You should see most of our requests from theses guys (used for fetching and parsing):

superparsr21		 173.255.194.171	 
superparsr22		 173.255.194.52	 
superparsr23		 173.255.194.53	 
superparsr24		 173.255.194.65	 
superparsr25		 173.255.194.66	 
superparsr26		 173.255.194.67	 
superparsr27		 173.255.195.112	 
superparsr28		 173.255.195.113	 
superparsr29		 173.255.195.114	 
superparsr30		 173.255.195.115	 
superparsr31		 173.255.195.183	 
superparsr32		 173.255.195.184	 
superparsr33		 173.255.195.185	 
superparsr34		 173.255.195.188	 
superparsr35		 173.255.195.189	 
superparsr36		 173.255.195.201	 
superparsr37		 173.255.195.202	 
superparsr38		 173.255.195.203	 
superparsr39		 173.255.195.204	 
superparsr40		 173.255.195.206	 

Please remember that we can add or remove IPs to this list at any time, as we mostly use cloud services. Do not implement any blocking or limitation based on this list.