FC6 Networking problems

[clarkus978]

I posted this same problem in a different thread...but I thought I would start a new thread. I've got two NIC cards with static IP's (which I know they are configured correctly, because they have the same IP settings I used when I was running FC3) but now I don't have internet and the bridge I've created between my server and workstation don't talk. I can't even ping my FC6 servers NIC. I shut off SELinux because I read in a different thread its necessary if you want vsftp to be running correctly. The computer is running very slow and the internet is slow. I'm running an AMD Athlon 1.1Ghz with 512MB RAM. Both NIC cards are Netgear 10/100. Please help! Thanks

[Brian1]

So you are saying one nic is connected to the internet and the other is used on the lan side. Then network masquerading is used to allow lan side nic machines to connect to the internet.
Is this correct?

As far as slow it could be a number of things. If one nic is removed then is the performance fine?
If so then it could be a bugging module for the nic. I have seen this happen when using the same brand and model of nics. Usually it this is resolved on the next kernel release if caught.

Antother thought is if use the NetworkManager service then this could cause havoc on a system if two nics are setup incorrect.

Post contents of /etc/sysconfig/network-scripts ifcfg-eth0 and ifcfg-eth1.

Before going further lets make sure the first part of this post is what you are setting up.

[clarkus978]

Ok, Ok...so I believe my server is fast. Some programs are just slow because I have yet to install the nvidia drivers. So that's another issue...

My internet is just slow and it seems to take forever for FF to load. Here are the details from my ifcfg-eth0 and ifcfg-eth1:

# ADMtek NC100 Network Everywhere Fast Ethernet 10/100
DEVICE=eth0
BOOTPROTO=none
BROADCAST=<xx.xx.xxx.x> External IP
HWADDR=00:04:5a:4c:ae:08
IPADDR=192.168.0.2
NETMASK=255.255.255.0
NETWORK=192.168.0.0
ONBOOT=yes
GATEWAY=192.168.0.1
TYPE=Ethernet
USERCTL=no
IPV6INIT=no
PEERDNS=yes

# Lite-On Communications Inc LNE100TX
DEVICE=eth1
BOOTPROTO=none
HWADDR=00:a0:cc:5a:46:09
ONBOOT=yes
DHCP_HOSTNAME=holla.homeip.net
IPADDR=192.168.1.1
NETMASK=255.255.255.0
GATEWAY=192.168.0.1
TYPE=Ethernet
USERCTL=no
IPV6INIT=no
PEERDNS=yes

[Brian1]

First thing I see is rem out the line for the gateway for eth1 nic. It can't route that way from the file itself. Leave out the gateway itself and let ipmasquerading handle the routing for itself.

Bring both nics down and flush the iptables. Briang up nic one first and test internet. If good then bring up the second nic and test internet again. If all is good then enable ip_forwad and iptables masquerading commands and check internet one more time. If good then goto the lan machine and test it.

Bring nics down as root.
/sbin/ifdown eth0
/sbin/ifdown eth1

Bring nics up.
/sbin/ifup eth0
/sbin/ifup eth1

Brian

[Iron_Mike]

Looks like you have a routing problem. You have 2 different "private" networks, 192.168.0.1 and 192.168.1.1 correct.??? And you want to route all traffic from the 1.1 to 0.1 network. So you need to route all traffic from eth1 to eth0:

Open a terminal window and switch to root (su -) and type:

route add -net 192.168.1.1 netmask 255.255.255.0 dev eth0
route add -net 192.168.0.1 netmask 255.255.255.0 dev eth1

Your telling IP address 1.1 to route all traffic through eth0 which is your 0.1 ip address this is for the box with the 2 nics. Now for your workstation, setup your ip to 192.168.1.xxx and gateway to 192.168.1.1, primary DNS to 192.168.1.1 and secondary dns to one of your isp or other available dns servers....

[clarkus978]

Originally Posted by Iron_Mike

Looks like you have a routing problem. You have 2 different "private" networks, 192.168.0.1 and 192.168.1.1 correct.??? And you want to route all traffic from the 1.1 to 0.1 network. So you need to route all traffic from eth1 to eth0:

Open a terminal window and switch to root (su -) and type:

route add -net 192.168.1.1 netmask 255.255.255.0 dev eth0
route add -net 192.168.0.1 netmask 255.255.255.0 dev eth1

Your telling IP address 1.1 to route all traffic through eth0 which is your 0.1 ip address this is for the box with the 2 nics. Now for your workstation, setup your ip to 192.168.1.xxx and gateway to 192.168.1.1, primary DNS to 192.168.1.1 and secondary dns to one of your isp or other available dns servers....

Ah yes, makes sense. I remember doing this 3 years ago. It's just been so long since I've set this stuff up. I'm sure that will do the trick. Thanks!

[clarkus978]

Originally Posted by Brian1

First thing I see is rem out the line for the gateway for eth1 nic. It can't route that way from the file itself. Leave out the gateway itself and let ipmasquerading handle the routing for itself.

Bring both nics down and flush the iptables. Briang up nic one first and test internet. If good then bring up the second nic and test internet again. If all is good then enable ip_forwad and iptables masquerading commands and check internet one more time. If good then goto the lan machine and test it.

Bring nics down as root.
/sbin/ifdown eth0
/sbin/ifdown eth1

Bring nics up.
/sbin/ifup eth0
/sbin/ifup eth1

Brian

I flushed the iptables and brought up eth0, the first NIC, and I'm still unable to get to the internet. I know my netgear router is setup properly...because I'm using the wireless off from it on my laptop. Is there another step to this? I also tried Iron_Mike's commands and FC6 didn't like it. It came back with "route: netmask doesn't match route address."

[Iron_Mike]

Open a terminal window and change to root (su -) type:

route

and post the results here.....

[clarkus978]

My internet works now! I found out that when I upgraded to FC6 it changed the names of my NIC cards. Eth0 is now Eth1 ...so I just swapped the cables. I'm still unable to connect to the internet through my workstation. I know I need to enable the port forwarding, but I don't know the commands to do so. Anyways, here's what displays after typing route:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.0 * 255.255.255.0 U 0 0 0 eth0
default 192.168.0.1 0.0.0.0 UG 0 0 0 eth0

[Brian1]

Glad to see you got it going. For the swap of nic labels I guess maybe the kernel change the way IRQ is determined. There are a few ways in the kernel IRQ polling can be done.

Brian