ensait.fr

Delegation · all IPv4 addresses are in 193.48.37.0/24. A single network failure takes all nameservers down; RFC 2182 recommends topologically separate networks (anycast setups are an exception).

Delegation · None of the nameservers has an IPv6 address, so IPv6-only resolvers can't reach them.

Nameservers · These nameservers report their software version via version.bind/version.server, which helps attackers find known vulnerabilities: ns1.ensait.fr: "9.18.49-1~deb12u2-Debian"; ns2.ensait.fr: "9.18.47-1~deb12u1-Debian". Hide or replace the version string.

SOA · retry 1h should be shorter than refresh 1h; negative caching TTL (minimum) 3m is outside 5m–1d (RFC 2308 recommends 1–3 hours). Current values: refresh 1h, retry 1h, expire 14d, negative TTL 3m.

DNSSEC · The zone is not signed with DNSSEC, so answers can be spoofed. Enable DNSSEC at your DNS provider and publish the DS record at your registrar.

Records · These records have a TTL below 5m, causing extra queries and slower lookups: A (1m), MX (1m), NS (1m). Low TTLs are useful just before a planned change. The NS TTL at the parent is 1h and in the zone 1m; resolvers may use either.

DNSSEC · DNSSEC is not enabled for this domain. Consider enabling DNSSEC to protect against DNS spoofing attacks.

MX · The following MX hosts could not be resolved to IPv6 addresses: mx1.relay.renater.fr, mx2.relay.renater.fr

DKIM · 1024-bit RSA keys are the minimum and are considered weak today: mail (1024 bits). Rotate to a 2048-bit key.

TLS · MTA-STS is not configured, so other mail servers fall back to unencrypted delivery when TLS fails or is stripped by an attacker. Publish a _mta-sts TXT record and a policy at https://mta-sts.<domain>/.well-known/mta-sts.txt.