Nsa 3650 and access rules
Hi, i have a doubt about Access rules on our Sonicwall cluster: i basically want to block all LAN>WAN traffic and make explicit allow rules for each internal network to be "whitelisted". This is the scenario:
- The routing of internal networks is performed by core switches, and we have a "transport" network between them and firewalls. The "transport" sub interface that is dedicated to this is in the LAN zone
- In the access list "LAN>WAN" i performed the following operations:
- Created a "Deny all" rule with priority 263 (bottom one)that basically blocks everything
- Created specific rules (one for each network) that allows the LAN>WAN traffic changing the source network objects with the appropriate ones.
This should be very simple but i see that if i disable a specific allow rule for a network (and theoretically this would result belonging to the "Deny all" rule) the traffic still flows, but if i enable the rule and change the action from "allow" to "deny" the traffic is effectively blocked.
Example: if i take the network "INT_SERVER" dedicated to our virtual servers and disable the relative allow rule they still can reach internet, but if i change the rule to "block" traffic is effectively blocked.
Seems that somehow the final "Deny all" rule is ignored, and only creating specific deny rule for each network can achieve what i'm looking for.
Any tips on this?
Thank you!
Best Answer
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BWC Cybersecurity Overlord ✭✭✭
@FEDEL did you listed all (custom & default) rules for LAN to WAN and made sure that your deny rule is really where it meant to be?
Usually I disable all automatic rules in the zone configuration which means an implicit drop for not explicitely allowed traffic.
You also should check LAN to ANY, just in case.
—Michael@BWC
0
Answers
Thank you! There was in effect an "Lan to Any" permit rule with higher precedence than the "Lan to Wan" deny all, and removing that fixed the issue…. my bad i should have thought to this first…
Thank you again for your quick and precious support :)