So I'm not sure where to start with this one, any pointers would be 
appreciated.  I'd be happy to google but I'm not sure what the condition is 
here at all, I'm pretty baffled.

Here's the setup.

A Single 7200 with an NPE400 and a few fast E interfaces.  I have two metro 
Ethernet pretty standard connections terminated on fast 1/0 and fast 3/0.  Each 
has trunking enabled and different VLAN tags on each although they share 
destinations in common.  Our colocation on VLAN 600 on fast 1/0 for example 
would be 800 on fast 3/0.  There's no overlap in VLAN tags.  On each is 
attached a /30.  So the config looks something like this.

int fast 1/0
no ip address
no ip proxy arp
no ip directed broadcast
speed 100
duplex full

int fast 1/0.600
encapsulation dot1q 600
ip address 192.168.1.1/30
desc colo

(and so on)
both the same on each interface with the same type of setup just with different 
tags.

Ok, the problem.

If I bring up link 2 on fast 3/0 all the traffic moves in the outbound 
direction from fast 1/0 to 3/0 until 1/0 finally settles at 0 bits per second.  
No matter whether I play with the routing weights or preferences the traffic 
still prefers the second interface.  To be honest, I don't even know how 
traffic on 1/0 would even arrive on 3/0.  This happens even if I shut down the 
individual sub interfaces, leave only the interface itself up and disable all 
the routing protocols by hand bound to each neighbor address.  What gives?  
Obviously something on layer 2 is going squarely  but with the sub interfaces 
disabled I don't understand how my traffic redirecting and stranger still 
arriving at the far end.  What am I missing, I'm quite confused!  I'm guessing 
something on the carrier providing the Metro E but I'm not sure where to start 
diagnosing this issue.  Any ideas would be appreciated.

Thanks
Scott


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