Subinterface stop when I use vlan 1 default - Cisco ASA5520

[aporcaro01]

Hi there,

I´m trying to configure a subinterface named Inside with vlan 1 but the interface stops work with this vlan.

My switch is a Cisco and use the lan with vlan 1 too.

If I change de vlan for other i.e vlan13 works fine. And all others vlans works fine too.

Is there a problem to use the vlan 1?

My configuration is:

Cisco ASA:

interface gig0/3

no ip address

no security

no nameif

Interface gig0/3.1

vlan 1

nameif Inside

Securirity-level 100

ip address 10.x.y.x 255.255.224.0

The  giga port of the swtich is configure to trunk model;

Where the problem is?

Tks

Adriano Porcaro

[Somanna M.P]

Hi Adriano,

     As per my knowledge what is happenning here is that in the switch VLAN1 is the native vlan be default, unless you have changed it. Now when the switch passes native VLAN traffc it passes it untagged, which is not dot1q. Where as the subinterfaces on the ASA passes only dot1q traffic i.e anything other than the native VLAN on the switch. Please try to change the native VLAN on the switch and use the VLAN to pass traffic.

Hope this helps!

Regards,

Som

P.S : Please mark this post as resolved if it is answered. Do rate the helpful posts. Thanks.

[Somanna M.P]

     If you want to use Vlan1 you can assign an IP address to the physical interface and it will pass the untagged native VLAN traffic.

Hope this helps.

-Som

[amirali-arazm]

Dear All,

I had same problem with ASA 5512 and I managed to solve it by this: 

interface GigabitEthernet0/4
 nameif PM2
 security-level 100
 ip address 10.0.13.1 255.255.255.0
!
interface GigabitEthernet0/4.102
 vlan 102
 nameif PM2_GUEST
 security-level 100
 ip address 10.102.13.1 255.255.255.0
!

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