In which way are EIGRP and OSPF similar?

EIGRP supports autosummarization by default (though often disabled), which summarizes routes at major network boundaries, whereas OSPF does not support autosummarization; its summarization is configured manually within ABRs and ASBRs.

Both EIGRP and OSPF send periodic hello packets out of interfaces to dynamically discover other routers running the same protocol on the segment and establish and maintain adjacency or neighbor relationships. These hellos also ensure that neighbors are still alive.

EIGRP supports unequal-cost load balancing through its variance command, allowing traffic to be distributed across paths with different metrics, while OSPF only supports equal-cost load balancing.

EIGRP sends updates using a multicast address (224.0.0.10) for discoveries and updates (reliable multicast), and OSPF sends updates primarily via multicast addresses (224.0.0.5 for all OSPF routers, 224.0.0.6 for DRs/BDRs), not unicast for all updates.