Merhabalar, sunucuya mono paketini kurarken hata alıyorum. Sebebi ne olabilir, bilgisi olan var mıdır?

Download - Stable | Mono (mono-project.com)

Kod: rpmkeys --import "http://pool.sks-keyservers.net/pks/lookup?op=get&search=0x3fa7e0328081bff6a14da29aa6a 19b38d3d831ef"

Hata:
curl: (6) Could not resolve host: pool.sks-keyservers.net; Unknown error
error: http://pool.sks-keyservers.net/pks/l...19b38d3d831ef: import read failed(2).