Add switch OS description and factory reset instructions to README

- Document BOSS v7.9.6 as the switch firmware in Requirements section
- Add factory reset procedure (boot config flags factory) to Troubleshooting
- Note when a wipe is and is not necessary

https://claude.ai/code/session_01JR2EMK7rwrZJowpstcaxQ6

README.md

@@ -14,6 +14,10 @@ The setup script uses `apt`, `systemd`, `picocom`, and Docker. It will not run o
 
 The switch UI itself (the browser interface) works from any OS — phone, tablet, Mac, Windows, Linux.
 
+**Switch OS: BOSS (Baystack Operating System Software) v7.9.6**
+
+BOSS is the firmware that runs on Avaya / Extreme ERS switches. This project is written and tested against BOSS v7.9.6 on the ERS 59100GTS-PWR+. It is not Cisco IOS or any other vendor's CLI — commands are different. BOSS firmware is pre-installed on the switch and does not need to be downloaded or installed.
+
 ---
 
 ## Physical Setup — First Time Out of the Box
@@ -505,6 +509,21 @@ Read the error text — the switch says exactly what was wrong. Fix the configur
 **Host key rejection after switch reset**
 Re-pin: `ssh-keyscan -H 192.168.99.1 > /etc/switch-manager/known_hosts`
 
+**Factory reset — wiping a previously configured switch**
+
+If the switch has a previous config you want to clear before starting fresh, do this via the console cable:
+
+```
+enable
+boot config flags factory
+save config
+boot
+```
+
+The switch will reboot into factory defaults — blank config, default credentials (`admin` / no password), and the default management IP `192.168.1.1` on VLAN 1. Then follow the setup steps from Step 5 onwards.
+
+> When to wipe: if the switch has unknown previous configuration, unknown passwords, or you want a guaranteed clean slate. If the switch already responds to `admin` with no password and has no unexpected VLANs or ACLs, a wipe is not required — you can configure over the existing state.
+
 **ctrld not filtering DNS**
 Check DHCP option 6 is set to the ctrld machine's IP on each VLAN pool. Check ctrld is running: `ctrld status`. Check the switch is handing out the right DNS: from a device, run `nslookup example.com` and verify the server IP matches.