topic Re: Packets retransmission captured in packet capture on firewall but still seems dropping in Next-Generation Firewall Discussions

Packets retransmission captured in packet capture on firewall but still seems dropping

mhannan313 — Mon, 01 Jan 2024 12:06:48 GMT

Recently trying to debug a possible packet dropping issue at firewall (screenshot attached for reference). The issue is appearing when I try to make request to my server from my iOS device, some API calls works Ok but often few of those fails with 503 error code and this happens randomly against different APIs.

When I looked at the firewall the failed request packets appear in the packet capture but doesn't appear in the firewall traffic logs. I tried to filter the denied traffic but nothing appeared there.

The question is when packets are coming then how come those are not being served and transferred to the target server?

Can anyone share some more details to look into or any possible problem that is hampering the traffic? I see the retransmission packets for the failed request (see attachment).

Re: Packets retransmission captured in packet capture on firewall but still seems dropping

OtakarKlier — Tue, 02 Jan 2024 19:31:49 GMT

Hello,

Make sure you have logging enabled on all policies and check the unified logs on the Palo Alto.

Regards,

Re: Packets retransmission captured in packet capture on firewall but still seems dropping

reaper — Wed, 03 Jan 2024 00:07:01 GMT

it's possible somehow your dropped packet is hitting the default rule which doesn't have logging by default

If you set up packet captures i'd recommend running 'show counter global filter delta yes packet-filter yes' in tandem with your tests to see if any weird global counters pop up matching your packet capture filters that can explain why the packet is discarded