router - Why not use MAC addresses instead of Local IPs? -

router - Why not use MAC addresses instead of Local IPs? -

in similar questions, question has been answered is:

why need both mac , ip addresses on internet? both addresses. why can't 1 used describe device?

the reply along lines of:

the 2 protocols not universal, not devices utilize it. ip provides logical address , allows routing, mac doesn't back upwards routing, , more.

my new question is:

that's nice reply why net whole needs both types of addresses, why need local ip addresses?

locally, on same network, no routing involved, i'm sending computer next me. why can't send straight mac address? , router connects our local network net - why can't store table of mac addresses maintain track of outside world goes in "local world"?

the existence of local ip seems unnecessary.

so lets forget sec modern os's based on ip/ipv6 , suggestion break everything. imagine analogy:

an ip address qualified postal address:

i. m. ray 1024 megabit dr somecity, state 10101

your mac address physical house. bluish 1 4 house corner, big oak tree.

when sending letter conventionally, mail service routed local post office based on total address. compare routing of ip on internet. post office mail service sent care less oak tree.

in conventional method, post man organize deliveries street, , go house house delivering mail. similar arp table, have organized houses easy find , navigate index.

in proposed method, mail service arrives @ post office, replace envelope total address 1 description of house on it. post mans job remember bluish house oak tree is.

so, while thoughts on right track, not practical. 1 time on same layer 2 domain (local), don't need routing , in theory utilize physical addresses.

i sorry if pretty far out answer. i've been reading other questions on topic, , seems though trying wrap head around subject, , best effort @ breaking downwards logically. whole thought pretty tricky understand @ first (we've been there), 1 time figure out parts , role play in grand scheme, more starts create sense.

please sense free inquire if have questions, primary intention of posting help out.

ip router mac-address local-network