Weired question - same DOT1Q tag on two interfaces on same

Folks,
Here is what I am trying to do.

all routers are 2911 or 2811 with routed interface (no switching module
ESW).

R1------------R2----------R3----------R4

Scenario1 - which I always implement:
-----------------------------------------
R1 - R2 = VLAN 10 - 10.10.10.1/30
R2 - R3 = VLAN 20 - 20.20.20.1/30
R3 - R4 = VLAN 30 - 30.30.30.1/30

Number of VLANs consumed in above scenario:
R1 = 1 i.e. fast0/0.10
R2 = 2 i.e. fast0/0.10 and fast0/1.20
r3 = 2 i.e. fast 0/0.20 and fast0/1.30
and so on......

To reduce the number of VLAN per router and keep the routing intact can we
do this?

Scenario#2
R1 - R2 = VLAN 10 - 10.10.10.1/30
R2 - R3 = VLAN 20 - 20.20.20.1/30
R3 - R4 = VLAN 30 - 30.30.30.1/30

Number of VLANs consumed in above scenario:
R1 = 1 i.e. fast0/0.10
R2 = 1 i.e. fast0/0.10 and fast0/1.10
r3 = 1 i.e. fast 0/0.10 and fast0/1.10
and so on......

Did you noticed in above case R2 and R3 are only using 2 VLAN ID.

I'd be interested to hear from you guys if you see any issue in there i.e.
using vlan id 10 on R2/R3 both fe0/0 and 0/1 interfaces.

Note; No briding, need routing and shoudl be able to use all IOS Feature.

The idea is in multi tented environment, we should be able to use vlan ID 10
for a CUSTOMER1 on all the routers. Having vlan10 on R1 and 20 on r2-r3 and
so on is a bit messy. This approach can also save number of vlan consumed
and can tanent more customers.

I went thr the Dot1q header but not sure how router treat this on
interfaces.
http://www.cisco.com/en/US/docs/ios/12_3t/12_3t4/feature/guide/gtunvlan.html

Anyone running this kind of single VLAN in a production environment?

-frog

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Received on Thu Apr 15 2010 - 01:05:51 ART