Here is DNS request relay question. Please see the picture. R3 and R4 are DNS server, R1 is DNS client, which point to R3 as its DNS server. My question is if R3 cannot meet R1 DNS request, how can we configure R3
in order that R3 transfer the request to R4 ? In R3, I used the command "ip name-server 18.104.22.168(R4 ip address)", which points at R4, but it does not work. Thank you.