使用Firepower威胁防御捕获和Packet Tracer
目录
简介
本文档介绍如何使用Firepower威胁防御(FTD)捕获和Packet Tracer实用程序。
先决条件
要求
本文档没有任何特定的要求。
使用的组件
本文档中的信息基于以下软件版本：
- 运行FTD软件6.1.0的ASA5515-X
- 运行FTD软件6.2.2的FPR4110
- 运行Firepower管理中心(FMC)软件6.2.2的FS4000
本文档中的信息都是基于特定实验室环境中的设备编写的。本文档中使用的所有设备最初均采用原始（默认）配置。如果您的网络处于活动状态，请确保您了解所有命令的潜在影响。
背景信息
FTD数据包处理
FTD数据包处理可视化如下：
- 数据包进入入口接口，由LINA引擎处理。
- 如果策略要求数据包由Snort引擎进行检查。
- Snort引擎返回数据包的判定。
- LINA 引擎根据 Snort 的判定丢弃或转发数据包.
基于该体系结构，可以在以下位置获取FTD捕获：
配置
网络图
使用Snort引擎捕获
先决条件
在FTD上应用访问控制策略(ACP)，允许互联网控制消息协议(ICMP)流量通过。该策略还应用了入侵策略：
要求
- 在FTD CLISH模式下启用捕获，无需过滤器。
- 通过FTD ping并检查捕获的输出。
解决方案
步骤1.登录到FTD控制台或SSH以访问br1接口，并在FTD CLISH模式下启用捕获功能，而不使用过滤器。
> capture-traffic Please choose domain to capture traffic from: 0 - br1 1 - Router Selection? 1 Please specify tcpdump options desired. (or enter '?' for a list of supported options) Options:
在FTD 6.0.x上，命令为：
> system support capture-traffic
步骤2.通过FTD执行ping操作并检查捕获的输出。
> capture-traffic Please choose domain to capture traffic from: 0 - br1 1 - Router Selection? 1 Please specify tcpdump options desired. (or enter '?' for a list of supported options) Options: 12:52:34.749945 IP olab-vl603-gw.cisco.com > olab-vl647-gw.cisco.com: ICMP echo request, id 0, seq 1, length 80 12:52:34.749945 IP olab-vl647-gw.cisco.com > olab-vl603-gw.cisco.com: ICMP echo reply, id 0, seq 1, length 80 12:52:34.759955 IP olab-vl603-gw.cisco.com > olab-vl647-gw.cisco.com: ICMP echo request, id 0, seq 2, length 80 12:52:34.759955 IP olab-vl647-gw.cisco.com > olab-vl603-gw.cisco.com: ICMP echo reply, id 0, seq 2, length 80 12:52:34.759955 IP olab-vl603-gw.cisco.com > olab-vl647-gw.cisco.com: ICMP echo request, id 0, seq 3, length 80 12:52:34.759955 IP olab-vl647-gw.cisco.com > olab-vl603-gw.cisco.com: ICMP echo reply, id 0, seq 3, length 80 12:52:34.759955 IP olab-vl603-gw.cisco.com > olab-vl647-gw.cisco.com: ICMP echo request, id 0, seq 4, length 80 12:52:34.759955 IP olab-vl647-gw.cisco.com > olab-vl603-gw.cisco.com: ICMP echo reply, id 0, seq 4, length 80 ^C <- to exit press CTRL + C
使用Snort引擎捕获
要求
- 在FTD CLISH模式下使用IP 192.168.101.1过滤器启用捕获。
- 通过FTD Ping并检查捕获的输出。
解决方案
步骤1.在FTD CLISH模式下使用IP 192.168.101.1的过滤器启用捕获。
> capture-traffic Please choose domain to capture traffic from: 0 - br1 1 - Router Selection? 1 Please specify tcpdump options desired. (or enter '?' for a list of supported options) Options: host 192.168.101.1
步骤2.Ping FTD并检查捕获的输出：
13:28:36.079982 IP olab-vl647-gw.cisco.com > olab-vl603-gw.cisco.com: ICMP echo reply, id 3, seq 0, length 80 13:28:36.079982 IP olab-vl647-gw.cisco.com > olab-vl603-gw.cisco.com: ICMP echo reply, id 3, seq 1, length 80 13:28:36.079982 IP olab-vl647-gw.cisco.com > olab-vl603-gw.cisco.com: ICMP echo reply, id 3, seq 2, length 80 13:28:36.079982 IP olab-vl647-gw.cisco.com > olab-vl603-gw.cisco.com: ICMP echo reply, id 3, seq 3, length 80 13:28:36.079982 IP olab-vl647-gw.cisco.com > olab-vl603-gw.cisco.com: ICMP echo reply, id 3, seq 4, length 80
可以使用-n选项查看数字格式的主机和端口号。例如，早期的捕获显示为：
> capture-traffic Please choose domain to capture traffic from: 0 - br1 1 - Router Selection? 1 Please specify tcpdump options desired. (or enter '?' for a list of supported options) Options: -n host 192.168.101.1 13:29:59.599959 IP 192.168.101.1 > 192.168.103.1: ICMP echo reply, id 5, seq 0, length 80 13:29:59.599959 IP 192.168.101.1 > 192.168.103.1: ICMP echo reply, id 5, seq 1, length 80 13:29:59.599959 IP 192.168.101.1 > 192.168.103.1: ICMP echo reply, id 5, seq 2, length 80 13:29:59.599959 IP 192.168.101.1 > 192.168.103.1: ICMP echo reply, id 5, seq 3, length 80 13:29:59.599959 IP 192.168.101.1 > 192.168.103.1: ICMP echo reply, id 5, seq 4, length 80
Tcpdump过滤器示例
示例 1：
要捕获Src IP或Dst IP = 192.168.101.1和Src port或Dst port = TCP/UDP 23，请输入以下命令：
Options: -n host 192.168.101.1 and port 23
示例 2：
要捕获Src IP = 192.168.101.1和Src port = TCP/UDP 23，请输入以下命令：
Options: -n src 192.168.101.1 and src port 23
示例 3：
要捕获Src IP = 192.168.101.1和Src port = TCP 23，请输入以下命令：
Options: -n src 192.168.101.1 and tcp and src port 23
示例 4：
要捕获Src IP = 192.168.101.1并查看数据包的MAC地址，请添加“e”选项，然后输入以下命令：
Options: -ne src 192.168.101.1 17:57:48.709954 6c:41:6a:a1:2b:f6 > a8:9d:21:93:22:90, ethertype IPv4 (0x0800), length 58: 192.168.101.1.23 > 192.168.103.1.25420:
Flags [S.], seq 3694888749, ack 1562083610, win 8192, options [mss 1380], length 0
示例 5：
要在捕获10个数据包后退出，请输入以下命令：
Options: -n -c 10 src 192.168.101.1 18:03:12.749945 IP 192.168.101.1.23 > 192.168.103.1.27287: Flags [.], ack 3758037348, win 32768, length 0 18:03:12.749945 IP 192.168.101.1.23 > 192.168.103.1.27287: Flags [P.], ack 1, win 32768, length 2 18:03:12.949932 IP 192.168.101.1.23 > 192.168.103.1.27287: Flags [P.], ack 1, win 32768, length 10 18:03:13.249971 IP 192.168.101.1.23 > 192.168.103.1.27287: Flags [.], ack 3, win 32768, length 0 18:03:13.249971 IP 192.168.101.1.23 > 192.168.103.1.27287: Flags [P.], ack 3, win 32768, length 2 18:03:13.279969 IP 192.168.101.1.23 > 192.168.103.1.27287: Flags [.], ack 5, win 32768, length 0 18:03:13.279969 IP 192.168.101.1.23 > 192.168.103.1.27287: Flags [P.], ack 5, win 32768, length 10 18:03:13.309966 IP 192.168.101.1.23 > 192.168.103.1.27287: Flags [.], ack 7, win 32768, length 0 18:03:13.309966 IP 192.168.101.1.23 > 192.168.103.1.27287: Flags [P.], ack 7, win 32768, length 12 18:03:13.349972 IP 192.168.101.1.23 > 192.168.103.1.27287: Flags [.], ack 9, win 32768, length 0
示例 6：
要将捕获写入名称为capture.pcap的文件并通过FTP将其复制到远程服务器，请输入以下命令：
Options: -w capture.pcap host 192.168.101.1 CTRL + C <- to stop the capture > file copy 10.229.22.136 ftp / capture.pcap Enter password for ftp@10.229.22.136: Copying capture.pcap Copy successful. >
使用FTD LINA引擎捕获
要求
1.使用以下过滤器在FTD上启用两个捕获：
| 源 IP |
192.168.103.1 |
| 目的 IP |
192.168.101.1 |
| 协议 |
ICMP |
| 接口 |
内部 |
| 源 IP |
192.168.103.1 |
| 目的 IP |
192.168.101.1 |
| 协议 |
ICMP |
| 接口 |
外部 |
2.从Host-A(192.168.103.1)对Host-B(192.168.101.1)执行ping操作并检查捕获。
解决方案
步骤1.启用捕获：
> capture CAPI interface INSIDE match icmp host 192.168.103.1 host 192.168.101.1 > capture CAPO interface OUTSIDE match icmp host 192.168.101.1 host 192.168.103.1
步骤2.检查CLI中的捕获。
从Host-A ping Host-B:
> show capture capture CAPI type raw-data interface INSIDE [Capturing - 752 bytes] match icmp host 192.168.103.1 host 192.168.101.1 capture CAPO type raw-data interface OUTSIDE [Capturing - 720 bytes] match icmp host 192.168.101.1 host 192.168.103.1
由于INSIDE接口上的Dot1Q报头，两个捕获的大小不同，如下面的输出示例所示：
> show capture CAPI 8 packets captured 1: 17:24:09.122338 802.1Q vlan#1577 P0 192.168.103.1 > 192.168.101.1: icmp: echo request 2: 17:24:09.123071 802.1Q vlan#1577 P0 192.168.101.1 > 192.168.103.1: icmp: echo reply 3: 17:24:10.121392 802.1Q vlan#1577 P0 192.168.103.1 > 192.168.101.1: icmp: echo request 4: 17:24:10.122018 802.1Q vlan#1577 P0 192.168.101.1 > 192.168.103.1: icmp: echo reply 5: 17:24:11.119714 802.1Q vlan#1577 P0 192.168.103.1 > 192.168.101.1: icmp: echo request 6: 17:24:11.120324 802.1Q vlan#1577 P0 192.168.101.1 > 192.168.103.1: icmp: echo reply 7: 17:24:12.133660 802.1Q vlan#1577 P0 192.168.103.1 > 192.168.101.1: icmp: echo request 8: 17:24:12.134239 802.1Q vlan#1577 P0 192.168.101.1 > 192.168.103.1: icmp: echo reply 8 packets shown
> show capture CAPO 8 packets captured 1: 17:24:09.122765 192.168.103.1 > 192.168.101.1: icmp: echo request 2: 17:24:09.122994 192.168.101.1 > 192.168.103.1: icmp: echo reply 3: 17:24:10.121728 192.168.103.1 > 192.168.101.1: icmp: echo request 4: 17:24:10.121957 192.168.101.1 > 192.168.103.1: icmp: echo reply 5: 17:24:11.120034 192.168.103.1 > 192.168.101.1: icmp: echo request 6: 17:24:11.120263 192.168.101.1 > 192.168.103.1: icmp: echo reply 7: 17:24:12.133980 192.168.103.1 > 192.168.101.1: icmp: echo request 8: 17:24:12.134194 192.168.101.1 > 192.168.103.1: icmp: echo reply 8 packets shown
使用FTD LINA引擎捕获 — 通过HTTP导出捕获
要求
使用浏览器导出在前面的场景中获取的捕获。
解决方案
要使用浏览器导出捕获，您需要：
- 启用HTTPS服务器。
- 允许HTTPS访问。
默认情况下，HTTPS服务器处于禁用状态，且不允许访问：
> show running-config http
>
步骤1.导航到设备>平台设置，单击New Policy，然后选择Threat Defense Settings:
指定策略名称和设备目标：
步骤2.启用HTTPS服务器并添加要允许通过HTTPS访问FTD设备的网络：
保存并部署。
在策略部署时，可以启用debug http以查看HTTP服务的启动：
> debug http 255 debug http enabled at level 255. http_enable: Enabling HTTP server HTTP server starting.
FTD CLI的结果是：
> unebug all > show run http http server enable http 192.168.103.0 255.255.255.0 INSIDE
在Host-A(192.168.103.1)上打开浏览器，使用此URL下载第一个捕获：https://192.168.103.62/capture/CAPI/pcap/CAPI.pcap。
供参考：
| 启用HTTP服务器的FTD数据接口的IP |
|
| FTD捕获的名称 |
|
| 下载的文件的名称 |
对于第二次捕获，请使用https://192.168.103.62/capture/CAPO/pcap/CAPO.pcap。
使用FTD LINA引擎捕获 — 通过FTP/TFTP/SCP导出捕获
要求
使用Cisco IOS®协议导出在早期场景中获取的捕获。
解决方案
将捕获导出到FTP服务器：
firepower# copy /pcap capture:CAPI ftp://ftp_username:ftp_password@192.168.78.73/CAPI.pcap Source capture name [CAPI]? Address or name of remote host [192.168.78.73]? Destination username [ftp_username]? Destination password [ftp_password]? Destination filename [CAPI.pcap]? !!!!!! 114 packets copied in 0.170 secs
firepower#
将捕获导出到TFTP服务器：
firepower# copy /pcap capture:CAPI tftp://192.168.78.73 Source capture name [CAPI]? Address or name of remote host [192.168.78.73]? Destination filename [CAPI]? !!!!!!!!!!!!!!!! 346 packets copied in 0.90 secs
firepower#
将捕获导出到SCP服务器：
firepower# copy /pcap capture:CAPI scp://scp_username:scp_password@192.168.78.55 Source capture name [CAPI]? Address or name of remote host [192.168.78.55]? Destination username [scp_username]? Destination filename [CAPI]? The authenticity of host '192.168.78.55 (192.168.78.55)' can't be established. RSA key fingerprint is <cb:ca:9f:e9:3c:ef:e2:4f:20:f5:60:21:81:0a:85:f9:02:0d:0e:98:d0:9b:6c:dc:f9:af:49:9e:39:36:96:33>(SHA256). Are you sure you want to continue connecting (yes/no)? yes Warning: Permanently added '192.168.78.55' (SHA256) to the list of known hosts. !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! 454 packets copied in 3.950 secs (151 packets/sec)
firepower#
从FTD卸载捕获。目前，如果需要从FTD卸载捕获，最简单的方法是执行以下步骤：
1.从Lina - copy /pcap capture:<cap_name> disk0:
2.从FPR根 — mv /ngfw/mnt/disk0/<cap_name> /ngfw/var/common/
3.从FMC UI - System > Health > Monitor > Device > Advanced Troubleshooting，然后在字段中输入<cap_name>并下载。
使用FTD LINA引擎捕获 — 跟踪实际流量数据包
要求
使用以下过滤器在FTD上启用捕获：
| 源 IP |
192.168.103.1 |
| 目的 IP |
192.168.101.1 |
| 协议 |
ICMP |
| 接口 |
内部 |
| 数据包跟踪 |
是 |
| 跟踪数据包的数量 |
100 |
从Host-A(192.168.103.1)Host-B(192.168.101.1)执行ping操作并检查捕获。
解决方案
跟踪实际数据包对于排除连接问题非常有用。它允许您查看数据包经过的所有内部检查。添加trace detail关键字并指定要跟踪的数据包数量。默认情况下，FTD跟踪前50个入口数据包。
在这种情况下，为FTD在INSIDE接口上接收的前100个数据包启用带有跟踪详细信息的捕获：
> capture CAPI2 interface INSIDE trace detail trace-count 100 match icmp host 192.168.103.1 host 192.168.101.1
从Host-A ping Host-B并检查结果：
捕获的数据包包括：
> show capture CAPI28 packets captured 1: 18:08:04.232989 802.1Q vlan#1577 P0 192.168.103.1 > 192.168.101.1: icmp: echo request 2: 18:08:04.234622 802.1Q vlan#1577 P0 192.168.101.1 > 192.168.103.1: icmp: echo reply 3: 18:08:05.223941 802.1Q vlan#1577 P0 192.168.103.1 > 192.168.101.1: icmp: echo request 4: 18:08:05.224872 802.1Q vlan#1577 P0 192.168.101.1 > 192.168.103.1: icmp: echo reply 5: 18:08:06.222309 802.1Q vlan#1577 P0 192.168.103.1 > 192.168.101.1: icmp: echo request 6: 18:08:06.223148 802.1Q vlan#1577 P0 192.168.101.1 > 192.168.103.1: icmp: echo reply 7: 18:08:07.220752 802.1Q vlan#1577 P0 192.168.103.1 > 192.168.101.1: icmp: echo request 8: 18:08:07.221561 802.1Q vlan#1577 P0 192.168.101.1 > 192.168.103.1: icmp: echo reply 8 packets shown
此输出显示第一个数据包的跟踪。感兴趣的部分：
- 在第12阶段，可以看到“正向流”。这是LINA引擎调度阵列（实际上是指内部操作顺序）。
- 阶段13是FTD将数据包发送到Snort实例的位置。
- 在第14阶段，可以看到Snort判定。
> show capture CAPI2 packet-number 1 trace detail
8 packets captured
1: 18:08:04.232989 000c.2998.3fec a89d.2193.2293 0x8100 Length: 78
802.1Q vlan#1577 P0 192.168.103.1 > 192.168.101.1: icmp: echo request (ttl 128, id 3346)
Phase: 1
Type: CAPTURE
... output omitted ...
Phase: 12
Type: FLOW-CREATION
Subtype:
Result: ALLOW
Config:
Additional Information:
New flow created with id 195, packet dispatched to next module
Module information for forward flow ...
snp_fp_inspect_ip_options
snp_fp_snort
snp_fp_inspect_icmp
snp_fp_adjacency
snp_fp_fragment
snp_ifc_stat
Module information for reverse flow ...
snp_fp_inspect_ip_options
snp_fp_inspect_icmp
snp_fp_snort
snp_fp_adjacency
snp_fp_fragment
snp_ifc_stat
Phase: 13
Type: EXTERNAL-INSPECT
Subtype:
Result: ALLOW
Config:
Additional Information:
Application: 'SNORT Inspect'
Phase: 14
Type: SNORT
Subtype:
Result: ALLOW
Config:
Additional Information:
Snort Verdict: (pass-packet) allow this packet
... output omitted ...
Result:
input-interface: OUTSIDE
input-status: up
input-line-status: up
output-interface: OUTSIDE
output-status: up
output-line-status: up
Action: allow
1 packet shown
>
6.2以后FMC软件版本中的捕获工具
在FMC版本6.2.x中，引入了一个新的数据包捕获向导。导航到设备>设备管理，然后单击故障排除图标。然后选择Advanced Troubleshooting，最后选择Capture w/Trace。
选择Add Capture以创建FTD捕获：
当前的FMC UI限制如下：
- 无法指定Src和Dst端口
- 只能匹配基本IP协议
- 无法为LINA引擎ASP丢弃启用捕获
解决方法 — 使用FTD CLI
从FMC UI应用捕获后，捕获会运行：
FTD CLI上的捕获：
> show capture capture CAPI%intf=INSIDE% type raw-data trace interface INSIDE [Capturing - 0 bytes] match ip host 192.168.0.10 host 192.168.2.10 >
在6.2之后FMC上跟踪实际数据包
在FMC 6.2.x上，Capture w/Trace向导允许您捕获和跟踪FTD上的实际数据包：
您可以在FMC UI中检查跟踪的数据包：
FTD Packet Tracer实用程序
要求
使用Packet Tracer实用程序处理此流，并检查内部处理数据包的方式：
| Ingress 接口 |
内部 |
| 协议 |
ICMP回应请求 |
| 源 IP |
192.168.103.1 |
| 目的 IP |
192.168.101.1 |
解决方案
Packet Tracer生成虚拟数据包。如本例所示，数据包接受Snort检测。在Snort级别同时捕获的捕获(capture-traffic)显示ICMP回应请求：
> packet-tracer input INSIDE icmp 192.168.103.1 8 0 192.168.101.1 Phase: 1 Type: CAPTURE Subtype: Result: ALLOW Config: Additional Information: MAC Access list Phase: 2 Type: ACCESS-LIST Subtype: Result: ALLOW Config: Implicit Rule Additional Information: MAC Access list Phase: 3 Type: ROUTE-LOOKUP Subtype: Resolve Egress Interface Result: ALLOW Config: Additional Information: found next-hop 192.168.101.1 using egress ifc OUTSIDE Phase: 4 Type: ACCESS-LIST Subtype: log Result: ALLOW Config: access-group CSM_FW_ACL_ global access-list CSM_FW_ACL_ advanced permit ip 192.168.103.0 255.255.255.0 192.168.101.0 255.255.255.0 rule-id 268436482 event-log both access-list CSM_FW_ACL_ remark rule-id 268436482: ACCESS POLICY: FTD5515 - Mandatory/1 access-list CSM_FW_ACL_ remark rule-id 268436482: L4 RULE: Allow ICMP Additional Information: This packet is sent to snort for additional processing where a verdict is reached ... output omitted ... Phase: 12 Type: FLOW-CREATION Subtype: Result: ALLOW Config: Additional Information: New flow created with id 203, packet dispatched to next module
Phase: 13
Type: SNORT
Subtype:
Result: ALLOW
Config:
Additional Information:
Snort Trace:
Packet: ICMP
AppID: service ICMP (3501), application unknown (0)
Firewall: allow rule, id 268440225, allow
NAP id 2, IPS id 0, Verdict PASS
Snort Verdict: (pass-packet) allow this packet
Result: input-interface: INSIDE input-status: up input-line-status: up output-interface: OUTSIDE output-status: up output-line-status: up Action: allow >
Packet Tracer测试时的Snort级别捕获显示虚拟数据包：
> capture-traffic Please choose domain to capture traffic from: 0 - management0 1 - Router Selection? 1 Please specify tcpdump options desired. (or enter '?' for a list of supported options) Options: -n 13:27:11.939755 IP 192.168.103.1 > 192.168.101.1: ICMP echo request, id 0, seq 0, length 8
6.2以后FMC软件版本的Packet Tracer UI工具
在FMC版本6.2.x中，引入了Packet Tracer UI工具。该工具与捕获工具以相同的方式访问，并允许您从FMC UI在FTD上运行Packet Tracer:
相关信息
修订历史记录
| 版本 | 发布日期 | 备注 |
|---|---|---|
3.0 |
06-Dec-2024 |
固定格式、SEO、品牌、间距、替换文本。 |
1.0 |
21-Nov-2017 |
初始版本 |
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