喜大普奔，XR 终于出了内置的 Packet Tracer 工具了（类似的 XE 中也提供类似的 feature，不过应该是很早就支持了）。该工具作用是用于跟踪数据包进入路由器后经过的组件,监视数据包信息，查找数据包丢失或最后一次见到的位置 .
如我们常用的 ACL 匹配数据包一样，需要设定特定的匹配条件，然后执行该内置的工具进行数据包的匹配。
Packet Tracer Conditions - Offset/Value/Mask #
如何生成这个匹配条件，我们提供了一个 web 工具，如下，包含丰富的数据包类型：
该 Web 工具发布在 Github，可以参考以下 link 完成安装使用：
https://github.com/xr-packet-tracer/xr-embedded-packet-tracer-condition-generator
[root@xuxing ~]# wget -qO- https://raw.githubusercontent.com/nvm-sh/nvm/v0.35.3/install.sh | bash
[root@xuxing ~]# nvm install 12.14.1 <<< 安装12.14.1的node
[root@xuxing ~]# git clone https://github.com/xr-packet-tracer/xr-embedded-packet-tracer-condition-generator
[root@xuxing ~]# cd xr-embedded-packet-tracer-condition-generator/
[root@xuxing xr-embedded-packet-tracer-condition-generator]# npm install
[root@xuxing xr-embedded-packet-tracer-condition-generator]# npm start
Compiled successfully!
You can now view packet-tracer-condition in the browser.
Local: http://localhost:3000/
On Your Network: http://10.75.49.238:3000/
Note that the development build is not optimized.
To create a production build, use npm run build.
- 2023-01-26 更新如下：
上述 install 过程是在一台 centos7 上操作了，默认安装 nvm 后 node 和 npm 的 version 都很高；这样就导致后续执行 npm install 和 start 的时候会有很多的报错，导致服务起不来，所以这里使用了nvm install 12.14.1 更改 node 的 version 为 12.14.1，这个时候执行 node -v 和 npm -v 就会看到以下的版本：
$ node -v
v12.14.1
$ npm -v
6.13.4
后续我又尝试在 MAC OS 上装了一遍，发现 MAC OS 上即使 node/npm 的 version 很高有报错， 最后的服务也可以起起来，不得不服！！！
# brew install node
# git clone https://github.com/xr-packet-tracer/xr-embedded-packet-tracer-condition-generator
# npm install
# npm start
~ ❯ npm -v
9.3.1
~ ❯ node -v
v19.5.0
~ ❯
Packet Trace Use Case #
这里使用一个很简单的环境测试下这个 feature，用来抓取 ICMP 数据包进入路由器后的路径。
RP/0/RSP0/CPU0:9901-2#packet-trace condition interface tenGigE 0/0/0/30
RP/0/RSP0/CPU0:9901-2#packet-trace condition 1 Offset 23 Value 0x01 Mask 0xff
RP/0/RSP0/CPU0:9901-2#packet-trace condition 2 Offset 26 Value 0x7b7b7a02 Mask 0xffffffff
RP/0/RSP0/CPU0:9901-2#packet-trace condition 3 Offset 30 Value 0x7b7b7a01 Mask 0xffffffff
RP/0/RSP0/CPU0:9901-2#packet-trace start
RP/0/RSP0/CPU0:9901-2#ping 123.123.122.2 count 1000
Wed Aug 26 04:11:01.157 HKT
Type escape sequence to abort.
Sending 1000, 100-byte ICMP Echos to 123.123.122.2, timeout is 2 seconds:
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!
Success rate is 100 percent (1000/1000), round-trip min/avg/max = 1/1/12 ms
RP/0/RSP0/CPU0:9901-2#show packet-trace results
Wed Aug 26 04:11:14.893 HKT
T: D - Drop counter; P - Pass counter
Location | Source | Counter | T | Last-Attribute | Count
------------ ------------ ------------------------- - ---------------------------------------- ---------------
0/0/CPU0 NP1 PACKET_MARKED P TenGigE0_0_0_30 1000
0/0/CPU0 NP1 PACKET_TO_PUNT P 1000
0/RSP0/CPU0 SPP_PD PKT_SPP_PD_PUNT_DROP D 1
Other userful command #
// 清除之前的一些设置
#packet-trace atop
#clear packet-trace conditions all
#clear packet-trace counters all
//show command
#show packet-trace status
#show packet-trace status detail
#show packet-trace descriptions
#show packet-trace results counter PACKET_MARKED location 0/0/CPU0
#show packet-trace results counter PACKET_MARKED source NP1 location 0/0/CPU0
限制 #
7.1.2 开始，5th, 4th and 3rd generation line cards (aka Lightspeed Plus, Lighstpeed, Tomahawk).