The max UDP message size is currently hardcoded to 9012. We would like to increase it, since our max workload message size is greater. Quick fix: export CHISEL_UDP_MAX_SIZE=12000 share\tunnel\tunnel_out_ssh_udp.go:80 share\tunnel\tunnel_in_proxy_udp.go:83 const maxMTU = settings.EnvInt("UDP_MAX_SIZE", 9012) or command line param e.g. --udp-max-size 12000