| Previous | Next |
| EINPROGRESS | EISCONN |
EHOSTUNREACH
EHOSTUNREACH is more specific than a general absence of a network route: the stack has determined that the particular destination host is unreachable. It can arise from local route policy, neighbor resolution, or network feedback. The code should not be interpreted as proof that the machine is powered off; packet filtering, a broken next hop, an incorrect address, or an IPv4/IPv6 mismatch can lead to the same application-visible result.
Linux documents an unreachable route type that returns EHOSTUNREACH to local senders and generates ICMP host-unreachable feedback. RFC 792 likewise distinguishes host-unreachable from network-unreachable in ICMP. The mapping and timing vary by system and protocol, so capture the actual destination address rather than relying on a hostname alone.
Useful investigation steps
- Verify DNS results and test each returned address family separately.
- Inspect the route, selected source address, gateway reachability, and ARP or NDP state on the local network.
- Check security groups, host firewalls, tunnel routes, and container or VPN namespaces.
- Use network traces when the application must distinguish a local policy route from a remote ICMP report.
Linux ip-route(8) · RFC 792: host unreachable · BSD errno descriptions
Looking for a different code? Search another status or error code.