📝 Update Phase 1 & 2 with Alpine-specific fixes (ash vs bash, rsync install, SSH key details)

Midori's Linux Dojo 🌸/Phase 2 - Networking/Exercises.md

@@ -1,6 +1,6 @@
 # 🌐 Phase 2: Networking
 
-> Goal: Machines communicate — ping, SSH, file transfers
+> Goal: Machines communicate — ping, SSH, file transfers, services
 
 ---
 
@@ -18,50 +18,76 @@ ping -c 4 10.0.1.1        # From alpine-2 → alpine-1
 # Check ARP table
 ip neigh
 
-# Advanced network tools
-ip addr                 # All interfaces
-ip route                # Routing table
-traceroute 10.0.1.2     # Path between VMs
+# tcpdump (packet capture) — Alpine needs install first
+apk add tcpdump
+tcpdump -i eth0 -c 5 icmp &
+ping -c 3 10.0.1.2
 ```
 
 ### 📝 Questions:
 1. What's the MAC address of the other VM?
 2. Can you ping alpine-hop (10.0.1.3) from alpine-1?
+3. What subnet are you on? How many usable hosts?
 
 ---
 
 ## 🎯 Exercise 2 — SSH Keys
 
 ```bash
-# Generate an SSH key
+# Step 1 — Generate an SSH key pair
 ssh-keygen -t ed25519
+# Press Enter for all prompts (no passphrase)
 
-# Copy to the other VM
+# Step 2 — What just got created?
+ls -la ~/.ssh/
+# id_ed25519      ← your PRIVATE key (NEVER share this!)
+# id_ed25519.pub  ← your PUBLIC key (safe to share)
+
+# Step 3 — Copy your public key to alpine-2
 ssh-copy-id root@10.0.1.2
+# Enter root password for alpine-2 when prompted
 
-# Test passwordless login
+# Step 4 — Test passwordless login!
 ssh root@10.0.1.2 'hostname; uptime'
+# Should work WITHOUT asking for a password 🎉
+
+# Step 5 — See what ssh-copy-id did
+ssh root@10.0.1.2 'cat ~/.ssh/authorized_keys'
 ```
 
+### 💡 How it works
+Your public key is appended to `~/.ssh/authorized_keys` on the target. When you SSH, the server checks if you have the matching **private key** — no password needed! 🔑
+
 ---
 
-## 🎯 Exercise 3 — File Transfer
+## 🎯 Exercise 3 — File Transfer (SCP & RSYNC)
 
 ```bash
-# SCP (secure copy)
-echo "Secret message" > /root/secret.txt
-scp /root/secret.txt root@10.0.1.2:/root/
+# SCP — single files
+echo "CCNA study notes" > /root/study.txt
+scp /root/study.txt root@10.0.1.2:/root/
 
-# RSYNC (sync directories)
+# Verify
+ssh root@10.0.1.2 'cat /root/study.txt'
+
+# RSYNC — directories (need to install on Alpine)
+apk add rsync
 rsync -av /root/lab/ root@10.0.1.2:/root/lab-backup/
+
+# Verify the backup
+ssh root@10.0.1.2 'ls -la /root/lab-backup/'
 ```
 
+### 📝 Questions:
+1. What's the difference between `scp` and `rsync`?
+2. What does the `-a` flag in `rsync -av` mean? (hint: check `man rsync`)
+
 ---
 
 ## 🎯 Exercise 4 — Network Services
 
 ```bash
-# Check listening ports
+# Check what's listening on your VM
 ss -tlnp
 
 # Start a simple HTTP server on alpine-1
@@ -70,16 +96,33 @@ python3 -m http.server 8080 &
 # Access it from alpine-2
 curl http://10.0.1.1:8080/
 
-# Kill the server
+# See the connection in your server logs
+# Kill the server when done
 kill %1
 ```
 
 ---
 
+## 🎯 Bonus: CCNA Challenge
+
+```bash
+# From alpine-1, can you SSH to alpine-hop?
+ssh root@10.0.1.3
+
+# Check the routing table
+ip route
+
+# Why can alpine-1 reach alpine-hop (10.0.1.3)?
+# Why can't alpine-1 reach the internet?
+```
+
+---
+
 ## ✅ Phase 2 Checklist
-- [ ] Ping between VMs
-- [ ] SSH key-based auth
+
+- [ ] Ping and ARP (`ip neigh`)
+- [ ] SSH key generation and passwordless login
 - [ ] File transfer with `scp` / `rsync`
-- [ ] Network services
+- [ ] Running a network service
 
 **Previous:** [[Phase 1 - Walking]] | **Next:** [[Phase 3 - Users and Files]]