(Windows)
nslookup whoami.ultradns.net
nslookup whoami.ultradns.net. <authoritative NS>
nslookup <Directional Pool Name.>
nslookup <Directional Pool Name.> <authoritative NS>
nslookup whereami.ultrasupport.info. <authoritative NS>
nslookup whereami.ultrasupport.info.
tracert <authoritative NS1>
tracert <authoritative NS2>
OR
(OSX/Unix)
dig whoami.ultradns.net
dig whoami.ultradns.net @<authoritative NS>
dig <Directional Pool Name>
dig <Directional Pool Name> @<authoritative NS>
dig whereami.ultrasupport.info <authoritative NS>
dig whereami.ultrasupport.info
traceroute <authoritative NS1>
traceroute <authoritative NS2>
AND
What is affected user's source/external IP? (https://www.google.com/search?q=what+is+my+ip)