FreeBSD 5.0 dual-stack server

Hajimu UMEMOTO ume at
Sun Mar 30 11:01:04 PST 2003


>>>>> On Thu, 27 Mar 2003 16:21:40 -0700
>>>>> "Jeff W. Boote" <boote at> said:

boote> In any case - my server code works fine on 4.6 and 4.7 binding to both
boote> address families. However, I have just received a report of it only
boote> binding the v6 address on a FreeBSD 5.0 system. (As reported from
boote> "netstat -a -p tcp" - and by the fact that clients that try and use the
boote> v4 address are unable to get a connection.)

boote> It is behaving as if the IPV6_BINDV6ONLY sockopt is set... Has the
boote> "default" value for this changed?

BTW, IPV6_BINDV6ONLY has been superseded by IPV6_V6ONLY.

boote> Is it recommended that any server that wants to bind to the dual-stack
boote> needs to make sure this sockopt is unset? I am not doing that...

Yup, where you can do it, you should do so.
However, I suggest opening two sockets, one is for IPv6 and the other
is for IPv4, instead of using IPv4-mapped IPv6 address.

boote> I just found the net.inet6.ip6.bindv6only sysctl variable doing a web
boote> search... What is the default value for this sysctl on 5.0?

net.inet6.ip6.bindv6only=1 by default on 5-CURRENT.

boote> (I guess I may need to install 5.0 on a box, and stop bothering
boote> others...)

You don't need to install 5.0.  You can simply get same effect by
setting net.inet6.ip6.bindv6only=1.


Hajimu UMEMOTO @ Internet Mutual Aid Society Yokohama, Japan
ume at  ume at  ume@{,jp.}

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