bash-2.05$ host 213.177.117.154
154.117.177.213.IN-ADDR.ARPA domain name pointer idnp.ru
154.117.177.213.IN-ADDR.ARPA domain name pointer gmi.ru
154.117.177.213.IN-ADDR.ARPA domain name pointer KCNN.mts-nn.ru
bash-2.05$ host 80.21.158.233
233.158.21.80.IN-ADDR.ARPA domain name pointer host233-158.pool8021.interbusiness.it
bash-2.05$