Non-equivalent routing load of IGRP and OSPF

IGRP, the Load Balancing of the non-equivalent routing Load of the network in the network. In addition, IGRP and MongoDB also support load balancing with unequal paths and use the variance command. The Variance command advertises a n value to the router, and the n value is specified using the variance command. The value of n is 1-. The default value is 1. www.2cto.com network topology Variance for example, router E has three paths to the network X E-B-A with a metric of 30 E-C-A with a metric of 20 E-D-A with a metric of 45 Router E select the second path, metric for the E-C-A is 20, 20 is the minimum value for three paths, and if you want to select a preferred E-B-A path, configure the variance value as multiplier 2
In this way, metric is increased to 40 (2*20 = 40 ). In this way, VPN includes all the routes with metric less than 40. In the preceding configuration, the router uses two paths to reach network X, E-C-A, and E-B-A, because both paths have metric values below 40. Because the E-D-A's metric is 45, greater than 40, it is not selected for this path to reach network X. in addition, vrod D reports that the metric that reaches network X is 25, which is larger than the metric value of the line. This means that even if variance is set to 3, the E-D-A path will not be selected as the Server Load balancer path because router D is not a viable successor. Traffic Sharing www.2cto.com network not only supports load balancing with unequal paths, but also supports intelligent load balancing, such as traffic sharing. when multiple routes arrive at the same destination network with different cost, you can use the traffic sharing command to control the traffic on different routes. Using the balanced keyword, The vro distributes traffic proportionally according to the metrics ratio of different routes. This is the default setting of router VPN 1 network x. x variance 2 traffic-share balanced
The following is the traffic share computing case For path E-C-A: 30/20 = 3/2 = 1 For path E-B-A: 30/30 = 1 if not divisible, we calculate according to its INTEGER (Note: Not rounding ). In this case, the ratio of the E-C-A to the E-B-A of the packet sent by the kernel is, which achieves the purpose of load balancing. Now we assume that the metric between the E-B is 25, and the metric between the B-A is 15. this way the metric of the E-B-A is 40 because 40 is not less than 2x20 (20 is the viable path metric, 2 is the variance value), So load balancing is not possible between the E-C-A and the E-B-A. To achieve load balancing, we need to set the variance value to 3. so the traffic share ratio on the two links is www.2cto.com For path E-C-A: 40/20 = 2 For path E-B-A: 40/40 = 1 so that the traffic ratio of the VPN in the E-C-A and E-B-A is. by using this method, not only does it support non-equivalent routing load balancing, but it also supports intelligent load balancing.
When using the keyword min, traffic is sent only through the minimum cost path, even if there are multiple route paths in the route table router VPN 1 www.2cto.com network x. x. x. x variance 3 traffic-share min shares SS-interfaces results in that the article is also applicable to igrp only through the path of the E-C-A