Thanks, I found the problem by inspection of src/lib9/_p9dialparse.c.
IPv6 is indeed the default when using an address of tcp!*!17034
 /* translate host */
if(strcmp(host, "*") == 0){
ss->ss_family = AF_INET6;
((struct sockaddr_in6*)ss)->sin6_addr = in6addr_any;
}else if((he = gethostbyname(host)) != nil && he->h_addr_list[0] != nil){

So, setting the address string to tcp!dell-openbsd!17034 fixed the problem.
My Linux machines actually have an IPv6 address, the OpenBSD box does not,
so that explains the difference.

Ole-Hj.

On Mon, May 4, 2020 at 10:09 PM <ori@eigenstate.org> wrote:

> > I can connect to the venti from localhost, but not from any other
> machine.
> > However, if I run nc -l on ports 17034 and 80, I can connect from any
> > machine. It is definitely not the packet filter, since the problem
> persists
> > even if I disable the packet filter. Any suggestions about what might be
> > blocking the connection?
>
> My first guess is that it's listening on the wrong interface.
> Run it under 'ktrace', then run 'kdump' and look for the bind()
> calls and friends.
>
>