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Subject: Re: Incorrect route interface
To: freebsd-net@freebsd.org
References: <9dd657bc-ad58-f5cb-327a-572a561f1d6b@gjunka.com>
 <5AA45F89.7090800@grosbein.net>
From: Grzegorz Junka <list1@gjunka.com>
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Date: Sun, 11 Mar 2018 00:01:59 +0000
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On 10/03/2018 22:43, Eugene Grosbein wrote:
> 11.03.2018 5:01, Grzegorz Junka wrote:
>
>> In rc.conf I have:
>>
>> hostname="some.server.com"
>> ifconfig_em0="inet 10.20.2.14 netmask 255.255.0.0"
>> ifconfig_em1="inet 10.20.2.15 netmask 255.255.0.0"
>> ifconfig_igb0="inet 10.20.2.16 netmask 255.255.0.0"
> Just do not assign addresses from same network 10.20.0.0/16 to different network interfaces
> and you will be fine. Assign them all to right interface:
>
> ifconfig_em0="inet 10.20.2.14 netmask 255.255.0.0"
> ifconfig_em0_alias0="inet 10.20.2.15/32"
> ifconfig_igb0_alias0="inet 10.20.2.16/32"
>
> Do not try to use several physical network cards to connect hosts using just one IP network
> as generally each card/interface needs distinct IP network to work flawlessly.
>

Did you mean:

ifconfig_em1_alias0="inet 10.20.2.15/32"

I don't quite understand how you can assign an alias to an interface 
(igb0 in this case) without configuring it with an IP first? According 
to the documentation an alias is an additional network address, not the 
only one?