TCP Previous segment not captured

[JCzz]

ENV

multipass version
multipass   1.10.1+mac
multipassd  1.10.1+mac

Mac Apple M1
MacOS 12.5.1

I am using two Mac computers, both MacOS M1 client and server.

curl hangs half way through a large file(small file no problem) , if the server is running in multipass on different vlan/network(See step 7. )

curl <--> network <--> host computer <--> multipass vm

Steps

You need to install go on the computer on the different vlan/network and do the following:

1. Create multipass vm and mount from the same folder:

multipass launch --name myvm --network=en0
multipass mount . myvm:~/speed

2. Install go

multipass shell myvm
cd speed
sudo snap install go --classic

3. Generate a large file:

base64 /dev/urandom | head -c 100000 > file.txt
echo "\The end" >> file.txt

Note: Using one zero less base64 /dev/urandom | head -c 10000 > file.txt then there is no problem.

4. Create the following go file main.go in the same folder(you could also just do "python3 -m http.server"):

package main

import (
	"github.com/gorilla/mux"
	"log"
	"net/http"
)

func main() {
	handler := mux.NewRouter()
	handler.PathPrefix("/").Handler(http.StripPrefix("/", http.FileServer(http.Dir("."))))
	log.Fatal(http.ListenAndServe(":80", handler))
}

5. Run go on multipass myvm on different vlan/network

go mod init test
go get
sudo go run main.go

From client machine on another vlan/network

6. Curl to multipass mvm, IMPORTANT to multipass ip address, on the network(--network=en0), from "another" machine:

curl <ip>/file.txt
In my case: `curl 192.170.1.231/file`
7AVzmECVWNbcShP+TE+/6AM/KZWc12AzLKvtctv0pqeSW0SNDW3OSM82SkzF+/UExUUBH4dxlIcM
dObLOlLgz9WfoiEtvZ4Hbx/yq85C+WwnFr2Trhu75qmFrg8Ht8t/x+MyDfI0MyuGw91tKqFgHL4F

Now it hangs, what to do?

If you run this on the multipass host computer(same ip address) it works, just not from multipass vm - again between networks.

Note: multipass list:

Name                    State             IPv4             Image
mvm                     Running           192.168.64.132   Ubuntu 20.04 LTS
                                          192.170.1.231

If I use Wireshark I can see something standing out right about where it hangs:

10287	0.000580	0.000580	64	192.168.1.22	192.170.1.231	TCP	54	53941 → 80 [RST] Seq=1 Win=0 Len=0

4818	0.004338	0.004338	62	192.170.1.231	192.168.1.22	TCP	1514	[TCP Previous segment not captured] 80 → 50623 [ACK] Seq=84853 Ack=86 Win=65152 Len=1448 TSval=1019606200 TSecr=2732723127 [TCP segment of a reassembled PDU]

4820	0.000249	0.000249	64	192.168.1.22	192.170.1.231	TCP	78	[TCP Dup ACK 4817#1] 50623 → 80 [ACK] Seq=86 Ack=67477 Win=131072 Len=0 TSval=2732723132 TSecr=1019605978 SLE=84853 SRE=86301

4821	0.000057	0.000057	64	192.168.1.22	192.170.1.231	TCP	78	[TCP Dup ACK 4817#2] 50623 → 80 [ACK] Seq=86 Ack=67477 Win=131072 Len=0 TSval=2732723132 TSecr=1019605978 SLE=84853 SRE=87749

4822	0.002414	0.002414	62	192.170.1.231	192.168.1.22	TCP	1514	[TCP Fast Retransmission] 80 → 50623 [ACK] Seq=67477 Ack=86 Win=65152 Len=1448 TSval=1019606202 TSecr=2732723132 [TCP segment of a reassembled PDU]

4823	0.000001	0.000001	62	192.170.1.231	192.168.1.22	TCP	1514	[TCP Out-Of-Order] 80 → 50623 [ACK] Seq=68925 Ack=86 Win=65152 Len=1448 TSval=1019606203 TSecr=2732723132 [TCP segment of a reassembled PDU]

4827	0.002141	0.002141	62	192.170.1.231	192.168.1.22	TCP	1514	[TCP Out-Of-Order] 80 → 50623 [ACK] Seq=70373 Ack=86 Win=65152 Len=1448 TSval=1019606205 TSecr=2732723135 [TCP segment of a reassembled PDU]

4829	0.000165	0.000165	62	192.170.1.231	192.168.1.22	TCP	1514	[TCP Retransmission] 80 → 50623 [PSH, ACK] Seq=71821 Ack=86 Win=65152 Len=1448 TSval=1019606205 TSecr=2732723135

4830	0.000002	0.000002	62	192.170.1.231	192.168.1.22	TCP	1514	[TCP Retransmission] 80 → 50623 [ACK] Seq=73269 Ack=86 Win=65152 Len=1448 TSval=1019606205 TSecr=2732723135

4831	0.000000	0.000000	62	192.170.1.231	192.168.1.22	TCP	1514	[TCP Retransmission] 80 → 50623 [ACK] Seq=74717 Ack=86 Win=65152 Len=1448 TSval=1019606205 TSecr=2732723135

I have added this issue to:
Hyperkit: moby/hyperkit#338
Qemu: https://gitlab.com/qemu-project/qemu/-/issues/1584
stackoverflow.com: https://stackoverflow.com/questions/73753103/multipass-tcp-previous-segment-not-captured

Thanks

[JCzz]

Is this really not an issue, and/or am I the only one with this issue?

[JCzz]

Created a simplified issue: #3038