dnsmasq slow dns

Все работало до недавнего времени замечтально.
Стоит ubuntu server, раздает интернет. Вчера появились дикие тормоза в определении имен хостов у клиентов:

C:\Windows\System32>nslookup rutor.org
DNS request timed out.
    timeout was 2 seconds.
╤хЁтхЁ:  UnKnown
Address:  192.168.2.1

DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
*** Превышено время ожидания запроса UnKnown

DNS request timed out.
    timeout was 2 seconds.
*** Request to UnKnown timed-out

на самом сервере все отлично:
root@ubuntu:/etc# nslookup rutor.org
Server:         109.194.96.1
Address:        109.194.96.1#53

Non-authoritative answer:
Name:   rutor.org
Address: 186.2.161.82

Что случилось с днс у клиентов?