Snort Updated to 2.7

AhnHEL

I've gotten that type of error in the past. X out any blocked IPs in the Blocked tab, Clear the log on the Alerts tab, and hit Save again in the Categories tab. Also, if you're using a majority of the categories, read page 1 of this post on using ac-bnfa mode. Mine craps out when using ac mode and using a lot of categories

A Former User

Well snort did work ,Now it crashes pfsense .So i did a reinstall of pfsense and installed snort and tryed to update now i get this snort rules: md5 signature of rules mismatch.So i guess i will go back to my d-link . >:(

shiftyjoe

onhel - Thanks for the help, changed to ac-bnfa and snort is much happier now.

cdx304 - "Well snort did work ,Now it crashes pfsense .So i did a reinstall of pfsense and installed snort and tryed to update now i get this snort rules: md5 signature of rules mismatch.So i guess i will go back to my d-link . Angry"

Not sure if it will help, but I've gotten this message. After a fifteen minute wait, I could re download the rules without an issue.

AhnHEL

Yes, I have gotten the md5 mismatch a couple of times as well during the testing of Snort 2.7.0.1_1 and 2.7.0.1_2. A second attempt to download rules always cleared up this error.

While I have this post up, I'd like to give my thanks to Sullrich for maintaining the package and Shaddow501 for his help to Sullrich in getting the problems with 2.7 resolved so quickly for all of us end-users. Great job guys.

rt_rex

@onhel:

Yes, I have gotten the md5 mismatch a couple of times as well during the testing of Snort 2.7.0.1_1 and 2.7.0.1_2. A second attempt to download rules always cleared up this error.

While I have this post up, I'd like to give my thanks to Sullrich for maintaining the package and Shaddow501 for his help to Sullrich in getting the problems with 2.7 resolved so quickly for all of us end-users. Great job guys.

There is a 2.7.0.1_3 version working ok here

A Former User

Pfsense crashes now with snort installed .

AhnHEL

Define @cdx304:

Pfsense crashes now with snort installed .

Define "crash."

Please elaborate.

Mine is running great, possibly a hardware issue?

shaddow501

Hi All

After a few days working with snort i have found that it doesnt remove the blocked IP after 60 min, maybe it is something with the configuration i am nit sure yet.

i do think that should be a line in the cron configuration that after a specific time it removes the blocked IPs, or maybe i am wrong…

Did anyone notice that problem or is it just something messed up in my system.

anyway any information where i should write this line i will appreciate.

shiftyjoe

This post (http://forum.pfsense.org/index.php/topic,5902.0.html) is talking about how to change the time it take before the ip's are removed.

Sullrich says "You can change the reset time by modifying /cf/conf/config.xml from Diagnostics -> Edit File.

Look for the cron entry that runs the command /usr/local/sbin/expiretable -t 1800 snort2c.

Change the <minute>60</minute> to whatever you like. Then go to Diagnostics -> Command Prompt and in the PHP command box issue the command:

configure_cron();"

I'ld check to make sure the cron job is schedualed.

AhnHEL

Watched a blocked IP and noticed it was removed after around 87 minutes. Performed a second test and this one went beyond 115 minutes before I gave up on babysitting the GUI so I can confirm your experiences Shaddow501. One thing I noticed while tinkering around with this is that "top" doesnt show snort2c running when an IP is blocked. I can verify that the IP is in fact blocked so I can only assume snort2c is doing its job but strange that I dont see it running when I know I've seen snort2c by running Top in the past.

shaddow501

Hi OnHel

Well i do think that the reason because snort crash (i do see strange line in my log that refer to snort exited core dump , well something like that, i do thing it isnt a very stable release, any way i am working on snort.inc file to see if by removing some items it will make snort work better… (like the SMTP check that i have added and FTP processor that i have added, so far i have removed the SMTP and will try to check it for a few days to see if it will make the release more stale.
if you would like to "play" also with the file then it is located at /usr/local/pkg/snort.inc (just use edit file in snort gui)

also i did modification in cron that will remove the blocked ip after 10 min, and i guess it does work...

shaddow501

Hi Guys

I have started to work with snort version-2.8.0.1, since I didnt like much the 2.7.0.1, i have made a new package based on the snort 2.7.0.1 but with files of the new last version i mention above.
In the terminal ssh software i just pkg_delete the old version and did pkg_add to my version.

the new version seem to work so far, but i still not have much information of how stable it is.
It also require a change in the snort.inc file.

anyone that wish to try it may contact me

trendchiller

Perhaps give scott a link if it runs fine ;-)

AhnHEL

Shaddow501, I've been studying the snort.inc file, and trust me I'm not in your league at all in understanding it, nor would I have been able to fix it the way you did previously when the preprocessors were causing Snort to crash.

But I did notice that some alerts werent properly being set off. For instance, ICMP pings to my WAN IP werent setting off a Snort Alert even though I have the same ICMP rules enabled as I did with 2.6

Then I noticed that you had the preprocessor flow enabled in the snort.inc file. According to this site http://cvs.snort.org/viewcvs.cgi/snort/doc/README.stream5?rev=1.2

The Stream5 preprocessor is a target-based TCP reassembly module
for Snort. It is intended to replace both the stream4 and flow
preprocessors, and it is capable of tracking sessions for both
TCP and UDP. With Stream5, the rule 'flow' and 'flowbits' keywords
are usable with TCP as well as UDP traffic.

Since Stream5 replaces stream4, both cannot be used simultaneously.
Remove the stream4 and flow configurations from snort.conf when the
stream5 configuration is added.

I commented out the flow preprocessor and I'm now seeing ICMP ping alerts again.

shaddow501

Hi OnHeL

Well you are right, with the last version of snort 2.8.0.1 i did disable the flow preprocessor, i did compile the 2.8.0.1 that will also support stream4udp packets so it does work with both stream5 and stream4 configuration (but will not work together, you must select if you want to use stram4 or stream5 option)

With the both versions (2.7.0.1 & 2.8.0.1) i still have a problem after some time (could be hours and could be minutes) snort exit with this message:
" (snort), uid 0: exited on signal 11 (core dumped)" I havent got any clue what could cause it and looking into web (google and such) didnt resolved much information…

I am curious if it is just me that get this error or some of you do get it as well, if someone have got any clue how to debug it and see what cause this fault i could have a bit more progress, but as for now i am kinda stuck with lack of information.

I did try snort with almost all the working methods but again i do get the message and snort stop doing what it should be doing (blocking :))

anyone?

chazers18

i have a Similar problem that some of the others are having with Snort

version of PFsense

1.2-RC2
built on Fri Aug 17 17:46:06 EDT 2007

Some of the goofy errors that i am getting with snort

Dec 19 07:54:49 SnortStartup[63790]: Ram free BEFORE starting Snort: 73M – Ram free AFTER starting Snort: 73M -- Mode ac-std -- Snort memory usage:
Dec 19 07:54:43 kernel: xl0: promiscuous mode disabled
Dec 19 07:54:32 snort[63624]: Daemon parent exiting
Dec 19 07:54:32 snort[63624]: Daemon parent exiting
Dec 19 07:54:32 snort[63638]: Daemon initialized, signaled parent pid: 63624
Dec 19 07:54:32 snort[63638]: Daemon initialized, signaled parent pid: 63624
Dec 19 07:54:32 snort[63638]: Writing PID "63638" to file "/var/run//snort_xl0.pid"
Dec 19 07:54:32 snort[63638]: Writing PID "63638" to file "/var/run//snort_xl0.pid"
Dec 19 07:54:32 snort[63638]: PID path stat checked out ok, PID path set to /var/run/
Dec 19 07:54:32 snort[63638]: PID path stat checked out ok, PID path set to /var/run/
Dec 19 07:54:32 kernel: xl0: promiscuous mode enabled
Dec 19 07:54:32 snort[63624]: Initializing daemon mode
Dec 19 07:54:32 snort[63624]: Initializing daemon mode
Dec 19 07:54:32 kernel: xl0: promiscuous mode disabled
Dec 19 07:54:32 kernel: xl0: promiscuous mode enabled

also it does not stop any thing or set off any alerts i am just useing default rules pulled in from snort. let me know what you are all thinking.

Thanks

AhnHEL

Shaddow501

http://forum.pfsense.org/index.php/topic,2624.15.html

In the above thread, PC_Arcade was having that exact problem. Personally I'm not experiencing this error at all. Sending you a PM

Chazers18:

You're running Snort on your LAN interface, should be your WAN. Go to Services/Snort/Settings, reselect WAN interface and then hit Save. Sometimes deleting any currently blocked IPs and making sure the Snort logs are cleared and then going to the Categories tab and hitting Save again will stop this error and give you a successful initialization. Read this entire thread and you'll see information on setting up Snort to use ac-bnfa mode, this is highly recommended.

chazers18

the funny thing is… that is not my lan. well atleast via the GUi i didnt select the lan i did both wans and then just one wan and that is what happpens the premicous starts and then after a while it kicks out.

this is a production device and i am gun shy on hacking the xml backup i will give it a shot and let you know what happens.

AhnHEL

For some reason, when you select WAN, Snort tries to start on another interface. Sometimes its necessary to hit Save twice on the Settings tab to make it stick. Where it says in your logs:

Dec 19 07:54:32 snort[63638]: Writing PID "63638" to file "/var/run//snort_xl0.pid"
Dec 19 07:54:32 snort[63638]: Writing PID "63638" to file "/var/run//snort_xl0.pid"

It shouldnt say snort_xl0.pid. It should say snort_(WAN interface name).pid

As of right now until the package is updated, its going to be necessary to edit /usr/local/pkg/snort.inc and commenting out the following line so Snort can work properly with certain rules.:

#Flow and stream
preprocessor flow: stats_interval 0 hash 2

Comment the above line out with a # before the word "preprocessor"

morbus

It shouldnt say snort_xl0.pid. It should say snort_(WAN interface name).pid

That is exactly what it should say (assuming xl0 is your wan interface) I guess chazers18 is using 3com nics or something that uses the xl driver

Comment the above line out with a # before the word "preprocessor"

I don't see any reason why you can't use stream5 and flow on the same snort. Snort won't normally trigger for every ICMP packet it receives unless you add a rule for that eg```
alert icmp any any -> any any (msg:"ICMP test"; sid:1000005;)