内部网关路由协议（英语：Interior Gateway Routing Protocol，缩写为IGRP），又译闸道间选径协定，是一种内部网关协议，采用距离矢量算法。以自治系统 （Autonomous System）的方式提供路由选择路由协议，由思科系统公司发展而成的专利协议。其算法与路由信息协议（RIP）类似，透过用户配置，如延迟、带宽、可靠性及负载量等于各路由器进行的路由管理。

Interior Gateway Routing Protocol (IGRP) is a distance vector interior routing protocol (IGP) developed by Cisco. It is used by routers to exchange routing data within an autonomous system.

IGRP is a proprietary protocol. IGRP was created in part to overcome the limitations of RIP (maximum hop count of only 15, and a single routing metric) when used within large networks. IGRP supports multiple metrics for each route, including bandwidth, delay, load, and reliability; to compare two routes these metrics are combined together into a single metric, using a formula which can be adjusted through the use of pre-set constants. By default, the IGRP composite metric is a sum of the segment delays and the lowest segment bandwidth. The maximum configurable hop count of IGRP-routed packets is 255 (default 100), and routing updates are broadcast every 90 seconds (by default). IGRP uses protocol number 9 for communication.