OPNsense Forum

Archive => 20.7 Legacy Series => Topic started by: seed on August 27, 2020, 07:45:37 pm

Title: [SOLVED] Weird UDP Problems
Post by: seed on August 27, 2020, 07:45:37 pm
I have noticed an weird UDP issue.

My Setup:

The OPnsense is running on hardware and connected by PPPoe.

Windows Clients are not able to connect to external NTP Servers (outside of my Network), IPsec Clients in my network cant connect to their servers (outside of my Network)

When i tcpdump on the (internal) vlan interface i cannot see any udp packages being captured. The snat rules are set to default. asking the ntp server with linux: ntpdate -q $Server works fine (ipv4 + IPv6)

I have set rules that allow outgoing UDP + TCP + ICMP + ANY but outgoing IPSec, or Windows NTP does not work.

My Firewall Rules are mostly set to sloppy. What is happening? Even after a fresh install the issue persists.
Is the Interface "throuing out" these packages so that i cant see them in tcpdump? is this related to netmap? i dont have suricata running.

When these clients connect to our "Freifunk" their applications work fine and they are able to connect to the ntp servers or the IPSec Servers.
Title: Re: Weird UDP Problems
Post by: seed on September 04, 2020, 01:49:42 pm
Solved.

a faulty switch caused the weird problems. Its ddos protection dropped the frames without logging thase incidents.