Locate the systemd file of that service:
pico /usr/lib/systemd/system/grafana-server
Add this 2 lines at service
[Service]
…
…
AmbientCapabilities = CAP_NET_BIND_SERVICE
CapabilityBoundingSet = CAP_NET_BIND_SERVICE
Run:
systemctl daemon-reload
Restart service
DFSR Firewall ports
ICMP Echo
Port 53 DNS TCP and UDP
Port 88 LDAP TCP and UDP
Port 135 Netbios TCP
Port 139 Netbios TCP
Port 138 NTP TCP and UDP
Port 123 time
Port 455 Kerberos TCP
Port 389 LDAP SSL TCPP
Port 636 Microsoft DFS TCP
Port 5722 Microsoft DFSR TCP
Port 49154 Netbios TCP and UDP
Port 49155 Active Directory Trust Policy TCP
Port 49158 CFS TCP and UDP