Re: Request for Support: QEMU IPv6 Port Forwarding Issue

[Thomas Huth <thuth@redhat.com>]

On 19/03/2024 06.53, Srinivasu Kandukuri (MS/ECP2-ETAS-VOS) wrote:
> Dear QEMU Support Team,
> 
> We are currently encountering difficulties in utilizing QEMU for starting a 
> virtual machine image on Windows with IPv6 networking, specifically related 
> to port forwarding. We are using QEMU emulator version 7.1.93 
> (v7.2.0-rc3-11946-gb68e69cdcc-dirty).
> 
> Our objective is to establish IPv6 network connectivity within the virtual 
> machine and forward ports to allow external access. However, we are 
> encountering errors when attempting to configure the port forwarding mechanism.
> 
> Here is the command we are using:
> 
> *qemu-system-x86_64: -netdev 
> user,id=net1,ipv6=on,ipv6-net=fe80::5054:ff:fecd:585a/64,hostfwd=tcp::2210-[fe80::5054:ff:fecd:585a]:22*
> 
> However, upon executing this command, we encounter the following error:
> 
> *Invalid host forwarding rule 'tcp::2210-[fe80::5054:ff:fecd:585a]:22' (Bad 
> guest address)*
> 
> We understand that the format for specifying host forwarding rules follows 
> the pattern:
> 
> *protocol:[listen_address]:listen_port-[dest_address]:dest_port*
> 
> We believe that we are following this pattern correctly, but still, we are 
> encountering errors.

  Hi!

Looking at the code:

  https://gitlab.com/qemu-project/qemu/-/blob/v8.2.0/net/slirp.c#L824

it seems like QEMU is only using inet_aton() here, which means IPv4 only, 
sorry, but this likely needs some additional changes first to support IPv6 
addresses here.

  Thomas


> Our primary concern is whether QEMU supports port forwarding for IPv6 
> networking. If it does, we kindly request your assistance in resolving this 
> issue and providing guidance on the correct configuration for achieving our 
> objective.
> 
> Could you please advise us on the proper usage of port forwarding with IPv6 
> networking in QEMU? Any insights, suggestions, or instructions you can 
> provide would be greatly appreciated.
> 
> Thank you very much for your attention to this matter. We look forward to 
> your prompt response and assistance.
> 
> Mit freundlichen Grüßen / Best regards
> 
> *Kandukuri Srinivasu*
> 
> (MS/ECP2-ETAS-VOS)
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