diff --git a/_data/navigation.yml b/_data/navigation.yml
index 64273ac..e256b97 100644
--- a/_data/navigation.yml
+++ b/_data/navigation.yml
@@ -6,7 +6,7 @@ main:
   - title: "Research"
     url: /research/
   - title: "Notes"
-    url: /study/
+    url: /notes/
   - title: "Posts"
     url: /posts/
   # - title: "Categories"
@@ -35,10 +35,10 @@ study:
 linux:
   - title: Linux
     children:
-      - title: "Intro"
-        url: /notes/linux/
       - title: "Commands"
         url: /notes/linux/cmd
+      - title: "Iptables"
+        url: /notes/linux/iptables/
 
 ds:
   - title: Content
diff --git a/_pages/00-dpu-intro.md b/_pages/00-dpu-intro.md
index 99b8bc2..d7eaa26 100644
--- a/_pages/00-dpu-intro.md
+++ b/_pages/00-dpu-intro.md
@@ -66,13 +66,49 @@ SmartNIC/DPU refers to a new generation of network adapters. DPU is a SoC, with
   - IP: 198.168.100.x
   - netmask: 255.255.255.0
 
+## Accessing Network from SmartNIC [3][4]
+### Preparation
+- Stop ovs.
+- Make sure interfaces `tmfifo_net0` are assigned with an ip address on both host and SmartNIC.
+
+
+### Setting Host Iptables
+
+```console
+# Turn on IPv4 forwarding
+sfwu22@dpu:~$ echo 1 | sudo tee /proc/sys/net/ipv4/ip_forward
+
+# Configure IP forwarding rules for the internet-facing interface eno1
+sfwu22@dpu:~$ iptables -A FORWARD -o eno1 -j ACCEPT
+sfwu22@dpu:~$ iptables -A FORWARD -m state --state ESTABLISHED,RELATED -i eno1 - j ACCEPT
+
+# Configure the NAT rule for the internet-facing interface eno1
+sfwu22@dpu:~$ iptables -t nat -A POSTROUTING -o eno1 -j MASQUERADE
+```
+### DNS Server
+Check the DNS server in current domain. The DNS server address can be checked and configured with:
+```console
+# On host/SmartNIC
+sfwu22@proj88:~$ systemd-resolve --status
+
+# Set DNS server of SmartNIC
+# For group SmartNIC
+sfwu22@dpu:~$ echo "nameserver 192.168.50.254" | sudo tee /etc/resolv.conf
+# For CloudLab SmartNIC
+sfwu22@dpu:~$ echo "nameserver 8.8.8.8" | sudo tee /etc/resolv.conf
+```
+### Proxy Server
+If host sits behind a proxy server, SmartNIC should be configured with the same proxy server. 
+
+Then SmartNIC is good to go!
+
 ## Additional Configuration
 
 - Firmware update.
 
-- Subfunction configuration[^2].
+- Subfunction configuration[2].
 
-- Running examples. Examples are located in `/opt/mellanox/doca/application` in DPU. Take `url_filter ` as the example[^1].
+- Running examples. Examples are located in `/opt/mellanox/doca/application` in DPU. Take `url_filter ` as the example[1].
 
   - Preparation 1: configure corresponding SF and start regx engine.
 
@@ -88,5 +124,7 @@ SmartNIC/DPU refers to a new generation of network adapters. DPU is a SoC, with
 
 ## Reference
 
-[^1]: [URL Filter :: NVIDIA DOCA SDK Documentation](https://docs.nvidia.com/doca/sdk/url-filter/index.html)
-[^2]: [Scalable Function (SFs) :: NVIDIA DOCA SDK Documentation](https://docs.nvidia.com/doca/sdk/scalable-functions/index.html)
+[1]: [URL Filter :: NVIDIA DOCA SDK Documentation](https://docs.nvidia.com/doca/sdk/url-filter/index.html)
+[2]: [Scalable Function (SFs) :: NVIDIA DOCA SDK Documentation](https://docs.nvidia.com/doca/sdk/scalable-functions/index.html)
+[3]: [NVIDIA Mellanox Bluefield-2 SmartNIC Hands-On Tutorial: “Rig for Dive” — Part I: Install Drivers and Access the SmartNIC](https://medium.com/codex/getting-your-hands-dirty-with-mellanox-bluefield-2-dpus-deployed-in-cloudlabs-clemson-facility-bcb4e689c7e6)
+[4]: [Configuring NVIDIA BlueField2 SmartNIC](https://insujang.github.io/2022-01-06/configuring-nvidia-bluefield2-smartnic/)
diff --git a/_pages/08-linux-commands.md b/_pages/08-linux-commands.md
index fb390ae..a4008da 100644
--- a/_pages/08-linux-commands.md
+++ b/_pages/08-linux-commands.md
@@ -5,15 +5,20 @@ sidebar:
     nav: "linux" 
 ---
 
-Here is some useful Linux commands that are frequently used.
+Here are some useful Linux commands.
 
 # Network Configuration
 
 ## ip
 
-
-
 ## ifconfig
+``sudo ifconfig [interface] [ip addr] netmask [netmask] [up/down]`` 
+```console
+sfwu22@proj88:~$ sudo ifconfig tmfifo_net0 192.168.100.1 netmask 255.255.255.0 up
+```
+
+## iptables
+Check [this link](/notes/linux/iptables).
 
 # File Transmission
 
@@ -23,14 +28,14 @@ Here is some useful Linux commands that are frequently used.
 
 On Linux platforms
 
-```
-wget [url]
+```console
+sfwu22@proj88:~$ wget [url]
 ```
 
 For Windows, `wget` is the alias for `Invoke-WebRequest`. One must specify url and file name to correctly download a file.
 
-```
-wget -Uri [url] -OutFile "filename.xxx"
+```console
+sfwu22@proj88:~$ wget -Uri [url] -OutFile "filename.xxx"
 ```
 
 
@@ -41,8 +46,8 @@ wget -Uri [url] -OutFile "filename.xxx"
 
 Transmitting files from Windows to Linux.
 
-```
-scp C:\Users\shaofeng\filename shaofeng@[target_alias/ip]:/home/shaofeng/directory
+```console
+sfwu22@proj88:~$ scp C:\Users\shaofeng\filename shaofeng@[target_alias/ip]:/home/shaofeng/directory
 ```
 
 
diff --git a/_pages/08-linux-iptables.md b/_pages/08-linux-iptables.md
new file mode 100644
index 0000000..9bb112b
--- /dev/null
+++ b/_pages/08-linux-iptables.md
@@ -0,0 +1,40 @@
+---
+permalink: /notes/linux/iptables/
+title: "Iptables"
+sidebar:
+    nav: "linux" 
+---
+`iptables` is a powerful tool for managing firewall rules, NAT and other network functions.
+
+Note: 
+- Never use any command to delete all rules or a single rule without checking in ``iptable``, especially for rules relating to 
+**gateways, ssh protocol, packet drop**. It may make a remote server forever out of reach unless on-site resetting.
+- Rules in the same table are **checked from rule number 1 to the last rule one by one**. Since the last rule in a table is usually "drop all packets", adding rules after the last rule is meaningless. 
+
+# Commands
+## View Rules
+```console
+# view rules in INPUT, OUTPUT, FORWARDING table
+sfwu22@proj88:~$ sudo iptables -nvL --line-number
+...
+# view rules in nat table
+sfwu22@proj88:~$ sudo iptables -t nat -nvL --line-number
+```
+
+## Add/Insert Rules
+```console
+# add rules to the end of a table
+sfwu22@proj88:~$ sudo iptables -nvL --line-number
+...
+# insert rule into a table
+sfwu22@proj88:~$ sudo iptables -t nat -nvL --line-number
+```
+
+## Delete Rules
+```console
+# delete rule number 1 from INPUT chain
+sfwu22@proj88:~$ sudo iptables -D FORWARD 1
+
+# delete rule number 1 from nat table POSTROUTING chain
+sfwu22@proj88:~$ sudo iptables -t nat -D POSTROUTING 1
+```
\ No newline at end of file
diff --git a/_pages/08-linux.md b/_pages/08-linux.md
index 2539a2d..71ac6e9 100644
--- a/_pages/08-linux.md
+++ b/_pages/08-linux.md
@@ -1,8 +1,8 @@
 ---
-permalink: /notes/linux
+permalink: /notes/linux/
 title: "Linux Notes"
 sidebar:
     nav: "linux" 
 ---
 
-**Notes about ![](https://img.shields.io/badge/Linux-FCC624?style=flat-square&logo=Linux&logoColor=white) **
+**Notes about ![](https://img.shields.io/badge/Linux-FCC624?style=flat-square&logo=Linux&logoColor=white).**
diff --git a/_pages/study.md b/_pages/notes.md
similarity index 86%
rename from _pages/study.md
rename to _pages/notes.md
index c32d512..c2083db 100644
--- a/_pages/study.md
+++ b/_pages/notes.md
@@ -1,5 +1,5 @@
 ---
-permalink: /study/
+permalink: /notes/
 title: "Notes"
 sidebar:
   nav: "study"