Help on matching two columns in excel having multiple numbers in once cell???

Please help on below matching task

Sheet1
old new
A1 B1
10.15.45.63 192.168.206.11
192.168.206.12
10.15.45.65 192.168.206.13
10.15.45.66 192.168.206.14
10.15.205.54 192.168.206.15
10.15.205.55 192.168.206.16

Sheet2
A1
10.14.45.29
(below is in one cell)
"10.15.45.65
10.15.45.66"

If A1 on sheet2 matches exactly with the A1 column on Sheet1, Print corresponding new ip at B1 at sheet2 and so on ( The challenge is on one cell in Sheet has multiple ips)