Comunication on VLAN blocked - tcpdump unblocks it?

[Tron2001]

Hello Everybody,

since the last update (17.1.10 - may be I missed some) I have a wired problem on a VLAN tagged interface, which is the guest network.
Any communcation is blocked on that interface until I start tcpdump on that interface.
I am not a network expert, so I don't know what tcpdump eventually triggers.

Since in the guest network there is only a linux based wifi gateway, I can see there which pakets are send to the VLAN.
And I does not see any responses. So I wanted to see what happens at the corresponding interface of my opnsense machine.

In the moment I started there the tcpdump the replys where send.

I checked the firewall rules, if anything may be wrong, but I could not find such kind of a blocking rule.

Can anybody give me a hint? May it is a bug?
What information you will need?

Danke und Viele Grüße
Thomas

[Tron2001]

A word to the firewall: their deactivation did not change the blocking of packets.

Gruß
Thomas

[franco]

Hi Thomas,

It sounds like a connectivity / switching issue with the VLAN. tcpdump can fiddle with the interface mode, maybe set promiscuous mode so packets start flowing, ARP tables fill up which previously didn't happen. How is the VLAN connected? What hardware is behind it?


Cheers,
Franco

[Tron2001]

Hi Franco,

thanks for this hint.
OpnSense runs in a virtual maschine powered by VirtualBox.

The adapter is paravirtualized. Phisically it is a Intel 82579L with an e1000e Host Kernel module.

Ups. Didn't I read about a problem with the e1000 device in the anouncements.

I will review it.

Viele Grüße
Thomas

[Tron2001]

Just to update the status - for me it works now again.

I did change the configuration of the virtual machine to Intel Server network card.
Created the vlan interface on the host server without IP configuration  and passed this to the virtualized opnsense.

Changing the network card caused a lot of reconfiguration work, but now I am a bit more experienced with the basic configuration stuff  ;-)

Viele Grüße
Thomas