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Multipass bridged network not accepting connections from internet

cn flag
Justin Oroz

I have a Ubuntu 20.04.3 LTS VM in Multipass running which I want to expose to the internet via router port forwarding. The VM is using bridged network mode. If I run nc -l -p 8080 in the VM and listen to the port I can see connections initiated from within the bridged network. However requests which are forwarded from my router are not arriving.

ubuntu@microk8s-vm:~$ ip a
3: enp0s8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc fq_codel state UP group default qlen 1000
    link/ether 55:54:00:ad:68:aa brd ff:ff:ff:ff:ff:ff
    inet 192.168.86.123/24 brd 192.168.86.255 scope global dynamic enp0s8
       valid_lft 81708sec preferred_lft 81708sec
    inet6 fd46:2d25:460a:436e:5054:ff:fead:68cb/64 scope global dynamic mngtmpaddr noprefixroute 
       valid_lft 1786sec preferred_lft 1786sec
    inet6 fe80::5054:ff:fead:68cb/64 scope link 
       valid_lft forever preferred_lft forever

I've tested the port-forwarding by hosting a web server on the host machine and forwarding to its address with success.

How can allow external connections through to the VM?

Edit:

Potentially relevant line from tcpdump on the host machine when making a request from YouGetSignal Port Forwarding Tester

15:56:36.643672 IP 198.199.98.246.50138 > microk8s-vm.lan.http: Flags [S], seq 304495333, win 14600, options [mss 1460,sackOK,TS val 979766022 ecr 0,nop,wscale 8], length 0
15:56:36.643680 IP 198.199.98.246.50145 > microk8s-vm.lan.http: Flags [S], seq 2904338462, win 14600, options [mss 1460,sackOK,TS val 979766022 ecr 0,nop,wscale 8], length 0
15:56:37.644183 IP 198.199.98.246.50145 > microk8s-vm.lan.http: Flags [S], seq 2904338462, win 14600, options [mss 1460,sackOK,TS val 979766272 ecr 0,nop,wscale 8], length 0
15:56:37.649490 IP 198.199.98.246.50150 > microk8s-vm.lan.http: Flags [S], seq 3462120669, win 14600, options [mss 1460,sackOK,TS val 979766272 ecr 0,nop,wscale 8], length 0
15:56:38.643138 IP 198.199.98.246.50150 > microk8s-vm.lan.http: Flags [S], seq 3462120669, win 14600, options [mss 1460,sackOK,TS val 979766522 ecr 0,nop,wscale 8], length 0
15:56:40.652553 ARP, Request who-has microk8s-vm.lan tell 192.168.86.1, length 46
15:56:40.652670 ARP, Reply microk8s-vm.lan is-at xx:xx:xx:xx:xx:xx (oui Unknown), length 28
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cn flag
Justin Oroz
The VM driver is Virtual Box using bridged network mode.
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David avatar
cn flag
David
If this comment is more info for the question please edit the question and put the info there not as a comment.
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Saviq avatar
de flag
Saviq
Hi Justin, what's your host? It would be interesting to know if the external packets arrive at your host at all. `tcpdump` would be a good choice on macOS, there's likely a similar tool for Windows.
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cn flag
Justin Oroz
The host machine is macOS. I'm not familiar with `tcpdump` so I'm not sure what I'm looking for. greping for my VM and an in network machine I can see activity when requesting from in the network. There is so much activity from the VM it is hard to determine what is happening when attempting to look for external connections.
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cn flag
Justin Oroz
I've edited the question to add some potentially relevant lines
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