Networking from vm to nested vm problems


New Member
Nov 24, 2021

I think I have a simliar problem to the one discussed in this thread:

Basically I can't access an "L2" vm from a different "L1" VM, however from an external laptop everything is working well.

As an additional oddity, ping from the L1 to L2 seems to work and it seem to be TCP traffic that's affected?

On the L2, tcpdump does capture the icmp ping traffic, and it shows that every tcp packet has a checksum error.

Specifically I have a Windows 11 Eval VM and a GNS3VM, and inside the GNS3VM I'm running a Palo Alto firewall with the Management NIC mapped to the gns3 eth0. The Win11 VM can't connect to the PA's management console but it works from a laptop outside of ProxMox.


Attached a packet capture from the PA with
tcpdump filter "host and not port 22"

where .151 is the other proxmox vm. Ping is successful, attempt to open a port to 443 fails, Trying a browser to 443 fails, again try telnet 443 and finally a successful ping again.


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Last edited:
Just to change things up I changed the management IP to and added as a second IP to the windows client and made two more captures. Ping still works but tcp to port 443 does not.


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Having the exact same issue, I know its been almost a year but did you find a solution?


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