Unable to setup fedora as gateway properly

[m6aUdS]

Hi!

I am trying to make my fedora 15 my gateway instead of my old D-Link, but I can't seem to get it working.

Here is my ifconfig

em1 Link encap:Ethernet HWaddr 00:0F:FE:79:28:0D
inet addr:192.168.0.1 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::20f:feff:fe79:280d/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:270089 errors:0 dropped:0 overruns:0 frame:0
TX packets:262100 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:37871486 (36.1 MiB) TX bytes:35214898 (33.5 MiB)
Interrupt:19 Memory:f0500000-f0520000

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:80042 errors:0 dropped:0 overruns:0 frame:0
TX packets:80042 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:22432199 (21.3 MiB) TX bytes:22432199 (21.3 MiB)

p1p2 Link encap:Ethernet HWaddr D8:5D:4C:80:9D:74
inet addr:206.167.183.120 Bcast:206.167.183.255 Mask:255.255.255.0
inet6 addr: fe80::da5d:4cff:fe80:9d74/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:8676 errors:0 dropped:0 overruns:0 frame:0
TX packets:7111 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:8588944 (8.1 MiB) TX bytes:884011 (863.2 KiB)
Interrupt:20 Base address:0x2800

p1p3 Link encap:Ethernet HWaddr 00:A1:B0:00:00:7B
inet6 addr: fe80::2a1:b0ff:fe00:7b/64 Scope:Link
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:35 errors:0 dropped:0 overruns:0 frame:0
TX packets:113 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:5498 (5.3 KiB) TX bytes:36889 (36.0 KiB)
Interrupt:16 Base address:0x1000

wlan0 Link encap:Ethernet HWaddr E0:69:95:44:85:2E
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

As you seen, em1 is my internal interface and p1p2 is my external interface.

Here are my iptables supposed to masquerade:

Chain INPUT (policy ACCEPT)
target prot opt source destination

Chain FORWARD (policy ACCEPT)
target prot opt source destination
ACCEPT all -- anywhere anywhere
ACCEPT all -- anywhere anywhere state RELATED,ESTABLISHED

Chain OUTPUT (policy ACCEPT)
target prot opt source destination

And this my "route -n"

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
206.167.183.250 0.0.0.0 255.255.255.255 UH 0 0 0 em1
206.167.183.0 0.0.0.0 255.255.255.0 U 1 0 0 p1p2
192.168.0.0 0.0.0.0 255.255.255.0 U 1 0 0 em1
0.0.0.0 206.167.183.250 0.0.0.0 UG 0 0 0 em1
0.0.0.0 206.167.183.250 0.0.0.0 UG 0 0 0 p1p2

Problem is:
As soon as I turn on em1, the computer looses the Internet. If em1 is down, Internet is working fine on the box.

Here is my "route -n" with em1 down:

Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
206.167.183.0 0.0.0.0 255.255.255.0 U 1 0 0 p1p2
0.0.0.0 206.167.183.250 0.0.0.0 UG 0 0 0 p1p2

Any idea why my configuration does not work?

[Keldorn]

Hi!

As soon as I turn on em1, the computer looses the Internet. If em1 is down, Internet is working fine on the box.

How you turning in on?

[m6aUdS]

I turn it on with fedora's GUI (up-right of screen) which is shortcut for Network Settings.

in [Options]->[IPv4 Settings] I set:

Method: Manual

Addresses:
Address | Netmask | Gateway
192.168.0.1 | 255.255.255.0 | 0.0.0.0

[Keldorn]

Oh, my...
recheck yours default route after you doing that.

[m6aUdS]

Originally Posted by Keldorn

Oh, my...
recheck yours default route after you doing that.

The routes stay the same as in the example of "route -n" I gave...

Thanks for the hint though...

[m6aUdS]

YEAH I got it!

I followed this thread http://forums.fedoraforum.org/showthread.php?t=225778

The hint was that the network manager was making em1 steal the default route. I just checked 'Use this connection only for resources on its network' in the nm and magic! It work perfectly!

Now I just have to setup a decent firewall ;-)