Why are IPV6 DNS lookups done even when IPV6 is disabled in Red Hat Enterprise Linux?
Issue
- Applications like ssh and telnet use the
getaddrinfo()
function withAF_UNSPEC
and this function invokes both AAAA (IPv6) and A (IPv4) lookups one after the other. This can delay the connection time when DNS servers block or don't handle IPV6 correctly.
Environment
- Red Hat Enterprise Linux 4
- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- glibc
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