邊做邊學，順便留個筆記，若有錯誤請不吝指教。
Junos基本操作及root密碼設定可參考我之前的文章：Juniper Junos基本操作、root密碼設定
所有Juniper相關文章列表：Juniper JunOS 系列文章列表
所有設備都應該定期更新韌體(Firmware)版本以降低資安風險。
更新韌體前要先進行版本確認，在命令模式下執行下列指令：
KerKer@sw1> show version
fpc0:
--------------------------------------------------------------------------
Model: ex4600-40f
Junos: 18.1R3-S9.1
JUNOS Base OS Software Suite [18.1R3-S9.1]
JUNOS Base OS boot [18.1R3-S9.1]
JUNOS Crypto Software Suite [18.1R3-S9.1]
JUNOS Crypto Software Suite [18.1R3-S9.1]
JUNOS Online Documentation [18.1R3-S9.1]
JUNOS Kernel Software Suite [18.1R3-S9.1]
JUNOS Packet Forwarding Engine Support (qfx-ex-x86-32) [18.1R3-S9.1]
JUNOS Routing Software Suite [18.1R3-S9.1]
JUNOS jsd [i386-18.1R3-S9.1-jet-1]
JUNOS SDN Software Suite [18.1R3-S9.1]
JUNOS Enterprise Software Suite [18.1R3-S9.1]
JUNOS Web Management Platform Package [18.1R3-S9.1]
JUNOS py-base-i386 [18.1R3-S9.1]
JUNOS py-extensions-i386 [18.1R3-S9.1]
QFX Installation Software [18.4R2-S5.4]
JUNOS Host Software [18.1R3-S6.1]使用下列指令執行更新，指令最後面要改成自己的路徑及檔名：
KerKer@sw1> request system software add /var/tmp/jinstall-host-ex-4600-18.4R2-S5.4-signed.tgz 下了這條指令後就會開始執行韌體更新，更新完成後會有提視需要重新啟動，依提示內容執行下列指令：
KerKer@sw1> request system reboot at now重啟完成後再次確認版本：
KerKer@sw1> show version
fpc0:
--------------------------------------------------------------------------
Model: ex4600-40f
Junos: 18.4R2-S5.4
JUNOS Base OS boot [18.4R2-S5.4]
JUNOS Base OS Software Suite [18.4R2-S5.4]
JUNOS Crypto Software Suite [18.4R2-S5.4]
JUNOS Crypto Software Suite [18.4R2-S5.4]
JUNOS Online Documentation [18.4R2-S5.4]
JUNOS Kernel Software Suite [18.4R2-S5.4]
JUNOS Packet Forwarding Engine Support (qfx-ex-x86-32) [18.4R2-S5.4]
JUNOS jsd [i386-18.4R2-S5.4-jet-1]
JUNOS Routing Software Suite [18.4R2-S5.4]
JUNOS SDN Software Suite [18.4R2-S5.4]
JUNOS Enterprise Software Suite [18.4R2-S5.4]
JUNOS Web Management Platform Package [18.4R2-S5.4]
JUNOS Openconfig [18.4R2-S5.4]
JUNOS py-base-i386 [18.4R2-S5.4]
JUNOS py-extensions-i386 [18.4R2-S5.4]
JUNOS Host Software [18.1R3-S6.1]參考資料：https://www.juniper.net/documentation/en_US/junos/topics/topic-map/install-and-upgrade-firmware.html