To avoid overloading other servers (not necessarily your ISP) you can use our DNS servers:
ns1.cybercomplex.net
Location: Germany/Frankfurt
IPv4: 51.75.75.243
IPv6: 2001:41d0:701
ns2.cybercomplex.net
Location: Canada/Beauharnois
IPv4: 142.4.202.62
IPv6: 2607:5300:101:0:0:0:0:75d
ns3.cybercomplex.net
Location: Poland/Warsaw
IPv4: 80.211.250.127
IPv6: fe80::250:56ff:fea9:8da0
ns4.cybercomplex.net
Location: Australia/Sydney
IPv4: 139.99.170.90
IPv6: 2402
You can also set up your own DNS server (or just DNS cache) on your LAN.
This is especially important if you have several/many BOINC clients and CNode app.
You can check which of the above DNS will be the best (geolocation).
Source: https://root.ithena.net/usr/forum_thread.php?id=119