problems with gigabit speeds on dual network card
Gilboa Davara
gilboad at gmail.com
Sun Sep 19 05:18:04 UTC 2010
On Sat, 2010-09-18 at 21:08 -0400, Genes MailLists wrote:
>
> Anyone got any suggestions for this.
>
> I have a linksys sr2024 Gb switch
>
> Several things are plugged into this - all using cat 5e or cat 6 cables.
>
>
> Some things are connecting with full Gb speed but the main firewall wont.
>
> The machine has 3 intel nic's -
>
> lspci | egrep -i ethernet
> 04:00.0 Ethernet controller: Intel Corporation 82573L Gigabit Ethernet
> Controller (rev 01)
> 05:04.0 Ethernet controller: Intel Corporation 82541PI Gigabit Ethernet
> Controller (rev 05)
> 05:05.0 Ethernet controller: Intel Corporation 82541PI Gigabit Ethernet
> Controller (rev 05)
>
> The 82573 is on board and not used - the other 2 nic's are used - one
> for internal subnet and one for external.
>
> The internet side is connected to a cisco 800 router (which I believe
> is 10/100 only .. tho I cudnt swear for sure)
>
> The inside is connected to the SR2024 Gb switch.
>
> Both nic's come up in 100 Mb/s - I rebooted the switch, and I plugged
> and unplugged the cables, I tried ethtool -r ethx a few times to no avail.
>
> Other machines on same switch are happily running at full gigabit speeds.
>
> Nothing in logs suggests a problem
>
> Is there a problem with multi nics of same brand where they need to run
> at diff speeds ? Or is this a quirk with some hardware somewhere ? Or ???
>
>
Unlikely.
We use Intel NIC's (both 1GbE and 10GbE) extensively (up to 16 linkes
per machine) for link monitoring without issues.
> Appreciate any suggesions ... its getting tiring forcing renogiation!
Try connecting the two links to each other.
Set their respective IP's to 1.1.1.1/255.255.255.0 (eth1) and
2.2.2.2/255.255.255.0 (eth2).
Now, check that they both auto negotiate to 1GbE/Full duplex.
If they don't, you have a wire issue. (Is it CAT 5 or above?)
If they do, do the following:
1. Install iptraf. ($ yum install iptraf -y)
2. Launch iptrag and configure it to work in promiscuous mode (Configure
-> Force promiscuous mode).
3. Go back, select the "general interface statistics".
4. From another console, start flood pinging.
ping -s 1400 -f -i eth2 -b 1.1.1.255
5. Return to the iptraf console, you should the see the packet increase
linearly on both interfaces. If it doesn't, something is broken, if it
does - you have a switch problem.
- Gilboa
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