ib.adnxs.com is an alias for g.geo.appnexusgslb.net.
g.geo.appnexusgslb.net is an alias for ib.anycast.adnxs.com.
ib.anycast.adnxs.com has address 37.252.172.123
ib.anycast.adnxs.com has address 37.252.171.52
ib.anycast.adnxs.com has address 37.252.173.215
ib.anycast.adnxs.com has address 37.252.171.53
ib.anycast.adnxs.com has address 37.252.171.149
ib.anycast.adnxs.com has address 37.252.171.85
ib.anycast.adnxs.com has address 37.252.171.21