EIGRP tags routes learned from IGRP or any outside source as external because they did not originate from EIGRP routers. IGRP cannot differentiate between internal and external routes.

• EIGRP标记从IGRP学来的路径或者任何不是发自EIGRP路由器的来源为外部的。IGRP则不能区分内部和外部路径。