diff --git a/notes/计算机网络.md b/notes/计算机网络.md
index 20ec0591..ac8245c0 100644
--- a/notes/计算机网络.md
+++ b/notes/计算机网络.md
@@ -333,9 +333,9 @@ CSMA/CD 表示载波监听多点接入 / 碰撞检测。
 
 从表面上看，使用集线器的局域网在物理上是一个星型网。但是集线器使用电子器件来模拟实际缆线的工作，逻辑上仍是一个总线网，整个系统仍像一个传统以太网那样运行。
 
-![](https://github.com/CyC2018/InterviewNotes/blob/master/pics//897a4f4e-2683-44e1-a26a-c0d0234dc576.jpg)
+![](https://github.com/CyC2018/InterviewNotes/blob/master/pics//3294ff06-f942-425e-aecc-ca04e45566d4.png)
 
-![](https://github.com/CyC2018/InterviewNotes/blob/master/pics//40c3f8e5-3a20-45b6-a60c-77b9b952e104.jpg)
+![](https://github.com/CyC2018/InterviewNotes/blob/master/pics//b56ef52e-3d0f-4cdd-97dc-eaed893444a5.jpg)
 
 ## MAC 层
 
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