Let me spell this out in really simple terms.
Www.invisionpower.com has one IP number (**.**.**.**2), which is the same as for invisionpower.com, via cname, but the reverse is corp01.lw.ipslink.com.
Community.invisionpower.com has one IP number (**.**.**.**7), but the reverse is community.lw.ipslink.com.
Notice that the redacted IP addresses end in different numbers and their reverse is a different host name. That second IP the one is under attack and they are filtering traffic which causes this domain to time out. Untill the attack stops, or they white list your IP Address (if they are even whitelisting), if you move around this site too fast the mitigation rules are going to drop your connection.