Hola Carlos Te falta la resolución de localhost en el propio DNS.
Paso la salida total del host -v localhost a ver si ves algo raro, porque yo no lo veo, (no controlo demasiado la salida de este comando) host -v localhost Trying "localhost.dominio.com" Trying "localhost" ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 16786 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 1, ADDITIONAL: 0 ;; QUESTION SECTION: ;localhost. IN A ;; ANSWER SECTION: localhost. 604800 IN A 127.0.0.1 ;; AUTHORITY SECTION: localhost. 604800 IN NS localhost. Received 57 bytes from 192.168.1.205#53 in 0 ms Trying "localhost" ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 9224 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0 ;; QUESTION SECTION: ;localhost. IN AAAA ;; AUTHORITY SECTION: localhost. 604800 IN SOA localhost. root.localhost. 42 172800 14400 3628800 604800 Received 68 bytes from 192.168.1.205#53 in 0 ms Trying "localhost" ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 53998 ;; flags: qr aa rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0 ;; QUESTION SECTION: ;localhost. IN MX ;; AUTHORITY SECTION: localhost. 604800 IN SOA localhost. root.localhost. 42 172800 14400 3628800 604800 Received 68 bytes from 192.168.1.205#53 in 0 ms ¿Ves algo raro? Emi