Sites were banned using a combination of DNS blocking and IP blocking. DNS blocking is relatively easy to circumvent (whether implemented through ISP-controlled DNS servers or sniffing all DNS requests); whereas IP bans can only be circumvented with a proxy, VPN or Tor. Information on the exact methods and timeframes that sites were blocked is vague and anecdotal, but there was a significant amount of online discussion at the time. Optus appeared to use IP blocks for 4chan and possibly other sites. Telstra took a similar approach. Most bans appeared to be lifted after several weeks, with 4chan and Voat bans extending longer. One source states that the Telstra bans lasted only "a few hours", but this does not agree with most online discussion.