two ethernet cards

[maddaemon at gmail.com]

On Sat, Jan 3, 2009 at 3:24 PM, Derek Ragona
<derek at computinginnovations.com> wrote:
> At 06:21 PM 1/2/2009, Stefan Miklosovic wrote:
>>
>> hi
>>
>> i have two ethernet cards on my box
>>
>> uname -a
>> FreeBSD dexter 7.0-RELEASE Freebsd 7.0-RELEASE #5: Fri Jan   2 21:25:21
>> CET
>> 2009  root at dexter:/usr/obj/usr/src/sys/DEXTER   i386
>>
>> ifconfig
>> rl0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
>>    options=8<VLAN_MTU>
>>    ether XX:XX:XX:XX:XX:XX
>>    inet 192.168.0.177 netmask 0xffffff00 broadcast 192.168.0.255
>>    media: Ethernet 100baseTX
>>    status: active
>> sk0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
>>    options=b<RXCSUM,TXCSUM,VLAN_MTU>
>>    ether XX:XX:XX:XX:XX:XX
>>    inet 192.168.0.176 netmask 0xffffff00 broadcast 192.168.0.255
>>    media: Ethernet 100baseTX (100baseTX <full-duplex>)
>>    status: active
>> lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
>>    inet6 fe80::1%lo0 prefixlen 64 scopeid 0x3
>>    inet6 ::1 prefixlen 128
>>    inet 127.0.0.1 netmask 0xff000000
>>
>> when I want to ping sk0 from eth0 on linux box, ping is ok, but this
>> message
>> appears to me in freebsd console
>>
>> Jan 3 01:07:39 dexter kernel: arp: 192.168.0.2 is on rl0 but got reply
>> from
>> XX:XX:XX:XX:XX:XX on sk0
>>
>> linux command
>> ping -I eth0 192.168.0.176
>>
>> linux ifconfig
>>
>> eth0      Link encap:Ethernet  HWaddr XX:XX:XX:XX:XX
>>          inet addr:192.168.0.2  Bcast:192.168.0.255  Mask:255.255.255.0
>>          inet6 addr: fe80::20a:e4ff:fef3:abb6/64 Scope:Link
>>          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>>          RX packets:3 errors:0 dropped:0 overruns:0 frame:0
>>          TX packets:88 errors:0 dropped:0 overruns:0 carrier:0
>>          collisions:0 txqueuelen:1000
>>          RX bytes:180 (180.0 B)  TX bytes:11542 (11.2 KB)
>>          Interrupt:22 Base address:0x3000
>>
>> lo        Link encap:Local Loopback
>>          inet addr:127.0.0.1  Mask:255.0.0.0
>>          inet6 addr: ::1/128 Scope:Host
>>          UP LOOPBACK RUNNING  MTU:16436  Metric:1
>>          RX packets:416 errors:0 dropped:0 overruns:0 frame:0
>>          TX packets:416 errors:0 dropped:0 overruns:0 carrier:0
>>          collisions:0 txqueuelen:0
>>          RX bytes:25130 (24.5 KB)  TX bytes:25130 (24.5 KB)
>>
>> wlan0     Link encap:Ethernet  HWaddr XX:XX:XX:XX:XX:XX
>>          inet addr:192.168.0.173  Bcast:192.168.0.255  Mask:255.255.255.0
>>          inet6 addr: fe80::214:a4ff:fe79:3cbc/64 Scope:Link
>>          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>>          RX packets:30030 errors:0 dropped:0 overruns:0 frame:0
>>          TX packets:25399 errors:0 dropped:0 overruns:0 carrier:0
>>          collisions:0 txqueuelen:1000
>>          RX bytes:32882410 (31.3 MB)  TX bytes:3522346 (3.3 MB)
>>
>> mac adres from eth0 on linux machine is same as from the error output on
>> bsd
>>
>>
>>
>> thank you a lot
>>
>> stewe
>
> With two NIC's in the same system they need to be on separate and discrete
> subnets.  If these are put into a dumb switch, you will still get arp
> errors.  You need to connect each NIC to a separate network or VLAN.
>
>        -Derek

I disagree.  I have numerous boxen with dual NICs that are on the same
subnet/VLAN.

OOC, why do you state they "need" to be on different subnets?