Re: Does FreeBSD stack support multiple IP addresses?

[Grant Edwards <grant dot b dot edwards at gmail dot com>]

On 2016-02-22, Lambrecht JÃrgen <J.Lambrecht@TELEVIC.com> wrote:
> On 02/19/2016 07:11 PM, Grant Edwards wrote:
>> On 2016-02-19, Grant Edwards <grant.b.edwards@gmail.com> wrote:
>>
>>> Can one assign multiple IP addresses (on different subnets) to a
>>> single interface when using the eCos FreeBSD network stack?
[...]
>> You use SIOCAIFADDR(_IN6) instead of SIOCASIFADDR and its brethren.
>
> I had 2 problems to assign 2 IP addresses with different netmasks:
>
> - To assign an IP address an set a netmask are 2 different ioctl
>   calls.  To set the netmask, you cannot specify for which IP
>   address you set it.  The code (current/src/sys/netinet/in.c) is
>   written in such a way that the netmask is set on the last IP
>   address you added on that interface.  So that should be OK if you
>   keep the correct order.

When I tried it, the SIOCAIFADDR ioctl() let me set both address and
netmask in a single call.  The "case SIOCAIFADDR" code falls through
into SIOCSIFNETMASK code.  That didn't work for you?

> - It is only possible to assign a class A/B/C netmask. CIDR netmasks are 
>   not possible.

I think that's always been the case for this version of the stack,
hasn't it?

>   I fixed current/src/sys/netinet/in.c for it, but I also 
>   adapted the ioctl to combine setting IP address and netmask in 1 call 
>   (so I cannot commit it back). Let me know if you want my fix.

I'm confused: based on my experiments and examination of the source
code, it already works that way.

-- 
Grant Edwards               grant.b.edwards        Yow! Psychoanalysis??
                                  at               I thought this was a nude
                              gmail.com            rap session!!!


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