snort 笔记1 ----- 3种模式简介
snort笔记：2011-04-18
链接snort中文手册，比较老的一个：
http://man.chinaunix.net/network/snort/Snortman.htm。
一 基本操作：
1 配置文件位置：/etc/snort
2 运行：./snort 需要root权限 【这是cd到/usr/sbin目录后的操作，要是在别的目录下，可以通过制定全路径】
【补充：linux下执行程序，如果在当前目录下的执行文件，则需要加 ./程序名 ，如果是全路径，则不需要加这个点，比如
这里全路径指向snort： /usr/sbin/snort -vde 等， ./表示相对当前目录】
3 开机自启动关闭：http://blog.csdn.net/jo_say/archive/2011/03/08/6232952.aspx
如snort的2，3，4，5级默认开启，通过chkconfig –-level 2345 snort off.就可将其关闭。（chkconfig操作见：http://blog.csdn.net/jo_say/archive/2011/04/18/6330466.aspx
（网上介绍：on和off开关，系统默认只对运行级3，4，5有效，但是reset可以对所有运行级有效,但是我刚才好像把2也off了，也ok了）
二：三种模式：
1 嗅探 (snort从网络上读出数据包并将其显示在控制台上）
2 数据包记录器（将数据包记录在硬盘上）
3 NIDS（最复杂，可配置，允许snort匹配用户自定义的数据集，并根据检测结果执行一定的动作）
三：实际操作：
- 嗅探模式：
1. ./snort -v
启动snort后会显示：
【1】模式
【2】初始化输出插件
【3】显示snort版本信息和版权信息
【4】显示数据包到控制台
****************************************************************************************************************************
root@helloworld:/# ./usr/sbin/snort -v
Running in packet dump mode 数据包转储模式
--== Initializing Snort ==--
Initializing Output Plugins!
***
*** interface device lookup found: eth0
***
Initializing Network Interface eth0
Decoding Ethernet on interface eth0
--== Initialization Complete ==--
,,_ -*> Snort! <*-
o" )~ Version 2.8.5.2 (Build 121)
'''' By Martin Roesch & The Snort Team: http://www.snort.org/snort/snort-team
Copyright (C) 1998-2009 Sourcefire, Inc., et al.
Using PCRE version: 8.02 2010-03-19
Not Using PCAP_FRAMES // 为什么会提示？见 http://blog.csdn.net/jo_say/archive/2011/04/18/6331819.aspx]
//下面这个数据包是外部主机发往局域网其它主机的数据包
04/18-16:32:10.267583 118.239.104.219:1119 -> 172.26.75.118:10118
UDP TTL:52 TOS:0x0 ID:5308 IpLen:20 DgmLen:68
Len: 40
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
// 下面这个数据包是本机发往csdn的80端口的数据包
04/18-16:32:10.609564 172.26.75.115:39112 -> 211.100.26.77:80
TCP TTL:64 TOS:0x0 ID:12047 IpLen:20 DgmLen:40 DF
***A***F Seq: 0xD2B01068 Ack: 0xCA0FABA Win: 0x8E TcpLen: 20
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
04/18-16:32:10.609645 172.26.75.115:39068 -> 211.100.26.77:80
TCP TTL:64 TOS:0x0 ID:61231 IpLen:20 DgmLen:40 DF
***A***F Seq: 0x9969190B Ack: 0x8879377 Win: 0xD0 TcpLen: 20
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
**********************************************************************************
2 默认只显示包头信息，如果需要显示数据包应用层的内容，需要加上-d 参数：
结果如下所示，摘取其二：
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
04/18-18:26:52.610961 172.26.75.115:34474 -> 211.100.26.77:80
TCP TTL:64 TOS:0x0 ID:2855 IpLen:20 DgmLen:536 DF
***AP*** Seq: 0x296C9AB4 Ack: 0xA891280A Win: 0x5C TcpLen: 20
32 61 35 31 33 63 64 62 32 37 63 31 39 39 30 66 2a513cdb27c1990f
37 33 63 65 61 37 32 34 30 61 3B 20 5F 5F 6D 65 73cea7240a; __me
73 73 61 67 65 5F 73 79 73 5F 6D 73 67 5F 69 64 ssage_sys_msg_id
3D 39 35 36 3B 20 41 53 50 2E 4E 45 54 5F 53 65 =956; ASP.NET_Se
73 73 69 6F 6E 49 64 3D 79 78 77 78 30 72 79 6D ssionId=yxwx0rym
74 73 75 6E 35 30 34 35 30 72 61 75 6E 30 6D 69 tsun50450raun0mi
3B 20 54 65 73 74 43 6F 6F 6B 69 65 3D 34 2F 31 ; TestCookie=4/1
38 2F 32 30 31 31 20 35 3A 34 37 3A 34 39 20 50 8/2011 5:47:49 P
4D 3B 20 5F 5F 6D 65 73 73 61 67 65 5F 67 75 5F M; __message_gu_
6D 73 67 5F 69 64 3D 30 3B 20 5F 5F 6D 65 73 73 msg_id=0; __mess
61 67 65 5F 63 6E 65 6C 5F 6D 73 67 5F 69 64 3D age_cnel_msg_id=
30 3B 20 5F 5F 6D 65 73 73 61 67 65 5F 69 6E 5F 0; __message_in_
73 63 68 6F 6F 6C 3D 30 3B 20 43 53 44 4E 42 6C school=0; CSDNBl
6F 67 42 6C 6F 67 49 64 3D 31 37 36 30 36 32 3B ogBlogId=176062;
20 75 63 68 6F 6D 65 5F 73 79 6E 66 72 69 65 6E uchome_synfrien
64 3D 31 3B 20 2E 44 6F 74 74 65 78 74 43 6F 6F d=1; .DottextCoo
6B 69 65 3D 32 35 44 41 32 43 37 33 41 46 44 37 kie=25DA2C73AFD7
35 30 31 31 32 43 39 46 46 30 38 32 36 46 41 30 50112C9FF0826FA0
39 30 32 38 36 36 30 36 35 30 30 44 37 33 46 32 90286606500D73F2
44 31 45 44 42 42 44 37 35 35 39 44 32 42 43 34 D1EDBBD7559D2BC4
33 42 37 46 44 34 30 46 37 35 43 38 45 32 41 30 3B7FD40F75C8E2A0
32 38 38 44 30 43 33 45 36 34 34 45 38 46 35 36 288D0C3E644E8F56
32 31 43 33 35 43 31 31 38 42 34 34 30 42 31 46 21C35C118B440B1F
44 37 31 30 44 37 38 34 43 46 45 31 35 34 30 33 D710D784CFE15403
44 46 35 37 41 42 44 43 36 42 34 33 41 44 31 31 DF57ABDC6B43AD11
32 46 33 35 43 36 39 45 43 33 32 44 44 41 44 34 2F35C69EC32DDAD4
30 41 39 38 38 45 45 31 37 43 38 46 30 36 46 34 0A988EE17C8F06F4
42 42 34 31 30 46 41 31 44 30 31 46 34 44 46 37 BB410FA1D01F4DF7
37 37 32 37 44 44 42 33 41 35 36 33 45 42 41 42 7727DDB3A563EBAB
41 37 37 44 38 34 32 37 38 41 45 44 46 42 37 46 A77D84278AEDFB7F
42 42 42 30 42 46 42 35 39 38 32 30 0D 0A 0D 0A BBB0BFB59820....
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
04/18-18:26:52.738985 211.100.26.77:80 -> 172.26.75.115:34474
TCP TTL:47 TOS:0x0 ID:42094 IpLen:20 DgmLen:269 DF
***AP*** Seq: 0xA891280A Ack: 0x296CD8AC Win: 0x56 TcpLen: 20
48 54 54 50 2F 31 2E 31 20 32 30 30 20 4F 4B 0D HTTP/1.1 200 OK.
0A 53 65 72 76 65 72 3A 20 6E 67 69 6E 78 2F 30 .Server: nginx/0
2E 37 2E 36 38 0D 0A 44 61 74 65 3A 20 4D 6F 6E .7.68..Date: Mon
2C 20 31 38 20 41 70 72 20 32 30 31 31 20 31 30 , 18 Apr 2011 10
3A 32 36 3A 35 30 20 47 4D 54 0D 0A 43 6F 6E 6E :26:50 GMT..Conn
65 63 74 69 6F 6E 3A 20 6B 65 65 70 2D 61 6C 69 ection: keep-ali
76 65 0D 0A 58 2D 55 41 2D 43 6F 6D 70 61 74 69 ve..X-UA-Compati
62 6C 65 3A 20 49 45 3D 45 6D 75 6C 61 74 65 49 ble: IE=EmulateI
45 37 0D 0A 58 2D 50 6F 77 65 72 65 64 2D 42 79 E7..X-Powered-By
3A 20 41 53 50 2E 4E 45 54 0D 0A 58 2D 41 73 70 : ASP.NET..X-Asp
4E 65 74 2D 56 65 72 73 69 6F 6E 3A 20 32 2E 30 Net-Version: 2.0
2E 35 30 37 32 37 0D 0A 43 61 63 68 65 2D 43 6F .50727..Cache-Co
6E 74 72 6F 6C 3A 20 70 72 69 76 61 74 65 0D 0A ntrol: private..
43 6F 6E 74 65 6E 74 2D 4C 65 6E 67 74 68 3A 20 Content-Length:
30 0D 0A 0D 0A 0....
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
- 数据包记录器模式
为了只对本地网络进行日志，需要加上参数-h。如：
./snort -vde -l ./log -h 192.168.1.0/24
这个命令告诉snort把进入C类网络192.168.1的所有包的数据链路、TCP/IP以及应用层的数据记录到目录./log中。
二进制方式：
./snort -l ./log -b
[ 从manuel中看：使用二进制方式和普通方式应该在log文件命名方面有区别的，但我自己测试后，却没有得到效果，产生的log文件名都是一种类型，eg：
*************************************************
root@helloworld:/usr/sbin# ls ./log
snort.log.1303126222 snort.log.1303128331 snort.log.1303128351 snort.log.1303129241
*******************************
2 读出写的log文件内容：
【二进制文件是以tcpdump程序使用的格式写入的，可以使用tcpdump和ethereal读出，当然也可以使用snort读出，使用-r参数：
root@helloworld:/usr/sbin# ./snort -v -r ./log/snort.log.1303126222
将显示在嗅探模式下一样的数据到控制台中。
（不知到为什么，我上面获得的日志都是二进制的，难道那个地方我设置错了？？而且都可通过snort -r读出】
如果只想读出icmp包，则需在最后加上一个icmp参数：
./snort -v -r ./log/snort.log.1303126222 icmp
- 网络入侵检测模式（NIDS）
这才是snort的本质工作。
命令：-c 指定规则集文件位置
./snort -v -l ./log -c /etc/snort/snort.conf
下面给出整个运行结果，以做分析：
*******************************************************************************************
Running in IDS mode 【显示了当前模式】
--== Initializing Snort ==--
Initializing Output Plugins!
Initializing Preprocessors!
Initializing Plug-ins!
Parsing Rules file "/etc/snort/snort.conf"
PortVar 'HTTP_PORTS' defined : [ 80 ]
PortVar 'SHELLCODE_PORTS' defined : [ 0:79 81:65535 ]
PortVar 'ORACLE_PORTS' defined : [ 1521 ]
PortVar 'FTP_PORTS' defined : [ 21 ]
Tagged Packet Limit: 256
Loading dynamic engine /usr/lib/snort_dynamicengine/libsf_engine.so... done
Loading all dynamic preprocessor libs from /usr/lib/snort_dynamicpreprocessor/...
Loading dynamic preprocessor library /usr/lib/snort_dynamicpreprocessor//libsf_smtp_preproc.so... done
Loading dynamic preprocessor library /usr/lib/snort_dynamicpreprocessor//libsf_ftptelnet_preproc.so... done
Loading dynamic preprocessor library /usr/lib/snort_dynamicpreprocessor//libsf_dce2_preproc.so... done
Loading dynamic preprocessor library /usr/lib/snort_dynamicpreprocessor//libsf_dcerpc_preproc.so... done
Loading dynamic preprocessor library /usr/lib/snort_dynamicpreprocessor//libsf_ssl_preproc.so... done
Loading dynamic preprocessor library /usr/lib/snort_dynamicpreprocessor//libsf_dns_preproc.so... done
Loading dynamic preprocessor library /usr/lib/snort_dynamicpreprocessor//lib_sfdynamic_preprocessor_example.so... done
Loading dynamic preprocessor library /usr/lib/snort_dynamicpreprocessor//libsf_ssh_preproc.so... done
Finished Loading all dynamic preprocessor libs from /usr/lib/snort_dynamicpreprocessor/
Log directory = ./log
Frag3 global config:
Max frags: 65536
Fragment memory cap: 4194304 bytes
Frag3 engine config:
Target-based policy: FIRST
Fragment timeout: 60 seconds
Fragment min_ttl: 1
Fragment Problems: 1
Overlap Limit: 10
Min fragment Length: 0
Stream5 global config:
Track TCP sessions: ACTIVE
Max TCP sessions: 8192
Memcap (for reassembly packet storage): 8388608
Track UDP sessions: INACTIVE
Track ICMP sessions: INACTIVE
Log info if session memory consumption exceeds 1048576
Stream5 TCP Policy config:
Reassembly Policy: FIRST
Timeout: 30 seconds
Min ttl: 1
Maximum number of bytes to queue per session: 1048576
Maximum number of segs to queue per session: 2621
Reassembly Ports:
21 client (Footprint)
23 client (Footprint)
25 client (Footprint)
42 client (Footprint)
53 client (Footprint)
80 client (Footprint)
110 client (Footprint)
111 client (Footprint)
135 client (Footprint)
136 client (Footprint)
137 client (Footprint)
139 client (Footprint)
143 client (Footprint)
445 client (Footprint)
513 client (Footprint)
514 client (Footprint)
1433 client (Footprint)
1521 client (Footprint)
2401 client (Footprint)
3306 client (Footprint)
HttpInspect Config:
GLOBAL CONFIG
Max Pipeline Requests: 0
Inspection Type: STATELESS
Detect Proxy Usage: NO
IIS Unicode Map Filename: /etc/snort/unicode.map
IIS Unicode Map Codepage: 1252
DEFAULT SERVER CONFIG:
Server profile: All
Ports: 80 8080 8180
Server Flow Depth: 300
Client Flow Depth: 300
Max Chunk Length: 500000
Max Header Field Length: 0
Max Number Header Fields: 0
Inspect Pipeline Requests: YES
URI Discovery Strict Mode: NO
Allow Proxy Usage: NO
Disable Alerting: NO
Oversize Dir Length: 500
Only inspect URI: NO
Normalize HTTP Headers: NO
Normalize HTTP Cookies: NO
Ascii: YES alert: NO
Double Decoding: YES alert: YES
%U Encoding: YES alert: YES
Bare Byte: YES alert: YES
Base36: OFF
UTF 8: OFF
IIS Unicode: YES alert: YES
Multiple Slash: YES alert: NO
IIS Backslash: YES alert: NO
Directory Traversal: YES alert: NO
Web Root Traversal: YES alert: YES
Apache WhiteSpace: YES alert: NO
IIS Delimiter: YES alert: NO
IIS Unicode Map: GLOBAL IIS UNICODE MAP CONFIG
Non-RFC Compliant Characters: NONE
Whitespace Characters: 0x09 0x0b 0x0c 0x0d
rpc_decode arguments:
Ports to decode RPC on: 111 32771
alert_fragments: INACTIVE
alert_large_fragments: ACTIVE
alert_incomplete: ACTIVE
alert_multiple_requests: ACTIVE
Portscan Detection Config:
Detect Protocols: TCP UDP ICMP IP
Detect Scan Type: portscan portsweep decoy_portscan distributed_portscan
Sensitivity Level: Low
Memcap (in bytes): 10000000
Number of Nodes: 36900
FTPTelnet Config:
GLOBAL CONFIG
Inspection Type: stateful
Check for Encrypted Traffic: YES alert: YES
Continue to check encrypted data: NO
TELNET CONFIG:
Ports: 23
Are You There Threshold: 200
Normalize: YES
Detect Anomalies: NO
FTP CONFIG:
FTP Server: default
Ports: 21
Check for Telnet Cmds: YES alert: YES
Ignore Telnet Cmd Operations: OFF
Identify open data channels: YES
FTP Client: default
Check for Bounce Attacks: YES alert: YES
Check for Telnet Cmds: YES alert: YES
Ignore Telnet Cmd Operations: OFF
Max Response Length: 256
SMTP Config:
Ports: 25 587 691
Inspection Type: Stateful
Normalize: EXPN RCPT VRFY
Ignore Data: No
Ignore TLS Data: No
Ignore SMTP Alerts: No
Max Command Line Length: Unlimited
Max Specific Command Line Length:
ETRN:500 EXPN:255 HELO:500 HELP:500 MAIL:260
RCPT:300 VRFY:255
Max Header Line Length: Unlimited
Max Response Line Length: Unlimited
X-Link2State Alert: Yes
Drop on X-Link2State Alert: No
Alert on commands: None
SSH config:
Autodetection: DISABLED
Challenge-Response Overflow Alert: ENABLED
SSH1 CRC32 Alert: ENABLED
Server Version String Overflow Alert: ENABLED
Protocol Mismatch Alert: ENABLED
Bad Message Direction Alert: DISABLED
Bad Payload Size Alert: DISABLED
Unrecognized Version Alert: DISABLED
Max Encrypted Packets: 20
Max Server Version String Length: 80 (Default)
MaxClientBytes: 19600 (Default)
Ports:
22
DCE/RPC 2 Preprocessor Configuration
Global Configuration
DCE/RPC Defragmentation: Enabled
Memcap: 102400 KB
Events: none
Server Default Configuration
Policy: WinXP
Detect ports
SMB: 139 445
TCP: 135
UDP: 135
RPC over HTTP server: 593
RPC over HTTP proxy: None
Autodetect ports
SMB: None
TCP: 1025-65535
UDP: 1025-65535
RPC over HTTP server: 1025-65535
RPC over HTTP proxy: None
Maximum SMB command chaining: 3 commands
DNS config:
DNS Client rdata txt Overflow Alert: ACTIVE
Obsolete DNS RR Types Alert: INACTIVE
Experimental DNS RR Types Alert: INACTIVE
Ports: 53
SSLPP config:
Encrypted packets: not inspected
Ports:
443 465 563 636 989
992 993 994 995
Server side data is trusted
+++++++++++++++++++++++++++++++++++++++++++++++++++
Initializing rule chains...
Warning: /etc/snort/rules/dos.rules(42) => threshold (in rule) is deprecated; use detection_filter instead.
3382 Snort rules read
3382 detection rules
0 decoder rules
0 preprocessor rules
3382 Option Chains linked into 282 Chain Headers
0 Dynamic rules
+++++++++++++++++++++++++++++++++++++++++++++++++++
+-------------------[Rule Port Counts]---------------------------------------
| tcp udp icmp ip
| src 121 19 0 0
| dst 2922 130 0 0
| any 115 53 56 27
| nc 31 10 15 20
| s+d 12 6 0 0
+----------------------------------------------------------------------------
+-----------------------[detection-filter-config]------------------------------
| memory-cap : 1048576 bytes
+-----------------------[detection-filter-rules]-------------------------------
| none
-------------------------------------------------------------------------------
+-----------------------[rate-filter-config]-----------------------------------
| memory-cap : 1048576 bytes
+-----------------------[rate-filter-rules]------------------------------------
| none
-------------------------------------------------------------------------------
+-----------------------[event-filter-config]----------------------------------
| memory-cap : 1048576 bytes
+-----------------------[event-filter-global]----------------------------------
| none
+-----------------------[event-filter-local]-----------------------------------
| gen-id=1 sig-id=2494 type=Both tracking=dst count=20 seconds=60
| gen-id=1 sig-id=100000162 type=Both tracking=src count=100 seconds=60
| gen-id=1 sig-id=100000159 type=Both tracking=src count=100 seconds=60
| gen-id=1 sig-id=2496 type=Both tracking=dst count=20 seconds=60
| gen-id=1 sig-id=100000310 type=Limit tracking=src count=1 seconds=360
| gen-id=1 sig-id=3273 type=Threshold tracking=src count=5 seconds=2
| gen-id=1 sig-id=100000923 type=Threshold tracking=dst count=200 seconds=60
| gen-id=1 sig-id=100000311 type=Limit tracking=src count=1 seconds=360
| gen-id=1 sig-id=2275 type=Threshold tracking=dst count=5 seconds=60
| gen-id=1 sig-id=100000161 type=Both tracking=dst count=100 seconds=60
| gen-id=1 sig-id=100000158 type=Both tracking=src count=100 seconds=60
| gen-id=1 sig-id=2923 type=Threshold tracking=dst count=10 seconds=60
| gen-id=1 sig-id=100000163 type=Both tracking=src count=100 seconds=60
| gen-id=1 sig-id=100000160 type=Both tracking=src count=300 seconds=60
| gen-id=1 sig-id=2523 type=Both tracking=dst count=10 seconds=10
| gen-id=1 sig-id=100000312 type=Limit tracking=src count=1 seconds=360
| gen-id=1 sig-id=2924 type=Threshold tracking=dst count=10 seconds=60
| gen-id=1 sig-id=2495 type=Both tracking=dst count=20 seconds=60
| gen-id=1 sig-id=3152 type=Threshold tracking=src count=5 seconds=2
+-----------------------[suppression]------------------------------------------
| none
-------------------------------------------------------------------------------
Rule application order: activation->dynamic->pass->drop->alert->log
Verifying Preprocessor Configurations!
Warning: flowbits key 'smb.tree.create.llsrpc' is set but not ever checked.
Warning: flowbits key 'realplayer.playlist' is checked but not ever set.
Warning: flowbits key 'community_uri.size.1050' is set but not ever checked.
Warning: flowbits key 'ms_sql_seen_dns' is checked but not ever set.
37 out of 512 flowbits in use.
***
*** interface device lookup found: eth0
***
Initializing Network Interface eth0
Decoding Ethernet on interface eth0
Node unique name is: 172.26.75.115
database: compiled support for (mysql)
database: configured to use mysql
database: schema version = 107
database: host = localhost
database: user = snort
database: database name = snort
database: sensor name = 172.26.75.115
database: sensor id = 1
database: data encoding = hex
database: detail level = full
database: ignore_bpf = no
database: using the "log" facility
[ Port Based Pattern Matching Memory ]
+-[AC-BNFA Search Info Summary]------------------------------
| Instances : 241
| Patterns : 22049
| Pattern Chars : 207222
| Num States : 137800
| Num Match States : 18343
| Memory : 3.51Mbytes
| Patterns : 0.70M
| Match Lists : 0.96M
| Transitions : 1.79M
+-------------------------------------------------
--== Initialization Complete ==--
,,_ -*> Snort! <*-
o" )~ Version 2.8.5.2 (Build 121)
'''' By Martin Roesch & The Snort Team: http://www.snort.org/snort/snort-team
Copyright (C) 1998-2009 Sourcefire, Inc., et al.
Using PCRE version: 8.02 2010-03-19
Rules Engine: SF_SNORT_DETECTION_ENGINE Version 1.11
Preprocessor Object: SF_SSH Version 1.1
Preprocessor Object: SF_Dynamic_Example_Preprocessor Version 1.0
Preprocessor Object: SF_DNS Version 1.1
Preprocessor Object: SF_SSLPP Version 1.1
Preprocessor Object: SF_DCERPC Version 1.1
Preprocessor Object: SF_DCERPC2 Version 1.0
Preprocessor Object: SF_FTPTELNET Version 1.2
Preprocessor Object: SF_SMTP Version 1.1
Using PCAP_FRAMES = max
04/18-20:56:55.568511 183.62.125.17:80 -> 172.26.75.115:47155
TCP TTL:50 TOS:0x0 ID:32178 IpLen:20 DgmLen:339 DF
***AP*** Seq: 0x8EE60060 Ack: 0xFEFE1836 Win: 0xB3 TcpLen: 32
TCP Options (3) => NOP NOP TS: 113936275 10677776
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
04/18-20:56:55.568535 172.26.75.115:47155 -> 183.62.125.17:80
TCP TTL:64 TOS:0x0 ID:65460 IpLen:20 DgmLen:52 DF
***A**** Seq: 0xFEFE1836 Ack: 0x8EE6017F Win: 0x6C TcpLen: 32
TCP Options (3) => NOP NOP TS: 10680277 113936275
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
04/18-20:56:55.568541 183.62.125.17:80 -> 172.26.75.115:47155
TCP TTL:50 TOS:0x0 ID:32179 IpLen:20 DgmLen:52 DF
***A***F Seq: 0x8EE6017F Ack: 0xFEFE1836 Win: 0xB3 TcpLen: 32
TCP Options (3) => NOP NOP TS: 113936275 10677776
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
04/18-20:56:55.568704 172.26.75.115:47155 -> 183.62.125.17:80
TCP TTL:64 TOS:0x0 ID:65461 IpLen:20 DgmLen:52 DF
***A***F Seq: 0xFEFE1836 Ack: 0x8EE60180 Win: 0x6C TcpLen: 32
TCP Options (3) => NOP NOP TS: 10680277 113936275
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
04/18-20:56:55.583144 183.62.125.17:80 -> 172.26.75.115:47155
TCP TTL:50 TOS:0x0 ID:32180 IpLen:20 DgmLen:52 DF
***A**** Seq: 0x8EE60180 Ack: 0xFEFE1837 Win: 0xB3 TcpLen: 32
TCP Options (3) => NOP NOP TS: 113936278 10680277
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
04/18-20:56:55.625244 172.26.75.115:47156 -> 183.62.125.17:80
TCP TTL:64 TOS:0x0 ID:3078 IpLen:20 DgmLen:60 DF
******S* Seq: 0x872FBE2 Ack: 0x0 Win: 0x16D0 TcpLen: 40
TCP Options (5) => MSS: 1460 SackOK TS: 10680292 0 NOP WS: 6
=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+
04/18-20:56:55.639822 183.62.125.17:80 -> 172.26.75.115:47156
TCP TTL:50 TOS:0x0 ID:0 IpLen:20 DgmLen:60 DF
***A**S* Seq: 0x8F5BBE8D Ack: 0x872FBE3 Win: 0x1650 TcpLen: 40
TCP Options (5) => MSS: 1440 SackOK TS: 113932525 10680292 NOP WS: 6
*** Caught Int-Signal
Run time prior to being shutdown was 1.310378 seconds
database: Closing connection to database "snort"
===============================================================================
Packet Wire Totals:
Received: 11
Analyzed: 11 (100.000%)
Dropped: 0 (0.000%)
Outstanding: 0 (0.000%)
===============================================================================
Breakdown by protocol (includes rebuilt packets):
ETH: 11 (100.000%)
ETHdisc: 0 (0.000%)
VLAN: 0 (0.000%)
IPV6: 0 (0.000%)
IP6 EXT: 0 (0.000%)
IP6opts: 0 (0.000%)
IP6disc: 0 (0.000%)
IP4: 11 (100.000%)
IP4disc: 0 (0.000%)
TCP 6: 0 (0.000%)
UDP 6: 0 (0.000%)
ICMP6: 0 (0.000%)
ICMP-IP: 0 (0.000%)
TCP: 11 (100.000%)
UDP: 0 (0.000%)
ICMP: 0 (0.000%)
TCPdisc: 0 (0.000%)
UDPdisc: 0 (0.000%)
ICMPdis: 0 (0.000%)
FRAG: 0 (0.000%)
FRAG 6: 0 (0.000%)
ARP: 0 (0.000%)
EAPOL: 0 (0.000%)
ETHLOOP: 0 (0.000%)
IPX: 0 (0.000%)
OTHER: 0 (0.000%)
DISCARD: 0 (0.000%)
InvChkSum: 6 (54.545%)
S5 G 1: 0 (0.000%)
S5 G 2: 0 (0.000%)
Total: 11
===============================================================================
Action Stats:
ALERTS: 0
LOGGED: 0
PASSED: 0
===============================================================================
Frag3 statistics:
Total Fragments: 0
Frags Reassembled: 0
Discards: 0
Memory Faults: 0
Timeouts: 0
Overlaps: 0
Anomalies: 0
Alerts: 0
Drops: 0
FragTrackers Added: 0
FragTrackers Dumped: 0
FragTrackers Auto Freed: 0
Frag Nodes Inserted: 0
Frag Nodes Deleted: 0
===============================================================================
Stream5 statistics:
Total sessions: 2
TCP sessions: 2
UDP sessions: 0
ICMP sessions: 0
TCP Prunes: 0
UDP Prunes: 0
ICMP Prunes: 0
TCP StreamTrackers Created: 2
TCP StreamTrackers Deleted: 2
TCP Timeouts: 0
TCP Overlaps: 0
TCP Segments Queued: 0
TCP Segments Released: 0
TCP Rebuilt Packets: 0
TCP Segments Used: 0
TCP Discards: 1
UDP Sessions Created: 0
UDP Sessions Deleted: 0
UDP Timeouts: 0
UDP Discards: 0
Events: 0
Internal Events: 0
TCP Port Filter
Dropped: 0
Inspected: 0
Tracked: 5
UDP Port Filter
Dropped: 0
Inspected: 0
Tracked: 0
===============================================================================
HTTP Inspect - encodings (Note: stream-reassembled packets included):
POST methods: 0
GET methods: 0
Headers extracted: 0
Header Cookies extracted: 0
Post parameters extracted: 0
Unicode: 0
Double unicode: 0
Non-ASCII representable: 0
Base 36: 0
Directory traversals: 0
Extra slashes ("//"): 0
Self-referencing paths ("./"): 0
Total packets processed: 1
===============================================================================
dcerpc2 Preprocessor Statistics
Total sessions: 0
===============================================================================
===============================================================================
Snort exiting
在NIDS模式下，有很多的方式来配置snort的输出。在默认情况下，snort以ASCII格式记录日志，使用full报警机制。如果使用full报警机制，snort会在包头之后打印报警消息。如果你不需
要日志包，可以使用-N选项。
snort有6种报警机制：full、fast、socket、syslog、smb(winpopup)和none。其中有4个可以在命令行状态下使用-A选项设置。这4个是：
-A fast：报警信息包括：一个时间戳(timestamp)、报警消息、源/目的IP地址和端口。-A full：是默认的报警模式。
-A unsock：把报警发送到一个UNIX套接字，需要有一个程序进行监听，这样可以实现实时报警。
-A none：关闭报警机制。
使用-s选项可以使snort把报警消息发送到syslog，默认的设备是LOG_AUTHPRIV和LOG_ALERT。可以修改snort.conf文件修改其配置。
snort还可以使用SMB报警机制，通过SAMBA把报警消息发送到Windows主机。为了使用这个报警机制，在运行./configure脚本时，必须使用--enable-smbalerts选项。
下面是一些输出配置的例子：
使用默认的日志方式(以解码的ASCII格式)并且把报警发给syslog：
./snort -c snort.conf -l ./log -s -h 192.168.1.0/24
使用二进制日志格式和SMB报警机制：
./snort -c snort.conf -b -M WORKSTATIONS
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