BIND
3 incident problems in BIND environments.
Read first
When DNS changed but some clients still hit the old backendAn InfraTree guide that lays out the first signals to check, the CLI verification order, common misdiagnoses, and a safe recovery path when the DNS record is updated but resolver cache, HTTP/2 keepalive, or client pools hold on to the old target.Network3 min readWhen firewalld looks open but connections keep getting blockedAn InfraTree guide that lays out the first signals to check, the CLI verification order, common misdiagnoses, and a safe recovery path when a port rule appears to exist but the connection fails because of zone, runtime/permanent drift, source binding, or an upstream firewall.Network3 min readHow to separate timeout and connection refused by network pathAn InfraTree guide that lays out the first signals to check, the CLI verification order, common misdiagnoses, and a safe recovery path when DNS, route, firewall, proxy, and listener states all look like the same connection failure.Network3 min read
Recommended problems
Reviewed problems first, then problems with detailed scenarios.
All problems (3)
NETWORK-1613A DNS server is reachable and one zone still failsOne zone still fails after changing a DNS forwarder.ReviewedNetworkBeginner6 minFreeNETWORK-1487A split-horizon DNS design is correct and one branch still resolves the public addressOnly one branch office keeps resolving the public endpoint after an internal split-horizon migration.NetworkIntermediate10 minProNETWORK-1619A resolver update is correct and one site still gets stale answersOne site still gets stale DNS answers after a resolver update.NetworkIntermediate9 minPro