Why EIGRP Passive Interface is Required for Lan Networks ?
The EIGRP passive interface feature is used in LAN networks to prevent unnecessary routing updates from being sent to neighboring routers. By configuring an interface as passive, it will still receive routing updates but will not send them out. This helps to conserve network resources and ensures that routing information is not unnecessarily propagated to all routers in the network.
Because, EIGRP Passive interface help us to block the EIGRP packets to entering in Lan network. Passive Interface will receive the EIGRP packets but will not forward to Lan network. Due to this we save the bandwidth and router memory.
EIGRP passive interface is required to prevent Interfaces to send EIGRP messages on lan segment which are not participating in EIGRP process.
By implementing this we can also reduce unneccessary Bandwidth utilization in network.
To avoid traffic in user end
EIGRP passive interface is generally used to stop sending/receiving routing protocol packets (hellos, updates etc.) on that interface.
the passive-interface command stops both outgoing and incoming routing updates