- General FAQ
- Q: Are you IPv6 Ready?
- A: We got several IPv6 Ready Logos. Please refer "IPv6 Ready?" on our web site for details.
- Q: Something is wrong on my USAGI !!
- A: Please report your problem with your situation including
the version of the USAGI kit (or patch),
series of your kernel (linux26, linux24 or linux22),
version of your glibc and
If you can attach kernel debug
messages, it is very helpful for us to solve the problem.
- Q: What license do USAGI products have ?
- A: There're two simple cases.
If you have licensing, and any other political issues, please contact
- You can use our original codes under
Please note that this is similar to the modified BSD License,
which is compatible with the GPL;
it does not include the advertising clause.
- Our codes based on GPL'ed softwares should be covered by the GPL;
you can use them under the GPL.
- Q: Does USAGI Project develop IPv6 stack separated from original Linux kernels ?
- A: We develop in separate cutting-edge repository based on the original Linux kernel.
We integrate our efforts to the mainline kernel if each of them becomes ready.
- Q: How often do you release snap and stable kit ?
- A: We release snapshot kit every two weeks and stable kit several times a year.
- Download FAQ
- Q: Which tarball should I download ?
- A: If you use linux-2.4.X kernel, you should download usagi-2003XXXX-linux24.tar.bz2.
If you use linux-2.6.X kernek, try usagi-2003XXXX-linux26.tar.bz2.
They're available at our ftp site.
- Q: I want only kernel patches and applications separately. Where can I get ?
- A: You can download snapshot kernel patches and applications from
the "split" directory.
- Q: I want the latest kernel patches.
- A: We provide daily kernel diffs
against linux-2.4.X and linux-2.6.X kernels.
- Q: Where can I get binary package ?
- A: We provide binary packages at each STABLE release for
Debian GNU/Linux, RedHat Linux and SuSE Linux.
You can get from
our ftp site.
- Q: How can I get the latest developing USAGI code ?
- A: You can use cvs pserver to get it. For details, please visit
- Kernel FAQ(General)
- Q: I have a problem to use any modules on linux-2.4.x kernel.
- A: Upgrade your modutils to 2.4.2 (or later).
- Q: I have a problem to use any modules on linux-2.6.x kernel.
- A: Install module-init-tools version 0.9.9 (or later).
- Q: Which kernel options should I enable in USAGI kernel ?
- A: Please see
INSTALL.USAGI file included in usagi kit.
The file explains how to make USAGI kernel and applications.
- Q: Where is IPsec for linux-2.4.x?
- A: We implemented IPsec for linux-2.4.x kernels.
It was, however, removed from our kit to concentrate developments for linux-2.6.x
Please remember that linux-2.6.x has IPsec.
If you really need IPsec for linux-2.4.x in any way, you may want to get
absolutely unsupported code from cvs branch tagged with bXFRM_[date].
- Q: Where is Mobile IPv6?
- A: (similar to "Where is IPsec for linux-2.4.x?")
We imported and improved Mobile IPv6 for linux-2.4.x kernels.
It was, however, removed from our kit to concentrate developments for linux-2.6.x.
Please note that USAGI Project and GO/Core Project
are corraborating for Mobile IPv6 development based on new implementation design.
- Q: Which algorithm for source address selection does USAGI IPv6 stack support ?
- A: We have supported RFC3484.
- Q: How to configure IPv6 with USAGI kernel ?
- A: Please read documents under doc directory in USAGI kit. Otherwise
is very useful.
- Q: Does USAGI IPv6 support multicast routing ?
- A: Currently no. But we have plan to implement multicast routing and routing daemons.
- Q: [obsolete] When I configure Linux box as an IPv6 router, it doesn't recognize IPv6 default route. Why ?
- A: It is a specification in original Linux kernel. However in USAGI kernel it has improved and
an IPv6 default route works as a default route. When you configure Linux as an IPv6 router,
we recommend to use USAGI kernel and enable CONFIG_IPV6_EN_DFLT option.
- Q: Are there any differences between compiling IPv6 as a module and build in ?
- A: No.
- Q: How can I configure IPv6 over IPv4 tunnel or 6to4 tunnel on Linux ?
- A: Please refer to Linux IPv6 HOWTO.
- Library FAQ
- Q: Why does USAGI project stop providing patches against glibc ?
- A: We make libinet6 library and our applications link it. It is built and
installed independent from glibc because it is very costly and dangerous to
- Q: Does USAGI IPv6 stack support RFC2292 or RFC3542 in usagi libinet6?
- A: Not yet completed. We are now working.
- Q: Why don't you support SO_REUSEPORT socket option ?
- A: If we introduce it, we have serious backward compatibility issues.
- Q: Does Linux support IPv6 transportations of DNS queries ?
- A: It is supported in glibc-2.2 or higher.
- Q: How can I get IPv6 addresses using SIOCGIFADDR ioctl ?
- A: You can't get IPv6 addresses by SIOCGIFADDR. Instead of SIOCGIFADDR ioctl, you can
get IPv6 address using getifaddrs(3) API in USAGI libinet6. The API is derived
- Q: I failed to configure libinet6; it complains that glibc version is unknown.
[from usagi-users 02057]
- A: You probably try to use codes which does not support the version of glibc of yours.
Stable 4 (or before) or, rather old snapshots does not
support glibc-2.3 series (including pre-2.3 series).
Please update your kit to latest.
- Application FAQ
- Q: Radvd doesn't work on USAGI kernel.
- A: Use the latest version of radvd, later than radvd-0.6.2.
- Q: Radvd doesn't work on linux-2.2.X USAGI kernel with message
"can't join ipv6-allrouters on eth0".
- A: Get latest USAGI patch for linux-2.2.X kernel.
- Q: I can't exec ping6 to link-local IPv6 with the message
"Invalid argument". Why ?
- A: You should specify a scope id with link-local address, for example
- Q: I can't exec ping6 to IPv4-mapped address. Why ?
- A: It is a specification. We don't allow bind IPv4 mapped address with raw IPv6 sockets.
- Q: Does USAGI Project have DHCPv6 implementations ?
- A: Currently no. The URL may help you, http://dhcpv6.sourceforge.net/.
$Id: faq.html,v 1.46 2005-06-09 12:37:58 kozakai Exp $
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