Snort 2.9.4.1 pkg v.2.5.8
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2.1-BETA1 (amd64)
built on Fri May 17 16:45:31 EDT 2013
FreeBSD 8.3-RELEASE-p8
Snort v2.9.4.1 pkg v. 2.5.8Hello,
Ever since I enabled Snort on my LAN interface, my firewall logs have been flooded with the alerts on the attached screen shot. Is there any way to get rid of these alerts? I've been running snort just on the WAN interface for a few good months now and never had these alerts on the firewall logs before. I started to test Snort on the LAN interface a couple of days ago and noticed my firewall log was full of those alerts. I do have IPv6 disabled on the WAN and LAN interfaces. BTW, thanks for this package bmeeks you’ve done a great job with it.
Traffic on port 1900 to that destination IPv6 address is SSDP (Simple Service Discovery Protocol) traffic. Snort does not, to the best of my knowledge, generate such traffic and has no need for it. I would say this is not related to enabling Snort on the LAN.
Bill
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thanks Bill for your answer…but its weird, if I disable Snort on the LAN interface, those log entries stop and only return if I enable Snort on the LAN interface again.
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So to sum up my answer to your question, if had 2GB or more of RAM and not a lot of load (say less than 50 Mbits/sec) with a reasonably modern CPU; then I would just run the default preprocessor setup on both interfaces.
Thank you Bill for your clear and concise reply. Snort has jumped in leaps and bounds since you started contributing and adding to Ermal's package. ;D
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I have no choice with referring to torrent or p2p blocking 2with snort. With current version, without blocking the client who is downloading using torrent software. Not much can be done as the client kept continue downloading the file without failure. I have try it with my notebook , even though snort manage to block some external IP (using both LAN and WAN setting) , my torrent software keep continue downloading as nothing blocking it at all.
I do understand that with the setting I intended to used , my client or some workstation will be accidentally block(if they forgot to shut off their torrent software. But it sort like reminder to the client not to use torrent software in my network. After all with cron , it will only block for 5 min. So the client must make sure their pc is according to my requirement within 5 minute.
Really appreciate if the whitelist issue can be settle.
Thanks for the new snort interface.
Ok , my problem is…..
Base on my understanding with snort blocking capabilities
LAN setting - I can block both LAN@internal and External IP with selection of new whitelist setting which i have uncheck the "Add firewall Local Networks to the list (excluding WAN)." option. Block setting "both"
WAN setting - I can block external setting , wth default whitelist setting. Block setting "both"Both LAN and WAN setting will have different categories selection base on my need and requirement.
For the above setting , I manage to
WAN Setting - block external IP
LAN Setting - block only external IP (supposely to block both internal@LAN ip and external IP)When I view the whitelist IP with "view list" function , in the new whitelist setting, the local IP still there , sort nothing happened with the uncheck action I have done?
Bug? or I missed something?
4 am here, since yesterday morning, I will need to have some rest first. Really appreciate if any one can advice me the next action.
I went back and looked at the code. Currently it is by design that the interface Snort is running on (except when it's the WAN) is always added to HOME_NET and the WHITELIST. Do you really want to block your local LAN IP addresses? If so, why? You can easily lock yourself out of the firewall this way (at least lock out a workstation). It has always been the behavior of Snort to add the interface running Snort to HOME_NET and the WHITELIST. What changed in this last update was instead of whitelisting the entire WAN subnet, only the WAN IP is whitelisted. The checkbox just adds all the other locally attached firewall networks to HOME_NET and the WHITELIST. Formerly these were not added by default.
Bill
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I have no choice with referring to torrent or p2p blocking 2with snort. With current version, without blocking the client who is downloading using torrent software. Not much can be done as the client kept continue downloading the file without failure. I have try it with my notebook , even though snort manage to block some external IP (using both LAN and WAN setting) , my torrent software keep continue downloading as nothing blocking it at all.
I do understand that with the setting I intended to used , my client or some workstation will be accidentally block(if they forgot to shut off their torrent software. But it sort like reminder to the client not to use torrent software in my network. After all with cron , it will only block for 5 min. So the client must make sure their pc is according to my requirement within 5 minute.
Really appreciate if the whitelist issue can be settle.
I can make the change, but I have to figure out a way to incorporate it so it does not break existing settings for folks who do not want to use it in the same manner. I will put this on the To-Do list for the next release. I will alter the WHITELIST so the Local Networks (including the interface Snort is running on) are not automatically included when the new Checkbox is cleared.
In the meantime, I can show you how to modify the default behavior on your system if you will PM (Private Message) me.
Bill
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thanks Bill for your answer…but its weird, if I disable Snort on the LAN interface, those log entries stop and only return if I enable Snort on the LAN interface again.
OK, I will do a little research and see if something pops up. I don't use IPv6 on my systems yet, so I have never seen this traffic.
Bill
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I have no choice with referring to torrent or p2p blocking 2with snort. With current version, without blocking the client who is downloading using torrent software. Not much can be done as the client kept continue downloading the file without failure. I have try it with my notebook , even though snort manage to block some external IP (using both LAN and WAN setting) , my torrent software keep continue downloading as nothing blocking it at all.
I do understand that with the setting I intended to used , my client or some workstation will be accidentally block(if they forgot to shut off their torrent software. But it sort like reminder to the client not to use torrent software in my network. After all with cron , it will only block for 5 min. So the client must make sure their pc is according to my requirement within 5 minute.
Really appreciate if the whitelist issue can be settle.
I can make the change, but I have to figure out a way to incorporate it so it does not break existing settings for folks who do not want to use it in the same manner. I will put this on the To-Do list for the next release. I will alter the WHITELIST so the Local Networks (including the interface Snort is running on) are not automatically included when the new Checkbox is cleared.
In the meantime, I can show you how to modify the default behavior on your system if you will PM (Private Message) me.
Bill
Thanks will PM you now
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thanks Bill for your answer…but its weird, if I disable Snort on the LAN interface, those log entries stop and only return if I enable Snort on the LAN interface again.
OK, I will do a little research and see if something pops up. I don't use IPv6 on my systems yet, so I have never seen this traffic.
Bill
No worries Bill, I got the firewall to stop logging IPv6 multicast, no need to look into this, thanks
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No worries Bill, I got the firewall to stop logging IPv6 multicast, no need to look into this, thanks
OK. I never did find any connection in my Google research between SSDP and Snort. There is one possibility, though, that just occurred to me. Snort puts the interface it is running on in promiscuous mode. Perhaps that is why you suddenly started seeing the traffic when Snort was enabled on the interface.
Just not logging it should be fine.
Bill
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Just posting to confirm that the blank page problem has been resolved.
Thank you ;D
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The new gui is very nice. The viewing of the whitelist defaults was very helpful in making sure it was getting the list that I wanted to make sure something important didn't get blocked.
Nice job!
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I am getting a bunch of unimportant alerts on the LAN from an ipv6 address (it is actually a dhcp solicit request to port 547). This is the first time putting an ipv6 address in the suppression list so I don't know if this is new behavior or not. I have already upgraded all my installations to 2.5.8 package but I have a feeling older packages have the same issue though.
06/14/13 15:15:37 2 Attempted Information Leak fe80::344b:2f8a:dc36:80e5 ff02::c 122:23 (portscan) UDP Filtered Portsweep
I tried adding the ipv6 address to suppress fe80::344b:2f8a:dc36:80e5 ff02::c but it gets written to the interface suppression file incorrectly which causes snort to not start up…
#(portscan) UDP Filtered Portsweep
suppress gen_id 122, sig_id 23, track by_src, ip fe80::344b:2f8a:dc36:80e5I really don't want to ignore the scan completely. I would just modify the suppression file directly but it will get overwritten on the next time the suppression file gets written to disk.
UPDATE: Even if I manually edit the suppresion file for the interface the gui seems to overwrite it with the corrupt line when I try even starting the snort instance on that interface. It was worth a try anyway.
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I am getting a bunch of unimportant alerts on the LAN from an ipv6 address (it is actually a dhcp solicit request to port 547). This is the first time putting an ipv6 address in the suppression list so I don't know if this is new behavior or not. I have already upgraded all my installations to 2.5.8 package but I have a feeling older packages have the same issue though.
06/14/13 15:15:37 2 Attempted Information Leak fe80::344b:2f8a:dc36:80e5 ff02::c 122:23 (portscan) UDP Filtered Portsweep
I tried adding the ipv6 address to suppress fe80::344b:2f8a:dc36:80e5 ff02::c but it gets written to the interface suppression file incorrectly which causes snort to not start up…
#(portscan) UDP Filtered Portsweep
suppress gen_id 122, sig_id 23, track by_src, ip fe80::344b:2f8a:dc36:80e5I really don't want to ignore the scan completely. I would just modify the suppression file directly but it will get overwritten on the next time the suppression file gets written to disk.
UPDATE: Even if I manually edit the suppresion file for the interface the gui seems to overwrite it with the corrupt line when I try even starting the snort instance on that interface. It was worth a try anyway.
Thanks for reporting. That definitely looks like a bug. I will get it fixed and included in the new 2.5.9 update I am working on. This update will include the 2.9.4.6 binary upgrade of Snort itself, and the 2.5.9 GUI package update will include some new features. I will figure out this Suppress List bug with IPv6 and include that fix as well.
Update – after looking at what is written to the Suppress List, it dawned on me what the problem is. I added a "fix" to allow wrapping of the long IPv6 addresses in the Alerts tab columns. What I had to do is provide a zero-length space in the IPv6 string to give the browser a line break opportunity for word wrapping. I put one of those codes at each colon in the address. That's what the code is. So I inadvertently introduced this problem. I will get it fixed, but would rather just include it in the 2.5.9 update mentioned above. That will be coming out before July.
Until then you should be able to manually edit the list. First, open the list on the Suppress List tab, click the edit icon, then delete any bogus entries. Save the list. Then manually add the information. It should not get overwritten again unless you click the plus ( + ) icon on the Alerts tab to automatically add another entry.
Bill
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Until then you should be able to manually edit the list. First, open the list on the Suppress List tab, click the edit icon, then delete any bogus entries. Save the list. Then manually add the information. It should not get overwritten again unless you click the plus ( + ) icon on the Alerts tab to automatically add another entry.
If I create the entire supression line manually through the gui it still gets saved incorrectly. Try it yourself…
I will just suppress the entire rule for now until your next major version comes out (2.5.9). Thanks.
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Until then you should be able to manually edit the list. First, open the list on the Suppress List tab, click the edit icon, then delete any bogus entries. Save the list. Then manually add the information. It should not get overwritten again unless you click the plus ( + ) icon on the Alerts tab to automatically add another entry.
If I create the entire supression line manually through the gui it still gets saved incorrectly. Try it yourself…
I will just suppress the entire rule for now until your next major version comes out (2.5.9). Thanks.
That's strange and unexpected. I will try to reproduce. Tell me the steps you did to get the error:
I assume click on an alert from the Alerts tab to auto-add to the Suppress List ?
Bill
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I clicked on the add id to supress list in the alert log which works fine but does not have an IP address in it (which is normal).
Stop and restart snort works fine.
I then went to the suppress list page
I then clicked on e to edit the LAN suppress list.
I edited it through the gui to add ', track by_src, ip fe80::344b:2f8a:dc36:80e5' to the end of the autogenerated entry.
I then click save.
It brings me back to the suppress listing page
I click on e button to edit the list and it displays the ipv6 address all messed up again. -
I clicked on the add id to supress list in the alert log which works fine but does not have an IP address in it (which is normal).
Stop and restart snort works fine.
I then went to the suppress list page
I then clicked on e to edit the LAN suppress list.
I edited it through the gui to add ', track by_src, ip fe80::344b:2f8a:dc36:80e5' to the end of the autogenerated entry.
I then click save.
It brings me back to the suppress listing page
I click on e button to edit the list and it displays the ipv6 address all messed up again.Did you "copy and paste" the IP address into the list? If so, that's what happened. It copied in the "invisible" zero-length space codes. They do not display, but are picked up in the copied string text. I can put a "filter" on the Suppress List page to get rid of them prior to saving.
I can also see about adding an option to auto-add the "track by_src" kind of Suppress List entry. I will add a little plus (+) icon beside the existing (x) icon under the IP addresses in the Alerts tab. Clicking the (+) icon will add the IP address to the Suppress List.
Bill
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I am not sure about pasting. I will try to VPN in and try both methods either late tonight or tomorrow.
by_src option from the GUI would be nice.
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I am not sure about pasting. I will try to VPN in and try both methods either late tonight or tomorrow.
by_src option from the GUI would be nice.
by_src will be added. It's an easy addition that I just had not thought about. If you type in the IPv6 address and don't paste it, then you should be OK. Although it could be that the Suppress List is now corrupted with the bogus characters. It might have to be "wiped" and reloaded.
I'm very, very close to having the 2.5.9 package ready to submit to the Core Dev Team for review. I might be able to get it posted by the end of the weekend or very early next week for them to review.
Bill
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I will try to look at it in the next 2 hours or so then so that I can report the results back to you quicker.
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It is copy / paste that causes it. I typed it in manually in the web GUI and viewed it after saving and it was not messed up. I started and stopped the service without issues afterwards too.
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It is copy / paste that causes it. I typed it in manually in the web GUI and viewed it after saving and it was not messed up. I started and stopped the service without issues afterwards too.
Thanks. I can add a filter-before-save step in the Suppression List tab so any zero-length spaces that get pasted in will be removed during the save.
Bill
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Sounds great.
I am curious.. Is there a way to deal with the copy including extra hidden characters? I only say that because I copied it into another program but now I am wondering if that document has these extra hidden characters in there too. I wonder if a copy into gnome editor for an example would strip them out during a paste into the gnome editor or not.
I don't expect anything to be done… I am just interested in knowing how things like that could be dealt with if the copy needed to be pristine. For example maybe not having the characters in the table if possible which i assume its not. You can ignore this question and I won't feel bad... I am sure you have better things to do :).
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Sounds great.
I am curious.. Is there a way to deal with the copy including extra hidden characters? I only say that because I copied it into another program but now I am wondering if that document has these extra hidden characters in there too. I wonder if a copy into gnome editor for an example would strip them out during a paste into the gnome editor or not.
I don't expect anything to be done… I am just interested in knowing how things like that could be dealt with if the copy needed to be pristine. For example maybe not having the characters in the table if possible which i assume its not. You can ignore this question and I won't feel bad... I am sure you have better things to do :).
I don't know of a way to exclude them from the copy operation since that is totally outside the scope of the Snort GUI.Scratch that first sentence. Should have done a quick Google before I posted it originally. Turns out it is possible to "capture" a copy operation in JavaScript and manipulate the clipboard contents. I will experiment with this approach on the Alerts tab page to see if I can capture and "scrub" the clipboard data of any zero-length space characters before passing the data on to the OS.The zero-length spaces are currently a sort of quasi-necessary evil. Without them, IPv6 addresses are so long they overlap the next column on the tab. There is limited real estate on the screen for all the data required for the Alerts tab. The Widescreen package is not yet standard in pfSense. The default display width is 725 pixels no matter what the total screen width is. So I try to stay within that limit for now until something like Widescreen is incorporated into the baseline pfSense GUI. The zero-length spaces are the best I could come up with to break IPv6 addresses.
I also don't know what other editors will do with them. I do know they come across from your Forum post here to my browser. I copied your IPv6 address example and then pasted it into a PERL regex test web site. The zero-length spaces came over and showed up as the values. So they survived through that process of copying from your post and pasting into another web site's text form.
Bill
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Just a small question regarding that….what if you change the 725px to 80% or 100% instead??
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Guys I updated and lost all my settings - no big deal but now I have an issue with http_inspect.
Constantly sites like google, reddit, imgur, yahoo, youtube…the list goes on... are getting blocked.
Can you please tell me what I am doing wrong with the setup of this and if any of you are seeing the same issues?
I tried to disable it via options but then snort won't start - guessing some WAN categories are dependent on http_inspect starting.
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Just a small question regarding that….what if you change the 725px to 80% or 100% instead??
I am using 100% as the table widths, but when you call in the header and footer includes that constitute the pfSense GUI, you wind up running as a nested table that ends up being 100% of 725 pixels… :(
The good news is once something like the Widescreen package stabilizes and becomes part of the standard GUI, Snort should adapt quite well since all of its width specifications are in percentage.
Bill
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Guys I updated and lost all my settings - no big deal but now I have an issue with http_inspect.
Constantly sites like google, reddit, imgur, yahoo, youtube…the list goes on... are getting blocked.
Can you please tell me what I am doing wrong with the setup of this and if any of you are seeing the same issues?
I tried to disable it via options but then snort won't start - guessing some WAN categories are dependent on http_inspect starting.
There is a check box on the Preprocessors tab at the bottom of the HTTP_INSPECT section that says "disable http_inspect alerts" or something similar. Tick that box. You should then no longer get blocks from HTTP_INSPECT alerts. There is also a new button at the bottom of the page for 2.5.8 that will reset all the preprocessor settings to their defaults. The default for HTTP_INSPECT should be enabled but with alerts disabled.
Attached below are my HTTP_INSPECT settings. You can also automatically add problem alerts to the Suppress List by clicking the plus icons (+) under the alert on the Alerts tab. Once you do this, you will need to stop and restart Snort to pick up the change.
Bill
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Did you see the thread I created about finding a notification script by someone else? I am making good use of it. I only block on the LAN snort instance though. I would get too many notifications on the wan side.
http://forum.pfsense.org/index.php/topic,63418.0.html -
Did you see the thread I created about finding a notification script by someone else? I am making good use of it. I only block on the LAN snort instance though. I would get too many notifications on the wan side.
http://forum.pfsense.org/index.php/topic,63418.0.htmlYes, I saw the post. It is a handy script, but with a number of commercial Snort installations I think it could lead to "information overload" with the number of blocks and unblocks that routinely happen. An improvement might be to filter the events and only send notifications for high priority ones so that you don't get an e-mail flood for something like blocks/unblocks from IPs on the RBN or CIARMY lists.
Bill
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I agree. Currently it would mean that I would get about 1000+ emails a day and I dont have time for that…
It would consume a LOT of space on the mailserver for nothing really.
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Guys I updated and lost all my settings - no big deal but now I have an issue with http_inspect.
Constantly sites like google, reddit, imgur, yahoo, youtube…the list goes on... are getting blocked.
Can you please tell me what I am doing wrong with the setup of this and if any of you are seeing the same issues?
I tried to disable it via options but then snort won't start - guessing some WAN categories are dependent on http_inspect starting.
There is a check box on the Preprocessors tab at the bottom of the HTTP_INSPECT section that says "disable http_inspect alerts" or something similar. Tick that box. You should then no longer get blocks from HTTP_INSPECT alerts. There is also a new button at the bottom of the page for 2.5.8 that will reset all the preprocessor settings to their defaults. The default for HTTP_INSPECT should be enabled but with alerts disabled.
Attached below are my HTTP_INSPECT settings. You can also automatically add problem alerts to the Suppress List by clicking the plus icons (+) under the alert on the Alerts tab. Once you do this, you will need to stop and restart Snort to pick up the change.
Bill
Thanks for that…but I am still getting alerts and blocks for it?
Have changed my settings to be exactly the same as yours and still getting things like this:
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Guys I updated and lost all my settings - no big deal but now I have an issue with http_inspect.
Constantly sites like google, reddit, imgur, yahoo, youtube…the list goes on... are getting blocked.
Can you please tell me what I am doing wrong with the setup of this and if any of you are seeing the same issues?
I tried to disable it via options but then snort won't start - guessing some WAN categories are dependent on http_inspect starting.
There is a check box on the Preprocessors tab at the bottom of the HTTP_INSPECT section that says "disable http_inspect alerts" or something similar. Tick that box. You should then no longer get blocks from HTTP_INSPECT alerts. There is also a new button at the bottom of the page for 2.5.8 that will reset all the preprocessor settings to their defaults. The default for HTTP_INSPECT should be enabled but with alerts disabled.
Attached below are my HTTP_INSPECT settings. You can also automatically add problem alerts to the Suppress List by clicking the plus icons (+) under the alert on the Alerts tab. Once you do this, you will need to stop and restart Snort to pick up the change.
Bill
Thanks for that…but I am still getting alerts and blocks for it?
Have changed my settings to be exactly the same as yours and still getting things like this:
And you did restart Snort after the change, correct?
If you did, and are still getting the alerts, then click on the (+) icon under the SID column on the Alerts tab. That will add the Generator ID:Signature ID for that alert to the Suppress List. After doing this, stop and restart Snort on the Snort Interfaces tab. That should for sure silence the alert.
If you restarted Snort after changing the Preprocessor settings and still got the alerts, post back and let me know. That should have silenced them, and if it did not, I need to investigate that in the code.
Bill
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hmmm right some weird stuff happening now.
I restarted snort under the interfaces tab after checking
Turn off alerts from HTTP Inspect preprocessor. This has no effect on HTTP rules. Default is Checked.
But still getting the IPs blocked for http_inspect.
So as you said I tried to add to the suppress list:
However when I go to the suppress list there is nothing entered?
I am going to try to re-install snort right now and see if that helps! -
hmmm right some weird stuff happening now.
I restarted snort under the interfaces tab after checking
Turn off alerts from HTTP Inspect preprocessor. This has no effect on HTTP rules. Default is Checked.
But still getting the IPs blocked for http_inspect.
So as you said I tried to add to the suppress list:
However when I go to the suppress list there is nothing entered?
I am going to try to re-install snort right now and see if that helps!I do believe you will need to manually create it first. Mine working as I already have suppress list
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okay quick update
uninstalled snort
re-installed it
put all my setting back to how they were.
having the check box ticked for it to not block for http_inspect issues didn't work.
So added that ID to the suppress list as you said - this seems to have worked now.
need any logs from me to see why the http_inspect check box isn't working?
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okay quick update
uninstalled snort
re-installed it
put all my setting back to how they were.
having the check box ticked for it to not block for http_inspect issues didn't work.
So added that ID to the suppress list as you said - this seems to have worked now.
need any logs from me to see why the http_inspect check box isn't working?
With that box checked, you will see the alerts logged on the Alerts tab, but you should not be getting blocks for those IP addresses on the Blocked tab. If you are no longer getting blocks for those IPs listed on the Blocked tab, then the check box is working correctly. It's a bit of a misnomer with the titling. The Alerts tab is really just reading the Snort logs. Snort will log everything. What pfSense calls blocks on the Blocked tab is what Snort calls alerts. A little confusing, probably for new users. When you put something on the Suppress List, it will no longer cause blocks, but will still get logged on the Alerts tab (since the event will be logged by Snort). If you truly do not want to even see the event in the logs, then you have to disable the rule. Your screenshot was of the Alerts tab, so I assume the Blocked tab no longer shows an active block for those hosts listed.
As to the blank Suppress List page, go to the If Settings tab for the WAN interface and post a screenshot of the Suppression List setting in the drop-down near the bottom of the page. Unless you specifically had a name set there, it should be either "default" or "wansuppress".
Bill
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yea the box was checked and the hosts were getting blocked
100% sure on this because as soon as the host ip was on that block list the website in question would stop working.
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Anyone still having issues where a blocked IP is removed from snort2c within a few minutes? I'm banging my head here. I've set it for never expire, disabled log limit and removed the 2 cron jobs. They still disappear. I've done a clean install of snort with my old config.. Only 2 options left are to either wipe all snort settings and start fresh or rebuild my box from iso install..
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Anyone still having issues where a blocked IP is removed from snort2c within a few minutes? I'm banging my head here. I've set it for never expire, disabled log limit and removed the 2 cron jobs. They still disappear. I've done a clean install of snort with my old config.. Only 2 options left are to either wipe all snort settings and start fresh or rebuild my box from iso install..
When the packet filter is reloaded the table "snort2c" will be cleared. This can have many causes and the log file should give clues. It is discussed before.