.

                                            1 Reply Last reply Reply Quote 0
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