ville-boulogne-sur-mer.fr

Delegation · all IPv4 addresses are in 62.193.51.0/24. 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: ns500013.as16211.net: "9.11.5-P4-5.1+deb10u5-Debian"; ns500014.as16211.net: "9.11.5-P4-5.1+deb10u5-Debian". Hide or replace the version string.

SOA · negative caching TTL (minimum) 2d is outside 5m–1d (RFC 2308 recommends 1–3 hours). Current values: refresh 1d, retry 2h, expire 1000h, negative TTL 2d.

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 (4m), MX (4m), NS (4m). Low TTLs are useful just before a planned change. The NS TTL at the parent is 1h and in the zone 4m; 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: mailhost.ville-boulogne-sur-mer.fr

MX · Only one MX record found. For better email reliability, consider adding at least one backup MX server.

DKIM · 1024-bit RSA keys are the minimum and are considered weak today: mail (1024 bits), s1 (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.