From: Chip Nielsen (chipn@intraworx.net)
Date: Wed Oct 01 2003 - 21:36:15 GMT-3
Sorry for the confusion.
Although this solution does not use "vlan dot1q tag native", I think it
would also be acceptable as a solution to this task.
The solution below prevents untagged traffic by not allowing vlan 999 on
the trunk. The command "switchport trunk native vlan 999" changes the
native vlan on the trunk, hence all of the ALLOWED VLANs would be
tagged. Remember, only the NATIVE vlan is untagged. Since the native
vlan has been changed from vlan 1 to vlan 999, traffic on vlan1 would be
tagged crossing the trunk because vlan 1 is no longer the native vlan.
Make sense?
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
ccie2be
Sent: Wednesday, October 01, 2003 5:27 PM
To: Group Study; asadovnikov
Subject: Re: 3550 reconciling requirement to solution
I'm sorry. I clicked "send" too soon and forgot to include the solution.
I
sent the solution right afterwards. And, in the solution, there's no
command like "dot1q tag native".
interface Port-channel1
switchport trunk encapsulation dot1q
switchport trunk native vlan 999
switchport trunk allowed vlan 1,10,20,30,40,55,70,100
switchport mode trunk
no ip address
interface FastEthernet0/23
switchport trunk encapsulation dot1q
switchport trunk native vlan 999
switchport trunk allowed vlan 1,10,20,30,40,55,70,100
switchport mode trunk
no ip address
udld enable
channel-group 1 mode on
!
interface FastEthernet0/24
switchport trunk encapsulation dot1q
switchport trunk native vlan 999
switchport trunk allowed vlan 1,10,20,30,40,55,70,100
switchport mode trunk
no ip address
udld enable
channel-group 1 mode on
----- Original Message -----
From: "asadovnikov" <asadovnikov@comcast.net>
To: "'ccie2be'" <ccie2be@nyc.rr.com>; "'Group Study'"
<ccielab@groupstudy.com>
Sent: Wednesday, October 01, 2003 6:59 PM
Subject: RE: 3550 reconciling requirement to solution
There is a command on 3550 ("dot1q tag native" or something alone this
lines) which will make 3550 to send frames on the native VLAN of dot1q
trunk
with the tug.
Best regards,
Alexei
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
ccie2be
Sent: Wednesday, October 01, 2003 6:30 PM
To: Group Study
Subject: 3550 reconciling requirement to solution
Hi,
2 3550's are connected back to back via Fa0/23 and 0/24 ports on both
Cat's.
The requirement is this:
Config the 2 interfaces (Fa0/23 and Fa0/24) connecting the 3550's to
appear
as 1 link to STP....
This link should allow all vlan's to travel across with their vlan ID
intact. You can not use Cisco's proprietary protocol to achieve this.
Every
packet that traverses the link must have the vlan ID, no exceptions.
I'm OK with everything except the last 2 words, "no exceptions". Since
we
can't use ISL, 802.1q has to be used, but that means packets in the
native
vlan aren't tagged and thus don't have a vlan ID. The solution is
below,
but I'm hoping someone can explain how that solution meets the above
requirement and maybe what would be a good way to think through this
problem.
Thanks, dt
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This archive was generated by hypermail 2.1.4 : Mon Nov 24 2003 - 07:52:55 GMT-3