dual port

[ub007]

Hi,

I've got a dual port Nic on my server. I'm using port 1 to push data to my remote box and port 2 for accessing the unit over web interface. But i'm noticing reduced performance when data is being transmitted, so wondering whether data is being pushed through port 2 as opposed to port 1. Is there anyway to find out?
Any linux commands that could help me here?

[Irithori]

man tcpdump

I would use it to monitor the second nic for ports, that are used by the data connections.

[HROAdmin26]

Google and netstat.

If the NIC's are on the same VLAN, you likely don't control which NIC is used unless you have set a specific IP to use in the application.

For NIC's on different VLAN's, NIC selection happens by name resolution - hostname > IP > routing table > NIC selection.

[ub007]

For NIC's on different VLAN's, NIC selection happens by name resolution - hostname > IP > routing table > NIC selection.

NICs are on different VLANS.

netstat -nr:
Kernel IP routing table
Destination Gateway Genmask Flags MSS Window irtt Iface
16.131.152.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
192.168.127.0 0.0.0.0 255.255.255.0 U 0 0 0 eth1
0.0.0.0 16.131.152.1 0.0.0.0 UG 0 0 0 eth0

eth0 is 100Mbps while eth1 is 1G link, does above suggest all traffic is routed through eth0??
and thats reason I find very slow data rates, i was hoping all data will only pass through eth1 and eth0 is just for admin/GUI purposes..

[Irithori]

The default gateway is on eth0,
so any traffic other than the net attached to eth1 (192.168.127.0/24)
will go through eth0

[ub007]

Agree. But is there a way to find which traffic is going to eth1 as well?
my server from which i can administer/access GUI is also on dual port.
is there a way for me to know which port it is using to push data and which port for web?

[HROAdmin26]

But is there a way to find which traffic is going to eth1 as well?

Google and netstat - tcpdump as well.

Re-read what Irithori posted and *understand* it. If the destination of your "data" is NOT on the network 192.168.127.0, the connection will be made using eth0.

[slakumalla]

tcpdump on eth0 can help you in analyzing tx and rx packets perinterface.