Netgate Discussion Forum
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Search
    • Register
    • Login

    How to detect a cyber attack

    Scheduled Pinned Locked Moved General pfSense Questions
    28 Posts 9 Posters 4.6k Views
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • A
      akuma1x
      last edited by

      I believe it's recommended to use the gateway provided by your ISP as the monitor IP, since it's the first router/hop before your traffic hits the actual internet. If that's down, it truly means your connection is DOWN.

      Jeff

      1 Reply Last reply Reply Quote 1
      • DerelictD
        Derelict LAYER 8 Netgate
        last edited by

        It depends. Sometimes you want to know that the WAN can actually reach the internet, not just the ISP gateway.

        Chattanooga, Tennessee, USA
        A comprehensive network diagram is worth 10,000 words and 15 conference calls.
        DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
        Do Not Chat For Help! NO_WAN_EGRESS(TM)

        hugoeyngH 1 Reply Last reply Reply Quote 1
        • hugoeyngH
          hugoeyng @Derelict
          last edited by

          @Derelict Instead Google DNS or ISP DNS what IP could I use to monitor? Any suggestion?

          I love pfSense!

          Hugo Eyng
          Datamais Sistemas

          1 Reply Last reply Reply Quote 0
          • KOMK
            KOM
            last edited by

            Perhaps one of your ISPs core routers. Do a traceroute somewhere and see what the second or third hop is.

            hugoeyngH 1 Reply Last reply Reply Quote 1
            • stephenw10S
              stephenw10 Netgate Administrator
              last edited by

              I've never seen an issue using 8.8.8.8 personally.

              The fact that you have some SWAP usage shown in that screenshot shows that at some point you exhausted the RAM. That can make things go waaaay slower.
              Check the Status > Monitoring graphs for memory usage. Does it peak when you see these incidents?

              Steve

              RicoR 1 Reply Last reply Reply Quote 1
              • RicoR
                Rico LAYER 8 Rebel Alliance @stephenw10
                last edited by

                @stephenw10 said in How to detect a cyber attack:

                I've never seen an issue using 8.8.8.8 personally.

                Yeah I like to use 8.8.8.8, 8.8.4.4 and 1.1.1.1 for monitoring too.

                -Rico

                hugoeyngH 1 Reply Last reply Reply Quote 1
                • hugoeyngH
                  hugoeyng @KOM
                  last edited by

                  @KOM Great!

                  I love pfSense!

                  Hugo Eyng
                  Datamais Sistemas

                  1 Reply Last reply Reply Quote 0
                  • hugoeyngH
                    hugoeyng @Rico
                    last edited by

                    @Rico I am not sure but is possible that "You will get false positives using Google's DNS servers." as said @tim-mcmanus.

                    But I liked @KOM suggestion.

                    I love pfSense!

                    Hugo Eyng
                    Datamais Sistemas

                    1 Reply Last reply Reply Quote 0
                    • RicoR
                      Rico LAYER 8 Rebel Alliance
                      last edited by

                      I never heard of Google deliberately dropping ICMP traffic to their DNS Servers and personally I never had any issues with it.

                      WANGW.png
                      WANGW is using 8.8.8.8 atm.

                      -Rico

                      1 Reply Last reply Reply Quote 2
                      • RicoR
                        Rico LAYER 8 Rebel Alliance
                        last edited by

                        Monitoring any ISP router does not really show a reliable route to the Internet.
                        Your ISP could have any routing/peering issue, even if their (core) router is perfectly reachable from your side.

                        -Rico

                        1 Reply Last reply Reply Quote 2
                        • KOMK
                          KOM
                          last edited by

                          It shows you if there is a problem between you and your ISP. Anything past that is out of your control. The whole point of the thing is to be a gateway monitor, not a 5-hops-away monitor. The farther away you monitor, the more likely you will get a false positive of some sort, and I wouldn't want my gateway going down because there is a routing problem many hops away from me.

                          1 Reply Last reply Reply Quote 0
                          • Raffi_R
                            Raffi_
                            last edited by

                            On the monitor IP topic, I agree with @Rico and @stephenw10. I have not had issue so far with google DNS. In fact I switched to Google DNS because I suddenly had issues with my ISP's (third hop router). After months of working fine, we had power failures in the area which I suspect also caused issues with that route on the ISP's network. My gateway was marked as down when it wasn't. Switched to 8.8.8.8 and it's been good since then. Is it a perfect solution? No. Will this happen to you? Probably not, but using a device IP on a specific route on the ISP's network to me seems like trouble. If that route goes down like in my case, the traffic will get rerouted and still reach where it needs to go on the web. But that can't happen if my gateway is marked as down and monitoring action is enabled. Ideally, I would like to be able to put in multiple monitor IPs, so if one is not responding another one could.

                            1 Reply Last reply Reply Quote 1
                            • stephenw10S
                              stephenw10 Netgate Administrator
                              last edited by

                              I will say that whilst I've never seen an issue with it on numerous pfSense installs, including my own, Google respond to ping there more as a courtesy. They could just stop responding. Also when you ping 8.8.8.8 you are hitting a machine via anycast so the service may vary depending on where you are pinging from.

                              Steve

                              Raffi_R 1 Reply Last reply Reply Quote 2
                              • Raffi_R
                                Raffi_ @stephenw10
                                last edited by

                                @stephenw10 said in How to detect a cyber attack:

                                I will say that whilst I've never seen an issue with it on numerous pfSense installs, including my own, Google respond to ping there more as a courtesy. They could just stop responding. Also when you ping 8.8.8.8 you are hitting a machine via anycast so the service may vary depending on where you are pinging from.

                                Steve

                                Let's hope they don't pull the rug out from under us. I think a lot of gateways would be marked as down :)

                                hugoeyngH 1 Reply Last reply Reply Quote 1
                                • hugoeyngH
                                  hugoeyng @Raffi_
                                  last edited by

                                  @Raffi_ said in How to detect a cyber attack:

                                  Let's hope they don't pull the rug out from under us. I think a lot of gateways would be marked as down

                                  I hope so too!

                                  I tried monitoring White House and Pentagon IP´s but it did not succedd.

                                  Those IP´s, I believe, would be the last to be down. :)

                                  Thank you everybody.

                                  I love pfSense!

                                  Hugo Eyng
                                  Datamais Sistemas

                                  Raffi_R A 2 Replies Last reply Reply Quote 1
                                  • Raffi_R
                                    Raffi_ @hugoeyng
                                    last edited by

                                    @hugoeyng said in How to detect a cyber attack:

                                    @Raffi_ said in How to detect a cyber attack:

                                    Let's hope they don't pull the rug out from under us. I think a lot of gateways would be marked as down

                                    I hope so too!

                                    I tried monitoring White House and Pentagon IP´s but it did not succedd.

                                    Those IP´s, I believe, would be the last to be down. :)

                                    Thank you everybody.

                                    haha I hope you don't get a knock on the door from people in black suits.

                                    hugoeyngH 1 Reply Last reply Reply Quote 1
                                    • A
                                      akuma1x @hugoeyng
                                      last edited by

                                      @hugoeyng said in How to detect a cyber attack:

                                      I tried monitoring White House and Pentagon IP´s but it did not succedd.

                                      So, White House Down?

                                      https://www.imdb.com/title/tt2334879/

                                      ☺

                                      Jeff

                                      hugoeyngH 1 Reply Last reply Reply Quote 1
                                      • hugoeyngH
                                        hugoeyng @Raffi_
                                        last edited by

                                        @Raffi_ :))))))

                                        I love pfSense!

                                        Hugo Eyng
                                        Datamais Sistemas

                                        1 Reply Last reply Reply Quote 0
                                        • hugoeyngH
                                          hugoeyng @akuma1x
                                          last edited by

                                          @akuma1x hahaha The first to be under attack. Is not a good idea use it to monitoring. Is more secure using the butcher shop next door IP.

                                          I love pfSense!

                                          Hugo Eyng
                                          Datamais Sistemas

                                          1 Reply Last reply Reply Quote 1
                                          • R
                                            runningboy
                                            last edited by runningboy

                                            In most cases, a cyberattack is almost impossible to notice. This operation takes place instantly and the user does not even understand how the intruders entered the system and control it. This situation happened in the office where I work a few months ago. Cybercriminals tried to get hold of our customer base and spread this information online. They penetrated the network and got all the access codes and passwords from our system, which is why the programs crashed and, by chance, they were unable to commit theft. Since then, we've turned to Cyber ​​Essentials to help protect and support our system from potential threats. I hope this will not happen again.

                                            1 Reply Last reply Reply Quote 1
                                            • First post
                                              Last post
                                            Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.