trunk and layer 3 connectivity

[david_kamal2000@yahoo.com]

Hi,

i have core switch connected to firewall

the interface in core configuration is 

interface Ethernet103/1/24
description PA-VM2 -VSwitch2
switchport
switchport mode trunk
no shutdown

interface Vlan3
no ip redirects
ip address 10.153.16.9/21
description Gateway_Of_Server_Zone
no shutdown

and from fw it is untagged interface L3 with ip 10.153.16.8

is that is possible? how they communicate in the switch port is not layer 3?

should it be 

interface Vlan3
no ip redirects
ip address 10.153.16.9/21
description Gateway_Of_Server_Zone
no shutdown

?????

[AndreaTornaghi · Accepted solution]

Dear,

you should add on the switch interface connected to fw this config:

#switchport trunk native vlan 3

Otherwise you should configure the switch port connected to fw  in access on vlan 3.

If you do vlan tagging on one side you should use the same tag on the other side. Otherwise if you use only one vlan you can use untagged vlan and configure the switch port in access mode.