ProxyJump does not accept IPv6 for the intermediate host?

[Adam Kalisz]

On Wed, 2024-03-13 at 11:41 +0000, Job Snijders wrote:
> On Wed, Mar 13, 2024 at 12:19:24PM +0100, Adam Kalisz wrote:
> > it seems I cannot use:
> > 
> > $ ssh -J root at 2a01:4f8:1c1e:528d::1 root at west-coast
> > Invalid -J argument
> 
> Try this:
> 
>     $ ssh -J root@[2a01:4f8:1c1e:528d::1] root at west-coast

Thank you all for helping with the syntax.

> Literal IPv6 addresses should be enclosed in square brackets, to
> avoid
> ambiguity between a colon-delimited port number and an IPv6 address.
> 
> Perhaps the -J documentation should point that out more explicitly?
> 
> Index: ssh.1
> ===================================================================
> RCS file: /cvs/src/usr.bin/ssh/ssh.1,v
> diff -u -p -r1.438 ssh.1
> --- ssh.1       11 Oct 2023 23:14:33 -0000      1.438
> +++ ssh.1       13 Mar 2024 11:37:57 -0000
> @@ -331,6 +331,7 @@ connection to the jump host described by
>  and then establishing a TCP forwarding to the ultimate destination
> from
>  there.
>  Multiple jump hops may be specified separated by comma characters.
> +IPv6 addresses can be specified by enclosing the address in square
> brackets.
>  This is a shortcut to specify a
>  .Cm ProxyJump
>  configuration directive.

This would be helpful! It should probably be noted that this syntax is
only valid in the -J/ ProxyJump context. Because:

$ ssh root@[2a01:4f8:1c1e:528d::1]
ssh: Could not resolve hostname [2a01:4ff:1f0:e68b::1]:: Name or service not known

does not work.

Thank you all for the prompt help!