c : fatal: server died with error code 255

Hi,

I want to use sshuttle inside my servers! but it get my own ssh connection disconnect!

I have two ubuntu servers, and i want to use sshttle between those but as i connect via ssh to one of them and then i want to run sshuttle, So my own ssh connection to one of them get dissconected and thus the whole sshuttle get an error ( while i use tmux).

here is the error:

sshuttle --dns -r ubuntu@10.10.10.56 0/0 --ssh-cmd 'ssh -i Aha.pem' -vvv
Starting sshuttle proxy.
firewall manager: Starting firewall with Python version 3.8.10
firewall manager: ready method name nat.
IPv6 enabled: False
UDP enabled: False
DNS enabled: True
User enabled: False
Binding redirector: 12300
TCP redirector listening on ('127.0.0.1', 12300).
TCP redirector listening with <socket.socket fd=5, family=AddressFamily.AF_INET, type=SocketKind.SOCK_STREAM, proto=0, laddr=('127.0.0.1', 12300)>.
Binding DNS: 12300 12299
DNS listening on ('127.0.0.1', 12299).
DNS listening with <socket.socket fd=7, family=AddressFamily.AF_INET, type=SocketKind.SOCK_DGRAM, proto=0, laddr=('127.0.0.1', 12299)>.
Starting client with Python version 3.8.10
c : connecting to server...
c : executing: ['ssh', '-i', 'Aha.pem', 'ubuntu@10.10.10.56', '--', 'exec /bin/sh -c \'P=python3; $P -V 2>/dev/null || P=python; exec "$P" -c \'"\'"\'import sys, os; verbosity=3; sys.stdin = os.fdopen(0, "rb"); exec(compile(sys.stdin.read(1317), "assembler.py", "exec"))\'"\'"\'\'']
c :  > channel=0 cmd=PING len=7 (fullness=0)
c : Connected.
c : Waiting: 3 r=[5, 7, 9] w=[9] x=[] (fullness=7/0)
assembler.py:3: DeprecationWarning: the imp module is deprecated in favour of importlib; see the module's documentation for alternative uses
server: assembling 'sshuttle' (7 bytes)
server: assembling 'sshuttle.cmdline_options' (66 bytes)
server: assembling 'sshuttle.helpers' (944 bytes)
server: assembling 'sshuttle.ssnet' (5776 bytes)
server: assembling 'sshuttle.hostwatch' (2388 bytes)
server: assembling 'sshuttle.server' (3787 bytes)
Starting server with Python version 3.8.10
 s: latency control setting = True
 s:  > channel=0 cmd=PING len=7 (fullness=0)
 s: auto-nets:False
 s:  > channel=0 cmd=ROUTES len=0 (fullness=7)
 s: Waiting: 1 r=[0] w=[1] x=[] (fullness=7/0)
 s:   Ready: 1 r=[] w=[1] x=[]
 s: mux wrote: 15/15
 s: Waiting: 1 r=[0] w=[1] x=[] (fullness=7/0)
 s:   Ready: 1 r=[] w=[1] x=[]
 s: mux wrote: 8/8
 s: Waiting: 1 r=[0] w=[] x=[] (fullness=7/0)
c :   Ready: 3 r=[9] w=[9] x=[]
c : <  channel=0 cmd=PING len=7
c :  > channel=0 cmd=PONG len=7 (fullness=7)
c : <  channel=0 cmd=ROUTES len=0
firewall manager: Got subnets: [(2, 0, False, '0.0.0.0', 0, 0), (2, 32, True, '127.0.0.1', 0, 0)]
firewall manager: Got partial nslist: [(2, '127.0.0.53')]
firewall manager: Got nslist: [(2, '127.0.0.53')]
firewall manager: Got ports: 0,12300,0,12299
firewall manager: Got udp: False, user: None
firewall manager: setting up.
firewall manager: setting up IPv4.
>> iptables -t nat -N sshuttle-12300
>> iptables -t nat -F sshuttle-12300
>> iptables -t nat -I OUTPUT 1 -j sshuttle-12300
>> iptables -t nat -I PREROUTING 1 -j sshuttle-12300
>> iptables -t nat -A sshuttle-12300 -j RETURN --dest 127.0.0.1/32 -p tcp
>> iptables -t nat -A sshuttle-12300 -j REDIRECT --dest 0.0.0.0/0 -p tcp --to-ports 12300 -m ttl ! --ttl 42
>> iptables -t nat -A sshuttle-12300 -j REDIRECT --dest 127.0.0.53/32 -p udp --dport 53 --to-ports 12299 -m ttl ! --ttl 42
c : mux wrote: 15/15
c : mux wrote: 15/15
c : Waiting: 3 r=[5, 7, 9] w=[] x=[] (fullness=14/0)
client_loop: send disconnect: Broken pipe
c :   Ready: 3 r=[9] w=[] x=[]
firewall manager: undoing changes.
firewall manager: undoing IPv4 changes.
>> iptables -t nat -D OUTPUT -j sshuttle-12300
>> iptables -t nat -D PREROUTING -j sshuttle-12300
>> iptables -t nat -F sshuttle-12300
>> iptables -t nat -X sshuttle-12300
firewall manager: undoing /etc/hosts changes.
c : fatal: server died with error code 255

Start by reproducing the reported sshuttle --dns command between the two Ubuntu servers and review the verbose output around iptables setup and the SSH broken-pipe disconnect. The issue names no repository file or test, so first determine whether the failure is reproducible and identify the component responsible; done means establishing a clear fix or confirmed external cause.