EIGRP Unequal Load Balance

[Othacon]

Hi everyone,

hope you can help with EIGRP unequal load balancing in a Catalyst 3650. 

I have a system where I need to send the traffic to reach the 10.1.40.0/24 via the vlans 4084 and vlan 4087. Due to the metric, the vlan 4084 as the lowest FD and vlan 4087 is not installed in the routing table, not appearing even as a feasible successor. Tried to use the variance command but since the route doesn't appear in the EIGRP topology it didn't work. But if I do "show ip eigrp topology secondary-paths" the route appears there as per below: 

Neighbours

Show ip eigrp topology

show ip eigrp topology secondary-paths

I need to force the traffic to go via vlan 4084 and vlan 4087 alike in order to load balance the links, since I have one link that is being overloaded. Please could you help me with this?

Thank you

[Joseph W. Doherty]

"Well, after reading you post @Joseph W. Doherty , remembered to check if the switches had configured the "qos queue-softmax-multiplier" config. I've applied my policy map to the interface but assumed that this option was already enabled... it wasn't. Have now configured this and I'm forwarding now the packets to that link without packet drops."

Exactly the kind of configuration change I had in mind!  Your packet drop improvement often a common result.

It's often not just a short term fix as it often better leverages what you have, now, and in the future.

[Othacon]

@MHM Cisco World at the moment I don't have asymmetric traffic running in the network. I was able to solve all my drops

 by disabling Vlan 4084. I'm forcing now all the traffic to enter via the right side of the network and the left side. By doing this the packet loss was solved. The only thing is I loose the middle link, but I don't know until what point I will need it. I want it only to use it has a redundant path really. 

The idea is to bring all links online but maybe instead of using asymmetric traffic to force eigrp to send the traffic via vlan 4087 instead of vlan 4084. Maybe this option is better than asymmetric traffic. In essence I'm doing this as we speak, but i had to physically shut down the interface. 

The link (Gi1/0/24 (UPLINK) on ASW is showing:

this was before changing the route. I cleaned the counters as well 

[MHM Cisco World]

if the drop is stop then the issue was asymmetric not bottleneck 
the traffic now pass via VLAN4087 and via 1 gbps and there is no drop. 
MHM

[Othacon]

I may be wrong, but I don't think so @MHM Cisco World , because what EIGRP was doing, in essence was this:

All the traffic of 6 sites was being funneled to the ASW from CSW 2 and then down a 1Gbps pipe to the Main CSW from the ASW. The Link from CSW1 to CSW3 was a secondary path for EIGRP, and no traffic was being sent via that link from CSW 1, all the traffic was going to CSW2. By shutting down the link from CSW1 to CSW2, I forcibly load balanced the system for the data from the 6 sites to enter not only via the ASW but also via the other side of the network:

This way the data is being balanced out, some data enters via the ASW and another half of the data passes via CSW 3 and downstream entering straight in the main CSW via also a 1Gbps link. This reduced the load on the ASW bu ended up increasing the load on the CSW3 and consequently downstream. But because this links were underutilized, everything ended up even itself out.