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IPS Service - with no FW rules - Prevents Certain Sites from Loading

I'm running V19 in bridge mode. Very basic setup, haven't really gotten far with it yet.

I've noticed that even though I have no firewall rules with IPS enabled, certain sites - like this one(!) time out unless I stop the IPS system service under "system services -> services" - And I'm not seeing any errors in /log/ips.log. When I disable that system service, the problem stops.

Here are my firewall rules:

(Note I disabled the default NAT rule because this is an internal bridged setup, no NAT needed).

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0 mark57165 over 1 year ago

I'm still trying to figure this one out. I can't find anything wrong with my configuration that would cause this. Is it possible this is a bug that's occurring with bridged mode?
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0 mark57165 over 1 year ago

The affected sites seem to be internal to my network - I have multiple subnets. It seems to happen when the connection is TLS-encrypted - whether it's websites or other TLS-encrypted connections - but this happens without the proxy or decryption.

What's interesting is that I can *open a connection* to the affected resources, e.g. using telnet.
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0 Wayne Folta over 1 year ago in reply to mark57165

Are you sure there's no decryption happening? (For example, monitor the TLS log in Log Viewer to see.) TLS decryption can be tricky in that you might think you set it in a Firewall rule, but the checkbox is not setting decryption, it's setting HTTP inspection (and HTTPS if you happen to have decryption happening due to TLS rules).
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0 mark57165 over 1 year ago in reply to Wayne Folta

I'll double-check that. One thing I did just notice a few minutes ago is that if I turn off the SSL/TLS Engine in Rules and Policies > SSL/TLS Inspection Rules > SSL/TLS Inspection Settings > Advanced, everything begins to work again.

I'll review the TLS log.
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0 mark57165 over 1 year ago in reply to Wayne Folta

When I do a policy test, I get:

Which appears correct, it's not trying to decrypt it...
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0 mark57165 over 1 year ago in reply to Wayne Folta

Reviewing the ips.log, I am seeing this occur:

ips.log:2022-05-31T05:44:14.086148Z [17341/0x0] [nsg_nse_policy.c:1572:__nsg_error] 10.1.1.20:52028 to 10.1.0.10:8006: Error from nse: NSE:Internal [0xb0000586;code:134;sub:5] Flow timeout
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