In FQDN and Domain Objects in R80.10, if DNS server fails for DNS query it will affect the overall operation of checkpoint firewall? I remember that on R77, it will be affect if fail DNS query, the below rule will be fail too.
No it won't as DNS queries are executed in the background and cached every 30 seconds. I'm guessing in case you have a total DNS outrage for long period of time, DNS cache will last for each records TTL and then simply will time out and that rule simply won't work. But it won't affect other rules nor slow down the gateway
I believe it's one of the best hidden gems in R80.10!
More in Domain Objects in R80.10 and above
Adding to above answer..in R80.10 secure XL templates will be applied for Domain rules So there is no more performance impact with Domain rules on R80.10 gateways, being said that we can even write them on top of the rule base.
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