[Snort-users] network bandwidth downs when snort inoine is up

carlopmart carlopmart at ...11827...
Tue Oct 9 18:20:25 EDT 2007


Victor Julien wrote:
> carlopmart wrote:
>> Yes: norm_wscale_max 14
>>   
> This should be ok. Can you past your entire stream4 config?
> 
> It doesn't have to be a stream4inline issue though. The number of sigs,
> preprocessors, etc. can also slow things down. Especially the clamav
> preproc.
> 
> Regards,
> Victor

I think that the problem is the clamav preprocessor too, but I didn't 
hope that it was so slow ...

My config:

# Step #3: Configure preprocessors

preprocessor flow: stats_interval 0 hash 2
preprocessor stream4: disable_evasion_alerts, stream4inline, 
enforce_state drop, memcap 134217728, timeout 3600, \
                         truncate, window_size 3000, disable_ooo_alerts, 
norm_wscale_max 14
preprocessor stream4_reassemble: both, favor_new
preprocessor stickydrop: max_entries 3000, log
preprocessor stickydrop-timeouts: sfportscan 3000, clamav 3000
preprocessor stickydrop-ignorehosts: 172.17.35.0/29
preprocessor clamav: ports all !22 !443, action-drop, dbdir /var/clamav, 
dbreload-time 43200
#preprocessor http_inspect: global iis_unicode_map unicode.map 1252
#preprocessor http_inspect_server: server default profile all ports { 80 
8080 } oversize_dir_length 500
preprocessor rpc_decode: 111 32771
preprocessor bo
preprocessor ftp_telnet: global encrypted_traffic yes inspection_type 
stateful
preprocessor ftp_telnet_protocol: telnet normalize ayt_attack_thresh 200
preprocessor ftp_telnet_protocol: ftp server default def_max_param_len 
100 alt_max_param_len 200 { CWD } cmd_validity MODE < char ASBCZ > \
                 cmd_validity MDTM < [ date nnnnnnnnnnnnnn[.n[n[n]]] ] 
string > chk_str_fmt { USER PASS RNFR RNTO SITE MKD } telnet_cmds yes 
data_chan
preprocessor ftp_telnet_protocol: ftp client default max_resp_len 256 
bounce yes telnet_cmds yes
preprocessor smtp: ports { 25 } inspection_type stateful normalize cmds 
normalize_cmds { EXPN VRFY RCPT } alt_max_command_line_len 260 { MAIL } \
                 alt_max_command_line_len 300 { RCPT } 
alt_max_command_line_len 500 { HELP HELO ETRN } alt_max_command_line_len 
255 { EXPN VRFY }
preprocessor sfportscan: proto  { all } memcap { 10000000 } sense_level 
{ low }
preprocessor dcerpc: autodetect max_frag_size 3000 memcap 100000
preprocessor dns: ports { 53 } enable_rdata_overflow
preprocessor perfmonitor: time 300 file /tmp/snort.stats pktcnt 10000


> 
> 
>> Will Metcalf wrote:
>>   
>>> do you have window normalization enabled in your stream4inline config?
>>>
>>> On 10/9/07, carlopmart <carlopmart at ...11827...> wrote:
>>>     
>>>> hi all,
>>>>
>>>>   I have configured a snort inline on my home network. (i am using
>>>> clamav preprocessor on it). First problem is bandwidth: downs from 310
>>>> kb to 166 kb (previosly exists some fluctuations) ... Is this normal?
>>>> Can I set up some kernel param to increase this bandwidth?? I am using
>>>> rhel5 and snor-inline 2.6.1.5
>>>>
>>>> Many thanks.
>>>>
>>>> --
>>>> CL Martinez
>>>> carlopmart {at} gmail {d0t} com
>>>>
>>>> -------------------------------------------------------------------------
>>>> This SF.net email is sponsored by: Splunk Inc.
>>>> Still grepping through log files to find problems?  Stop.
>>>> Now Search log events and configuration files using AJAX and a browser.
>>>> Download your FREE copy of Splunk now >> http://get.splunk.com/
>>>> _______________________________________________
>>>> Snort-users mailing list
>>>> Snort-users at lists.sourceforge.net
>>>> Go to this URL to change user options or unsubscribe:
>>>> https://lists.sourceforge.net/lists/listinfo/snort-users
>>>> Snort-users list archive:
>>>> http://www.geocrawler.com/redir-sf.php3?list=snort-users
>>>>
>>>>       
>>
>>   
> 
> 
> -------------------------------------------------------------------------
> This SF.net email is sponsored by: Splunk Inc.
> Still grepping through log files to find problems?  Stop.
> Now Search log events and configuration files using AJAX and a browser.
> Download your FREE copy of Splunk now >> http://get.splunk.com/
> _______________________________________________
> Snort-users mailing list
> Snort-users at lists.sourceforge.net
> Go to this URL to change user options or unsubscribe:
> https://lists.sourceforge.net/lists/listinfo/snort-users
> Snort-users list archive:
> http://www.geocrawler.com/redir-sf.php3?list=snort-users
> 


-- 
CL Martinez
carlopmart {at} gmail {d0t} com




More information about the Snort-users mailing list