At a site, the MAN contains 7 NE5000Es at the same layer, and they connect with two NE5000Es at egress at upstream. The two layers use both 2.5G and 10G links in the networking; at the same time, OSPF uses two 2.5G links and one 10G link to balance the traffice, but the bandwidth utilization of two 2.5G links reaches 80% quickly, and only2G of the 10G link bandwidth is engaged. The traffic over three links is not even.
Replace the 2.5G link with 10G for load balance.
OSPF realizes equal cost route according to the COST of links, not the bandwidth, so the routes corresponded to the three links are equal in cost. As a result, the traffic is distributed averagely, and the 2.5G link can reach its peak very quickly, but 10G link is used a small part.
In network planning, pay attention to if different links are used for load balance; if required to use the links of different bandwidth, active/standby mode is recommended. If load balance is required, configure ACL to adjust the route of the network segment with large traffic to the link with sufficient bandwidth, but this brings a certain risks. Althernatively, add some links with a lower bandwidth. The optimal is to configure the links for load balance with the same bandwidth.