Beginning Tuesday July 11, 2006, access to the EECS caching DNS (Domain Name Server or Domain Name System) servers cronus and rhea will be restricted to campus IP addresses.
If you have a system off-campus, you will not be able to use cronus and rhea for DNS service. Instead you will need to configure your off-campus system to utilize your ISP’s name servers.
This action (restricting access to the EECS caching DNS servers) is occuring following the campus IS&T’s lead of restricting access to the main campus caching DNS servers, ns1.berkeley.edu (126.96.36.199, 188.8.131.52) and ns2.berkeley.edu (184.108.40.206, 220.127.116.11) beginning July 1, 2006.
It is currently considered a “best practice” to restrict access to caching DNS servers. DNS service on cronus and rhea has been abused from off-campus IP addresses. Because of the security risks associated with allowing anyone to access the caching DNS servers, many groups are restricting access to their caching DNS servers including UCLA, the University of Oregon and the University of Virginia.
IS&T has documented details and reasons behind why it is necessary to restrict access to caching DNS servers:
Current cronus and rhea IP addresses include:
cronus interfaces rhea interfaces cronus-32 18.104.22.168 rhea-32 22.214.171.124 cronus-33 126.96.36.199 rhea-33 188.8.131.52 cronus-34 184.108.40.206 rhea-34 220.127.116.11 cronus-35 18.104.22.168 rhea-35 22.214.171.124 cronus-36 126.96.36.199 rhea-36 188.8.131.52 cronus-37 184.108.40.206 rhea-37 220.127.116.11 cronus-38 18.104.22.168 rhea-38 22.214.171.124 cronus-40 126.96.36.199 rhea-40 188.8.131.52 cronus-41 184.108.40.206 rhea-41 220.127.116.11 cronus-42 18.104.22.168 rhea-42 22.214.171.124 cronus-43 126.96.36.199 rhea-43 188.8.131.52 cronus-47 184.108.40.206 rhea-47 220.127.116.11 cronus-48 18.104.22.168 rhea-48 22.214.171.124 cronus-62 126.96.36.199 rhea-62 188.8.131.52 cronus-63 184.108.40.206 rhea-63 220.127.116.11 cronus-112 18.104.22.168 rhea-112 22.214.171.124 cronus-132 126.96.36.199 rhea-132 188.8.131.52 cronus-134 184.108.40.206 rhea-134 220.127.116.11 cronus-153 18.104.22.168 rhea-153 22.214.171.124 cronus-168 126.96.36.199 rhea-168 188.8.131.52 cronus-171 184.108.40.206 rhea-171 220.127.116.11 cronus-cusg 18.104.22.168 rhea-cusg 22.214.171.124 cronus-169-229-63 126.96.36.199 rhea-169-229-63 188.8.131.52
Caching DNS service will also end from IP address 184.108.40.206 on Tuesday July 11, 2006.
Please update your off-campus systems accordingly.