感謝大神，範例做完，大概知道麼設定了^^

###########################################################################
型號：dell switch n2048
同一台Switch 48 port 分3個VLAN，第port 1連到外網，各個VLAN之間不能互通，但可全透過port 1.2.3(vlan1)上網
vlan 1：port 1-3，(pvid：1，untagged vid：1-3)
valn 2：port 4-30，(pvid：2，untagged vid：1,2)
valn 3：port 31-28，(pvid：3，untagged vid：1,3)

################
interface range gigabitethernet 2/0/1-3
switchport mode general
switchport access vlan1
switchport general pvid 1
switchport general allowed vlan add 1-3 untagged
no shutdown
exit

################
interface range gigabitethernet 2/0/4-30
switchport mode general
switchport access vlan2
switchport general pvid 2
switchport general allowed vlan add 1,2 untagged
no shutdown
exit

################
interface range gigabitethernet 2/0/31-48
switchport mode general
switchport access vlan3
switchport general pvid 3
switchport general allowed vlan add 1,3 untagged
no shutdown
exit

################
show interfaces switchport gigabitethernet 2/0/2
Access Mode VLAN: 1，General Mode PVID: 1，General Mode Untagged VLANs: 1-3

show interfaces switchport gigabitethernet 2/0/20
Access Mode VLAN: 2，General Mode PVID: 2，General Mode Untagged VLANs: 1-2

show interfaces switchport gigabitethernet 2/0/40
Access Mode VLAN: 3，General Mode PVID: 3，General Mode Untagged VLANs: 1,3

################
show vlan
VLAN Name Ports Type

1 default Po1-128, Default
Gi2/0/1-48,
Te2/0/1-2
2 VLAN0002 Gi2/0/1-30 Static
3 VLAN0003 Gi2/0/1-3, Static
Gi2/0/31-48
################
##測試
port 1-3 可連上外網，(vlan1)
測試：port 3、20、40，(ping 8.8.8.8全部vlan、port都可以連上外網)
測試：port2、3，port35、45，(同vlan互ping可以通)
測試：port2、45，(vlan1 ping vlan5通)
測試：port10、40，(vlan2 ping vlan3不通)

192.168.2.79、192.168.2.171互ping

################
##參考連結：
https://ithelp.ithome.com.tw/questions/10193940#answer-356128
https://ethernet-diy.blogspot.com/2017/11/8021q-tag-vlan-l2l2.html
https://weihanit.wordpress.com/2017/07/27/switch-vlan%E8%A8%AD%E5%AE%9A%E7%AF%84%E4%BE%8B%E4%B8%80/
https://www.dell.com/support/article/tw/zh/twbsd1/how12148/how-to-configure-switchport-modes-on-dell-networking-n-series-switches?lang=en
###########################################################################