Can't get outside through Linux router...

AudioMechanic · 03-15-2005, 07:51 PM

Hello all.

I have ran several searches and spent the past hour and a half reading thread after thread which has helped me get to the point I'm at now.

I have 6 computers (one Mandrake server, 5 nodes running various OS's) but I'll only talk about two seeing as if I can get these two to work, I cdan get the rest of them to work as well.

I am trying to set my Mandrake box up as a server for my other 5 PC's. The PC I'm working with runs XP. The Mandrake box can get on the net (using it to type this now) and ping the XP box. The XP box can get into the Webmin server (http://xxx.xxx.xxx.xxx:10000) on the Mandrake box but cannot ping it (dunno what's up with that) or get to the net. The Mandrake box has two NICs:
eth0 : inside network setup as static
eth1 : internet setup as DHCP

My ISP is cable and I would like my Mandrake box to do NAT. Also, I do have the ISP DNS's listed onthe XP box. The IP of the XP box is 1.1.69.203.

ifconfig

Code:

[root@ip3-119 admin]# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:40:F4:54:AA:C7
          inet addr:1.1.69.100  Bcast:1.1.69.255  Mask:255.255.255.0
          inet6 addr: fe80::240:f4ff:fe54:aac7/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:923 errors:0 dropped:0 overruns:0 frame:0
          TX packets:752 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:131219 (128.1 Kb)  TX bytes:413505 (403.8 Kb)
          Interrupt:10 Base address:0xe000

eth1      Link encap:Ethernet  HWaddr 00:C0:A8:7B:91:99
          inet addr:24.219.206.119  Bcast:24.219.207.255  Mask:255.255.252.0
          inet6 addr: fe80::2c0:a8ff:fe7b:9199/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:16800 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2576 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1933857 (1.8 Mb)  TX bytes:351356 (343.1 Kb)
          Interrupt:11 Base address:0x9000

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:9272 errors:0 dropped:0 overruns:0 frame:0
          TX packets:9272 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:898670 (877.6 Kb)  TX bytes:898670 (877.6 Kb)

[root@ip3-119 admin]#

route -n

Code:

[root@ip3-119 admin]# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
1.1.69.0        0.0.0.0         255.255.255.0   U     0      0        0 eth0
24.219.204.0    0.0.0.0         255.255.252.0   U     0      0        0 eth1
127.0.0.0       0.0.0.0         255.0.0.0       U     0      0        0 lo
0.0.0.0         24.219.204.1    0.0.0.0         UG    0      0        0 eth1
[root@ip3-119 admin]#

/etc/sysconfig/networking/devices/ifcfg-eth0

Code:

BOOTPROTO=none
DEVICE=eth0
MTU=""
NETMASK=255.255.255.0
BROADCAST=1.1.69.255
IPADDR=1.1.69.100
NETWORK=1.1.69.0
MII_NOT_SUPPORTED=no
WIRELESS_ENC_KEY=""
ONBOOT=yes

/etc/sysconfig/networking/devices/ifcfg-eth1

Code:

BOOTPROTO=dhcp
DEVICE=eth1
MTU=""
NEEDHOSTNAME=yes
NETMASK=""
BROADCAST=""
IPADDR=""
MII_NOT_SUPPORTED=no
WIRELESS_ENC_KEY=""
NETWORK=""
ONBOOT=yes

According to everything I have read, I have everything setup correctly. Why can my XP box not get on the net?

mcd · 03-15-2005, 07:54 PM

have you verified that the XP computer is using the right gateway? if you double click on the lan icon in the system tray, select the "support" tab, and click details you should see your gateway listed.

also, why does your XP box have an outside IP address? you're not using a router?

AudioMechanic · 03-15-2005, 08:05 PM

The XP box has in inside IP. My NIC's are backwards: eth0 is the inside interface and eth1 is the outside interface. The inside network is 1.1.69.0.

My DNS's are correct on the XP box. I just double checked them.

Thank you for the reply BTW!! It is much appreaciated. I hope I don't sound mean or rude. I'm just frustrated.

AudioMechanic · 03-15-2005, 08:11 PM

I JUST GOT IT! I had masqerading in my firewall set up wrong!!!!! YYYYYEEEEAAAAAAAAAAA!!!!

No on to the dirty question:
The Mandrake box used to be loaded with Smoothwall Linux and was used exclusively for a network server. I installed Madrake on it hoping I could use it for that and more (print, FTP, fileserver, etc). In smoothwall, I was able to list static IP's for my PC's that connect to the server by MAC address. Can I do that in Mandrake?

My reasoning is that I have a wireless access point (it's not a router, that's what the server's for) and have the security turned off. If I can list the nodes in my network on the server by each NIC's MAC, no one else will be able to connect to my network because I will be impossible for them to grab an IP or even list one themselves without physical access to the server. Any ideas????

benjithegreat98 · 03-15-2005, 08:38 PM

First off you are not using good IP addresses for your internal network. Those are public IP addresses. What happens when you need to get to a website who's IP is 1.1.69.x? Or are you just falsifying them for the purposes of this post. If not they should be one of these:
10.x.x.x
192.168.x.x
172.16.x.x - 172.31.x.x

As for the MAC address thing you could go physically look at each computer and create you mac address control list from there. You can use IPTABLES to block mac addresses. Google for that. There are serveral examples.

AudioMechanic · 03-15-2005, 10:07 PM

The internal addresses for my network are actually true. Hmm...I can chage them pretty easily though. Have had the same IP for my network for about 2 years now and haven't run into a problem yet but I'll change them anyway.

I'll try the MAC address thingie.

Thank you!

benjithegreat98 · 03-15-2005, 10:20 PM

I IP address thing was gotten from an RFC (Request For Comment). RFC 1918 to be exact.
http://www.faqs.org/rfcs/rfc1918.html

RFC's are kinda like the rules of the internet. They're not neccessarily mandantory but if everybody complies w/ them it makes communication easier for everybody.

At work we have a network that uses a public IP range, but we don't know who originally set it up and it would be extremely hard to change. There's equipment on there like CT scanners, XRays, MRI's, etc. It would take too long and we'd have too much down time to even bother.

mcd · 03-15-2005, 10:52 PM

benji - your posts right now number 666...

benjithegreat98 · 03-15-2005, 10:59 PM

BEWARE!!!!! The post of the Beast!!!