[gentoo-user] Problem with Having two Network Cards in System ...

[gentoo-user] Problem with Having two Network Cards in System ...

[Christopher Koeber]

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Hello,

I have a system with two network cards. The cards are configured for DHCP
for two separate networks and they get their respective IP addresses from
the different DCHP servers.

The problem is that the network access on <I>either</I> network is sporatic
at best. The networks are as follows:

First, my network config file:

<B>/etc/conf.d/net</B>

-----------------------------
# This blank configuration will automatically use DHCP for any net.*
# scripts in /etc/init.d.  To create a more complete configuration,
# please review /etc/conf.d/net.example and save your configuration
# in /etc/conf.d/net (this file :]!).
config_eth0=( "dhcp" )
dhcpcd_eth0="-N"
config_eth1=( "dhcp" )
dhcpcd_eth1="-N"
-----------------------------


<B>ETH0:</B>
This is on a Gigabit network and I rarely, if ever, get access on this
network. This is an add-in card that I added after the initial installation.

Here is the ifconfig of eth0
-----------------------------
eth0      Link encap:Ethernet  HWaddr 00:26:f2:ac:c9:df
          inet addr:10.10.50.68  Bcast:10.10.50.255  Mask:255.255.255.0
          inet6 addr: fe80::226:f2ff:feac:c9df/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:69584 errors:0 dropped:492 overruns:0 frame:0
          TX packets:2291 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:5631144 (5.3 MiB)  TX bytes:237966 (232.3 KiB)
          Interrupt:23 Base address:0xc000
-----------------------------

<B>ETH1:</B>
This is on a 10/100 network and I get access sporatically on this network.
This card is a built-in card.

Here is the ifconfig of eth1
-----------------------------
eth1      Link encap:Ethernet  HWaddr 00:b0:d0:fc:51:c7
          inet addr:10.60.1.1  Bcast:10.60.255.255  Mask:255.255.0.0
          inet6 addr: fe80::2b0:d0ff:fefc:51c7/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:640794 errors:0 dropped:0 overruns:0 frame:0
          TX packets:57388 errors:2 dropped:0 overruns:0 carrier:2
          collisions:0 txqueuelen:1000
          RX bytes:63730861 (60.7 MiB)  TX bytes:17820579 (16.9 MiB)
-----------------------------

Now, both networks neet to be operational as I would like for the system
itself to be able to contact both networks and run services for each
network. However, the networks will NOT be bridged by the server in
question.

When i originally set up the system everything worked fine.

What do I need to do to make sure the system communicates to the networks in
question?

Thank you for your time.

Regards,
Christopher Koeber

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Re: [gentoo-user] Problem with Having two Network Cards in System ...

[Adam Carter]

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You need to break this down into the local (connected) networks, that is,
the subnet that the NIC are in and remote networks, that is, networks that
are reachable via ,say, the default gateway. My first guess is the the
default route is flipping back and forth as each NIC gets its address
renewal....

So when you next have connectivity problems, first check that you can ping
the IP address of another system on the same subnet as the NIC, and do this
for both NICs. I'm guess that will work. Then try pinging a remote system
and see how that correlates to where the default route is pointing, using
netstat -rn.

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Re: [gentoo-user] Problem with Having two Network Cards in System ...

[Bill Longman]

On 09/30/10 20:07, Christopher Koeber wrote:
> Hello,
> 
> I have a system with two network cards. The cards are configured for
> DHCP for two separate networks and they get their respective IP
> addresses from the different DCHP servers.
> 
> The problem is that the network access on <I>either</I> network is
> sporatic at best. The networks are as follows:
> 
> First, my network config file:
> 
> <B>/etc/conf.d/net</B>
> 
> -----------------------------
> # This blank configuration will automatically use DHCP for any net.*
> # scripts in /etc/init.d.  To create a more complete configuration,
> # please review /etc/conf.d/net.example and save your configuration
> # in /etc/conf.d/net (this file :]!).
> config_eth0=( "dhcp" )
> dhcpcd_eth0="-N"
> config_eth1=( "dhcp" )
> dhcpcd_eth1="-N"
> -----------------------------
> 
> 
> <B>ETH0:</B>
> This is on a Gigabit network and I rarely, if ever, get access on this
> network. This is an add-in card that I added after the initial installation.
> 
> Here is the ifconfig of eth0
> -----------------------------
> eth0      Link encap:Ethernet  HWaddr 00:26:f2:ac:c9:df 
>           inet addr:10.10.50.68  Bcast:10.10.50.255  Mask:255.255.255.0
>           inet6 addr: fe80::226:f2ff:feac:c9df/64 Scope:Link
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:69584 errors:0 dropped:492 overruns:0 frame:0
>           TX packets:2291 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 txqueuelen:1000
>           RX bytes:5631144 (5.3 MiB)  TX bytes:237966 (232.3 KiB)
>           Interrupt:23 Base address:0xc000
> -----------------------------
> 
> <B>ETH1:</B>
> This is on a 10/100 network and I get access sporatically on this
> network. This card is a built-in card.
> 
> Here is the ifconfig of eth1
> -----------------------------
> eth1      Link encap:Ethernet  HWaddr 00:b0:d0:fc:51:c7 
>           inet addr:10.60.1.1  Bcast:10.60.255.255  Mask:255.255.0.0
>           inet6 addr: fe80::2b0:d0ff:fefc:51c7/64 Scope:Link
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:640794 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:57388 errors:2 dropped:0 overruns:0 carrier:2
>           collisions:0 txqueuelen:1000
>           RX bytes:63730861 (60.7 MiB)  TX bytes:17820579 (16.9 MiB)
> -----------------------------
> 
> Now, both networks neet to be operational as I would like for the system
> itself to be able to contact both networks and run services for each
> network. However, the networks will NOT be bridged by the server in
> question.
> 
> When i originally set up the system everything worked fine.
> 
> What do I need to do to make sure the system communicates to the
> networks in question?
> 
> Thank you for your time.

Christopher, it would be helpful to see your network stack information.
What does "netstat -nr" tell you? Are you getting two default gateways?
That's a good way to get bad behaviour.