Encapsulation dot1q

[ghtmoha153]

I have router 2921 with 3 layer 3 interfaces i need to configure one of them as access interface encapsulation in bidirectional (not subinterface solutions)

[marce1000]

 - The question is confusing , layer 3 interface, can not be access ports ,

 M.

[ghtmoha153]

.

[ghtmoha153]

My question is layer3  interface can encapsulation packets and send it out from router or no t

[MHM Cisco World]

in the router and in SW must not use native vlan, native vlan is send untag frame
for config you need 
in SW config trunk and allow vlan <vlan id>
and in Router config subinterface with encapsulation dot1q <vlan id>

[ghtmoha153]

In my case i want to configure two interfaces in same router one is physical and second one is subinterface with vlan 3090 in another physical interface and physical one i need connect it to end device 

[MHM Cisco World]

sorry can you more elaborate more?
router interface f0/0 without subinterface 
router interface f0/1 with subinterface 
and then what?

[ghtmoha153]

 So in R1 i configure bridge group (interface fa0/0 and fa0/1.3090)  fa0/0 is connected to switch 3750 with vlan 1 

Fa0/1.3090 connect to sw 3750 with vlan 3090 i do ping between int vlan 3090 and int vlan 1 so no reply what can i do to connect vlan 1 and 3090

[MHM Cisco World]

R1
bridge irb
bridge-group 1
!
interface FastEthernet2/0.999
encapsulation dot1Q 999
bridge-group 1
!
interface BVI1
ip address 10.0.0.10 255.255.255.0
!
bridge 1 protocol ieee
bridge 1 route ip

IOU1
interface Vlan1
ip address 10.0.0.1 255.255.255.0
no ip route-cache
!
ip default-gateway 10.0.0.10

IOU2
interface Vlan999
ip address 10.0.0.2 255.255.255.0
no ip route-cache
!
ip default-gateway 10.0.0.10
!
interface Ethernet2/0
switchport trunk allowed vlan 999
switchport trunk encapsulation dot1q
switchport mode trunk

[paul driver]

Hello

---

@ghtmoha153 wrote:

My question is layer3  interface can encapsulation packets and send it out from router or no t

---

Yes it can.
The physical port of the interface will connect to the switch at layer 2 and then the logical sub-interfaces provids the Layer 3 addressing that relates to the specific vlan ids using dot1q trunking.

By default if you use the parent physical interface as L3 also then this is the native vlan 1

example:
int x/x
description vlan 1
ip address 10.1.1.1 255.255.255.0

or

int x/x

int x/x.1
description vlan 1
encapsulation dot1q 1 native
ip address 10.1.1.1 255.255.255.0

 
int x/x.2
description vlan 2
encapsulation dot1q 2
ip address 10.1.2.1 255.255.255.0

int x/x.3
description vlan 3
encapsulation dot1q 3
ip address 10.1.3.1 255.255.255.0