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    Quick Snort Setup Instructions for New Users

    Scheduled Pinned Locked Moved IDS/IPS
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    • S
      Supermule Banned
      last edited by

      Alias Group??? Where in the GUI is that Bill?

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      • bmeeksB
        bmeeks
        last edited by

        @Supermule:

        Alias Group??? Where in the GUI is that Bill?

        You can create an Alias that has other Aliases in it.  Under Firewall…Aliases.  Attached are two screenshots showing my whitelist alias group.  Click the (e) to edit the alias.  Then on the next screen click the (+) icon to add more entries to the alias (in effect making it an Alias Group).

        Bill

        whitelist_alias_group.jpg
        whitelist_alias_group.jpg_thumb
        Alias_group_edit.jpg
        Alias_group_edit.jpg_thumb

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        • S
          Supermule Banned
          last edited by

          This is great!! Thx ;)

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          • bmeeksB
            bmeeks
            last edited by

            Here is the Whitelist entry itself.  Notice the Alias down at the bottom is the one created in the previous screenshots.

            Bill

            whitelist.jpg
            whitelist.jpg_thumb

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            • S
              Supermule Banned
              last edited by

              I understand! Thx mate. Really appreciated!

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              • bmeeksB
                bmeeks
                last edited by

                @Supermule:

                I understand! Thx mate. Really appreciated!

                You're welcome. I just used some quick and dirty names for example, but you could name things logically and perhaps create a "WAN_whitelist_hosts" Alias and then others for different interfaces.  As I said, Aliases are very powerful tools once you get the hang of using them.

                Bill

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                • S
                  Supermule Banned
                  last edited by

                  I have named it Snort Friendly IP :D

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                  • bmeeksB
                    bmeeks
                    last edited by

                    @vipermy:

                    First of all, sorry if it's a noob question. We use pfSense as inter-department firewall within private network. We could install snort package through pfSense proxy setting. However, we couldn't perform the snort rule update. Is there anyway we could set the proxy snort update and how? or how to perform snort rule update manually?

                    FYR, we are using pfSense 2.0.3 with Snort 2.9.4.6 pkg v. 2.5.9

                    Thank you in advance.

                    Sent you a PM with my e-mail address.  Reply back to the address and I will send you a patched file I would like for you to test for me.  I think it will allow Snort rule updates through the pfSense system proxy.

                    Bill

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                    • M
                      Mr. Jingles
                      last edited by

                      Thank you both for the explanations, I learned something valuable  ;D

                      6 and a half billion people know that they are stupid, agressive, lower life forms.

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                      • M
                        Mr. Jingles
                        last edited by

                        Could I ask a question about the oinkcode?

                        I purchased a subscription, but I am not quite sure if I understand the GUI correctly now.

                        Before, the last couple of months, when I didn't have a subscription, I flagged 'install snort community rules' (obviously, since they are free  ;D) and also enabled them on both interfaces (for/ex: WAN-categories -> Select the rulesets Snort will load at startup -> Snort GPLv2 Community Rules (VRT certified)).

                        But now that my oinkcode stands for a paid subscription, do I still have to select 'install snort community rules', or is just selecting the right 'IPS-policy' sufficient? I ask, since specifically now I don't see any alerts in my Snort-log anymore.

                        Thank you for your answer  ;D

                        6 and a half billion people know that they are stupid, agressive, lower life forms.

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                        • bmeeksB
                          bmeeks
                          last edited by

                          @Hollander:

                          Could I ask a question about the oinkcode?

                          I purchased a subscription, but I am not quite sure if I understand the GUI correctly now.

                          Before, the last couple of months, when I didn't have a subscription, I flagged 'install snort community rules' (obviously, since they are free  ;D) and also enabled them on both interfaces (for/ex: WAN-categories -> Select the rulesets Snort will load at startup -> Snort GPLv2 Community Rules (VRT certified)).

                          But now that my oinkcode stands for a paid subscription, do I still have to select 'install snort community rules', or is just selecting the right 'IPS-policy' sufficient? I ask, since specifically now I don't see any alerts in my Snort-log anymore.

                          Thank you for your answer  ;D

                          The paid subscription Oinkcode automatically includes the "Snort Community Rules" in the downloaded rule set, so you do not need to manually select those anymore.

                          Just check the Snort VRT rules (and optionally Emerging Threats if you want some of those), then choose an IPS Policy.  You will get the Community Rules this way.

                          Bill

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                          • J
                            jdsilva
                            last edited by

                            I have snort up and running. I subscribed to the VRT rules. However when I added my oinkcode, it doesn't seem to download the latest subscriber rules. For example I ran the update today, and it downloaded snortrules-snapshot-2946.tar.gz Sept 3. It should have downloaded snortrules-snapshot-2950.tar.gz

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                            • bmeeksB
                              bmeeks
                              last edited by

                              @jdsilva:

                              I have snort up and running. I subscribed to the VRT rules. However when I added my oinkcode, it doesn't seem to download the latest subscriber rules. For example I ran the update today, and it downloaded snortrules-snapshot-2946.tar.gz Sept 3. It should have downloaded snortrules-snapshot-2950.tar.gz

                              No, the binary version of Snort is considered when downloading rule updates.  The rules are coded for the different binary versions.  Snort on pfSense is currently version 2.9.4.6, so you will download the 2.9.4.6 rules snapshot.  The rules usually update on Tuesday and Thursday over at Snort.org.

                              An update to the 2.9.5.5 Snort binary for the pfSense Snort package should come out late this month or early in November.  Testing it now.

                              Bill

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                              • C
                                coolcat1975
                                last edited by

                                Hi!

                                I am using policy connectivity.
                                I am getting false positives for ssp_ssl: Invalid Client HELLO after Server HELLO Detected.

                                How can i disable this policy when using policy?

                                best regards

                                Karl

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                                • bmeeksB
                                  bmeeks
                                  last edited by

                                  @coolcat1975:

                                  Hi!

                                  I am using policy connectivity.
                                  I am getting false positives for ssp_ssl: Invalid Client HELLO after Server HELLO Detected.

                                  How can i disable this policy when using policy?

                                  best regards

                                  Karl

                                  You can't easily disable this directly because it is a preprocessor alert.  I've seen some traffic about this alert on the Snort mailing list that indicates it is a potential bug in the preprocesor code.

                                  The best workaround for now is to create a Suppress List entry for this alert.  On the ALERTS tab, click the little plus sign (+) next to the alert's GID:SID.  This will automatically add it to the Suppress List and you won't get blocks on those IPs.  You will still see the alert in the ALERTS tab, but it will not block the offending IP.

                                  After adding the Suppress entry, restart Snort on the affect interface.

                                  Bill

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                                  • C
                                    coolcat1975
                                    last edited by

                                    hi!

                                    thanks for your answer.

                                    i am aware about the supress function but best practice says that you should disable the rule.

                                    anyway: i will test supressing as all alerts are forwarded to icinga. i hope this will also be supressed

                                    greetings

                                    karl

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                                    • bmeeksB
                                      bmeeks
                                      last edited by

                                      @coolcat1975:

                                      hi!

                                      thanks for your answer.

                                      i am aware about the supress function but best practice says that you should disable the rule.

                                      anyway: i will test supressing as all alerts are forwarded to icinga. i hope this will also be supressed

                                      greetings

                                      karl

                                      Disabling is the best, but with today's hardware capability just suppressing is fine.  That's the answer you generally get from the Snort VRT folks as well.  Maybe if you are inspecting 1 Gbit/sec plus traffic loads, the distinction between disabling and suppressing matters; but for most folks with modern hardware there is no meaning difference.

                                      Bill

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                                      • C
                                        coolcat1975
                                        last edited by

                                        Just another question:

                                        If snort is bound to Interface WAN and pfsense is in transparent mode, how is snort working when blocking is activated?

                                        does snort drop the packet and blocks the ip or is the packet passed and then the ip is blocked?

                                        regards

                                        karl

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                                        • bmeeksB
                                          bmeeks
                                          last edited by

                                          @coolcat1975:

                                          Just another question:

                                          If snort is bound to Interface WAN and pfsense is in transparent mode, how is snort working when blocking is activated?

                                          does snort drop the packet and blocks the ip or is the packet passed and then the ip is blocked?

                                          regards

                                          karl

                                          I honestly don't know the answer to that question.  I've never tested Snort on pfSense in Transparent Mode.  I suspect the traffic will still get blocked because Snort actually uses the packet filter engine and its tables to insert blocks.  In that sense it operates just like the firewall module itself.

                                          Where Snort might get tripped up in Transparent Mode is with the defintion of $HOME_NET and $EXTERNAL_NET variables.

                                          Bill

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                                          • S
                                            sebna
                                            last edited by

                                            Hi,

                                            Thanks for great guide.

                                            Before I found it I just went through all the options and configured as I thought it makes sense to my limited knowledge and I did one thing differently.

                                            I went to my defined WAN interface in snort -> Wan Rules -> selected from drop down GPLv2 rules and pressed on enable all rules in the current category as they were all greyed out before that and seemed inactive - is this necessary step and what it actually means if I leave all of them greyed out and what it means if I enable them.

                                            Also in point

                                            20.  If you followed my advice for Snort VRT rules, this page is easy.  Just click the check box for "Use IPS Policy" and then select "Connectivity" in the drop-down.  Click Save and you're done!  Once you gain some experience with Snort, you can come back and choose one of the other two more restrictive policies.  I personally run "Balanced", but it will require some tuning if run in blocking mode.

                                            If I only registered an account (without a paid subscription) to get access to GPL rules should I tick or leave the "Use IPS Policy" box unticked?

                                            If I have mail server, DNS, DHCP and SQL server on my LAN should I define the names in WAN Variables and if yes what is the correct syntax? Can it be IP or is it a FQN

                                            Thank you for explaining any of the above.

                                            seb

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