connection timed out; no servers could be reached

[JanuBari]

Is there an instance that fortinet blocks nslookup to certain servers?

We have a situation where we can do nslookup to certain dns servers but to others not.

The nslookup error is "connection timed out; no servers could be reached"

From the network without fortinet firewalls nslookup is fine. But from network with fortinet firewalls not all dns server can be reached for dns resolution.

[ShanWill]

First thing I would check is if you have firewall policies set appropriately to allow traffic to those destinations since there is an implicit deny all