Datagram forwarding. Give

forwarding tables for switches S$1,$

S$2,$ S$3,$ and S$4.$ Each switch

should have a $$default$$ routing

entry, chosen to forward packets

with unrecognized destination

addresses toward OUT. Any

specific$-$destination table entries duplicated by the default entry should then be eliminated from the

S$1$

$31$

$2$

S$2$

$31$

C

$2$

S$3$

$31$

D

$2$

S$4$

host switch

tables.