Re: [LARTC] urgent TEQL problem

["Taylor, Grant" <gtaylor@riverviewtech.net>]

Based on your previous email and this email I see a couple problems with your situation.

1)  Your ""Gateway will not be able to ""route correctly between two interfaces on the same subnet.
2)  Node1 is ARPing out eth1 to try to find 16.119.114.66 on it's local subnet as it should be there but it is not as it is on the other side of a gateway.

If you do not want to do this on layer 2 and turn your gateway in to a bridge I think you will have to do all of this on layer 3 and route *BOTH* sides of teql0, how to do this I'm not sure of at the moment.  I have a feeling you will need to ultimately try to reach an IP that is not on any of your physical network cards but rather something on a dummy interface that is accessible via a route using either interface to get to.  I'll try to describe such a setup below.

Node 1:
- eth0:  <subnet 1>.1
- eth1:  <subnet 2>.1
- teql0: <subnet ?>.1
- dumy0: <subnet 3>.1

Node 2:
- eth0:  <subnet 1>.2
- eth1:  <subnet 4>.2
- teql0: <subnet ?>.2
- dump0: <subnet 5>.2

Gateway:
- eth0:  <subnet 2>.254
- eth1:  <subnet 4>.254

(Sitting her looking at this I'm not entirely sure that you even need teql0 but rather ECMP routing.)

Node 1 routing table:
<subnet 3> via <subnet 1>.2   metric 2
<subnet 3> via <subnet 2>.254 metric 1

Node 2 routing table:
<subnet 5> via <subnet 1>.1   metric 2
<subnet 5> via <subnet 4>.254 metric 1

Gateway routing table:
<subnet 3> via <subnet 2>.1 metric 1
<subnet 5> via <subnet 4>.2 metric 1

This *SHOULD* (if I have things correct in my head) establish two routes from <subnet 3> to <subnet 5> with the same overall metric of 2.  However to use ECMP you will need the metrics for both routes from <subnet 3 or 5> to <subnet 5 or 3> to be the same on Node 1 and Node 2.  Thus I might modify the routing tables as such.

Node 1 routing table:
<subnet 3> via <subnet 1>.2   metric 2
<subnet 3> via <subnet 2>.254 metric 2

Node 2 routing table:
<subnet 5> via <subnet 1>.1   metric 2
<subnet 5> via <subnet 4>.254 metric 2

Gateway routing table:
<subnet 3> via <subnet 2>.1 metric 0
<subnet 5> via <subnet 4>.2 metric 0

As my pager goes off I realize that I have to submit a partial post back to the list, but hopefully there is enough here to get a couple of points across and enough for someone else to work with to help flesh out this idea.



Grant. . . .

Li, Ji wrote:
> One more thing to add is that when I "ping 16.119.144.66" from Node1
> (16.119.144.66 is the teql0 of Node2), all messages I saw from
> Node1.eth1 are ARP messages "Who has 16.119.144.66? Tell 16.119.144.33".
> 
> Thanks,
> -Ji
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