Networking: Gentoo PC -> Fedora F12 PC, for LAN and Internet

[muadib25]

Greetings!

I want to connect my newly created Gentoo DAW to a Fedora 12 PC, for file sharing and Internet purposes.

The Fedora PC has 2 NICs, where one of them is connected to the apartment's Router.
The Gentoo PC has 1 NIC. I am using a crossover Ethernet cable for connecting them.

[UPDATE]

I changed to crossover cable, now my two machines are able to ping each other!

Here's the IPs:
PC1(Gentoo): 192.168.1.2
PC2(Fedora): 192.168.1.3 --- PC2(Fedora) to Router IP: 192.168.0.10
Router's IP: 192.168.0.1

All I need now is for PC1 to enter the internet...
How do I proceed from this point?


Thank you in advance!
Kle

[NeddySeagoon]

muadib25,

You need IP4 packet forwarding turned on on the Fedora box.
Look at /proc/sys/net/ipv4/ip_forward if thats missing, you need to rebuild the kernel.

[muadib25]

Hello!

Ok, IP4 packet forwarding is ON.

I also tried "route add -net 192.168.1.0 netmask 255.255.255.0 gw 192.168.0.1 dev eth2"

where the last IP is the Router's IP. But it returns an error: SIOCADDRT: No such process

I guess 'route' command is a universal Gnu/Linux one, right?


Best Regards,
Kle

[NeddySeagoon]

muadib25,

Yep, route is universal but Fedora may have patched it.
The error message will have shown you the route command syntax - check your syntax.

What is the output of route on the Fedora box?

The gentoo box will also need a default static route.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[muadib25]

Yes, it says on 'man route' notes: "This program is obsolete. For replacement check ip route."

Now, ip route gives the following:

192.168.1.0/24 dev eth2 proto kernel scope link src 192.168.1.3
192.168.0.0/24 dev eth1 proto kernel scope link src 192.168.0.10
169.254.0.0/16 dev eth2 scope link metric 1002
169.254.0.0/16 dev eth1 scope link metric 1003
default via 192.168.0.1 dev eth1


Any clues on how I should route the Gentoo box, too?

Btw, I have to say here that I am a novice in networking, but I guess that's obvious.

[NeddySeagoon]

muadib25,

That tells me that Fedora is using iproute2, which is a more capable replacement for route, ifconfig and friends.
Gentoo provides it too but its not the default in in the stage3 and I've never needed its new capabilities, so I don't know its syntax.

On the gentoo box, you need an IP address for the box and and a default route that points to the next hop towards the internet.
The next hop is either the fedora box or your router, depending on exactly what the fedora box does.

I'm not a network expert either. You seem to know, or are able to find out, some commands, so that moves you out of the novice bracket.

You may need to run tcpdump on the fedora box so we can see whats happening to packets from the gentoo box.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

[muadib25]

Well, I must have done something silly, and now, whenever I re-initialize the networks ( /etc/init.d/network restart ), I don't have internet but I have LAN between the two machines. Now, when I do 'dhclient', Internet comes back, but the LAN fails...

I guess that moves me back to the novice league!

I also noticed something interesting:

When I do the '/etc/init.d/network restart' command, route gives this:


Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.10 * 255.255.255.255 UH 0 0 0 eth2
192.168.1.0 * 255.255.255.0 U 1 0 0 eth2
192.168.0.0 * 255.255.255.0 U 0 0 0 eth1
link-local * 255.255.0.0 U 1002 0 0 eth2
link-local * 255.255.0.0 U 1003 0 0 eth1
default 192.168.0.10 0.0.0.0 UG 0 0 0 eth2

When I do 'killall dhclient' and 'dhclient', route gives this:

192.168.0.0 * 255.255.255.0 U 0 0 0 eth1
default 192.168.0.1 0.0.0.0 UG 0 0 0 eth1


P.S.: If you think I shouldn't be posting all this here, please say so. I don't want to be a nuisance in the forum!

[muadib25]

Never mind, I fixed this last one. A config file flag was changed somehow...

So back where we were:

I let PING on Gentoo pinging Fedora, and 'tcpdump -i eth2' returns:

cpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth2, link-type EN10MB (Ethernet), capture size 65535 bytes
16:02:38.267815 ARP, Request who-has amon-thranduil tell localhost, length 28
16:02:38.267883 ARP, Reply amon-thranduil is-at 00:0b:6a:91:ef:03 (oui Unknown), length 46
16:02:38.276333 IP amon-thranduil > localhost: ICMP echo request, id 19281, seq 397, length 64
16:02:38.276423 IP localhost > amon-thranduil: ICMP echo reply, id 19281, seq 397, length 64
16:02:39.277810 IP amon-thranduil > localhost: ICMP echo request, id 19281, seq 398, length 64

[NeddySeagoon]

muadib25,

Thats odd, lets look at what your routing table means:-

[muadib25]

These are Fedora's ETHx devices:

Eth0--> Doesn't exist
Eth1 --> Fedora to Router
Eth2--> Fedora to Gentoo

Btw, Fedora's ROUTE outputs the following:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 * 255.255.255.0 U 0 0 0 eth2
192.168.0.0 * 255.255.255.0 U 0 0 0 eth1
link-local * 255.255.0.0 U 1002 0 0 eth2
link-local * 255.255.0.0 U 1003 0 0 eth1
default 192.168.0.1 0.0.0.0 UG 0 0 0 eth1


And Gentoo's ROUTE outputs this:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 * 255.255.255.0 U 0 0 0 eth0
loopback * 255.0.0.0 U 0 0 0 lo

[NeddySeagoon]

muadib25,

And Fedora works to the internet and the Gentoo box and Gentoo can reach the Fedora box but no further.

Gentoo now needs a default route, so it knows how to deal with packets that do not match 192.168.1.0/24
The gw will either be the IP of your fedora box, that is connected to Gentoo or your router, I'm not sure.

I guess that your gentoo /etc/resolv.conf is empty?
It needs to be the same as the fedora /etc/resolv.conf as that is what makes name resolution work.

[muadib25]

For starters, I don't know what exactly to type as a ROUTE command on the Gentoo box...

is '"route add -net 192.168.1.0 netmask 255.255.255.0 gw 192.168.0.10 dev eth0"' correct?


192.168.0.10 is Fedora's IP on eth1
192.168.0.1 is Fedora's Gateway.

and
192.168.1.3 is Fedora's IP on eth2.

[muadib25]

I did on Gentoo 'route add -net 192.168.0.0 netmask 255.255.255.0 gw 192.168.1.3 dev eth0'.

Now I can ping the router!!

Resolv.conf is the same on both machines, however Gentoo still can't see the world...

Gentoo's ROUTE says:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 * 255.255.255.0 U 0 0 0 eth0
192.168.0.0 * 192.168.1.3 UG 0 0 0 eth0
loopback * 255.0.0.0 U 0 0 0 lo

[muadib25]

I think I did it!

I edited /etc/conf.d/net and added the line:

routes_eth1=( "default via 192.168.1.3" "10.0.0.0/8 via 192.168.1.3" "::/0")


The thing is that I just found them commented inside the '/etc/conf.d/net' file...

So, from the Gentoo side everything is ok! I can see both the Fedora PC and he router, and I can ping Google.


I keep having some problems with Fedora, though, propably something I did before. Whenever I boot, I have to 'killall dhclient', 'dhclient', and 'ifup eth2' for everything to work...So I think I will have to put these in a script at boot, or ask the Fedora forum about it...

[Hu]

Could you provide the output of ip route show on the Fedora machine both before and after your sequence of killing and restarting the DHCP client? My guess is that the way you have configured it is mangling the routes, and that resetting dhclient causes it to fix the routes. It may also be helpful if you can provide the contents of the Fedora network configuration file (their counterpart to /etc/conf.d/net).

Though we can try to help you here, you might have faster luck with the Fedora forum. At this point, your problem has simplified down to getting a Fedora-based home router to serve both Internet and LAN at once. If you ask on the Fedora forum for help, be sure to mention home router somewhere in the problem description. That will likely draw the attention of the people most qualified to help you.

[bus_drivr]

After puzzling thru this it is unclear to me if you should ipforward or bridge. Either would work I think.
so Gentoo is on eth2 and Fedora and the gw are on eth1? and eth0 doesn't exist?

if so Fedora is going to need to bridge or forward to eth1 the Gentoo packets to/from eth2

Seems a mess unless one is on a DMZ or firewalling/proxying the other. In that case seems better to let the router/gw handle it

[muadib25]

Absolutely! Thank you for the help.

First of all, the sequence is: 'killall dhclient', 'dhclient', 'ifup eth1', 'ifup eth2'.

Secondly, 'ip route show' gives this before:

192.168.1.0/24 dev eth2 proto kernel scope link src 192.168.1.1
192.168.0.0/24 dev eth1 proto kernel scope link src 192.168.0.10 metric 1


and after the killing-resurrecting sequence:

192.168.1.0/24 dev eth2 proto kernel scope link src 192.168.1.3
192.168.0.0/24 dev eth1 proto kernel scope link src 192.168.0.10
169.254.0.0/16 dev eth2 scope link metric 1002
169.254.0.0/16 dev eth1 scope link metric 1003
default via 192.168.0.1 dev eth1


So, I have to find a way to make these permanent, I guess...

About the Fedora-style /etc/conf.d/net, these are oriented per-device, '/etc/sysconfig/network-scripts/ifcfg-eth1':

DEVICE=eth1
BOOTPROTO=dhcp
HWADDR=00:E0:7D:B8:A7:D1
ONBOOT=yes
TYPE=Ethernet
NM_CONTROLLED=yes
USERCTL=yes
GATEWAY=192.168.0.1
IPV6INIT=no
DEFROUTE=yes
IPV6_AUTOCONF=yes
IPV6_DEFROUTE=yes
NAME="System eth1"
UUID=9c92fad9-6ecb-3e6c-eb4d-8a47c6f50c04
IPV6_PEERDNS=yes
IPV6_PEERROUTES=yes
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
PEERDNS=yes
PEERROUTES=yes

and '/etc/sysconfig/network-scripts/ifcfg-eth2':

DEVICE=eth2
IPADDR=192.168.1.3
BOOTPROTO=static
NETMASK=255.255.255.0
TYPE=Ethernet
HWADDR=00:01:29:F2:7F:1F
NETWORK=192.168.1.0
BROADCAST=192.168.1.255
NM_CONTROLLED=yes
IPV6INIT=no
ONBOOT=yes
GATEWAY=192.168.0.10
USERCTL=yes
DEFROUTE=yes
NAME="System eth2"
UUID=3a73717e-65ab-93e8-b518-24f5af32dc0d
PREFIX=24
IPV4_FAILURE_FATAL=yes
IPV6INIT=no

As for my home Router, it is an external Cisco. Sorry if you understood otherwise, all I want to achieve here is for my Fedora box to be as a Gateway for my Gentoo box, because the router is 15 meters away, and I already have one cable coming from there!

Best regards,
Kle

[Hu]

Regarding the route output, that confirms my suspicion that resetting dhclient causes it to clean up the routes. If you configure the Fedora system not to start the eth2 NIC at all and then reboot, do the Internet-related routes get set correctly? If so, I would suspect that there is some ordering issue causing the bringup of eth2 to remove critical routes that dhclient added for eth1.

[muadib25]

[Hu]

That is weird. Either you did not shut off the eth2 startup completely or the Fedora scripts are doing something odd. The eth2 interface should have been down, had no address, and therefore no routes associated with the eth2 network.

[muadib25]

True. Anyway, I'll try to read more into Fedora Networking, just in case I'm missing something (and I am sure I am, LOL)

I'll get back to it with more news to share.