Operation Manual – IPv4 RoutingH3C S7500E Series Ethernet Switches Chapter 4 IS-IS Configuration4-22To do… Use the command… RemarksEnable automatic IS-IScost calculation auto-cost enable RequiredDisabled by default.Note:In the case no interface cost is specified in interface view or system view and automaticcost calculation is enabled:z When the cost style is wide or wide-compatible, IS-IS automatically calculates theinterface cost based on the interface bandwidth, using the formula: interface cost =bandwidth reference value/interface bandwidth, and the maximum calculated cost is16777214.z When the cost style is narrow, narrow-compatible, or compatible, if the interfaceis a loopback interface, the cost value is 0; otherwise, the cost value is automaticallycalculated as follows: if the interface bandwidth is in the range of 1 M to 10 M, theinterface cost is 60; if the interface bandwidth is in the range of 11 M to 100 M, theinterface cost is 50; if the interface bandwidth is in the range of 101 M to 155 M, theinterface cost is 40; if the interface bandwidth is in the range of 156 M to 622 M, theinterface cost is 30; if the interface bandwidth is in the range of 623 M to 2500 M, theinterface cost is 20, and the default interface cost of 10 is used for any otherbandwidths.4.4.4 Configuring the Maximum Number of Equal Cost RoutesIf there are more than one equal cost routes to the same destination, the traffic can beload balanced to enhance efficiency.Follow these steps to configure the maximum number of equal cost routes:To do… Use the command… RemarksEnter system view system-view ––Enter IS-IS view isis [ process-id ] ––Specify the maximumnumber of equal costroutes for load balancingmaximumload-balancing numberOptionalThe default number is 4.4.4.5 Configuring IS-IS Route SummarizationThis task is to configure a summary route, so routes falling into the network range of thesummary route are summarized with one route for advertisement. Doing so can reduce
