[SOLVED] Slackware router

Richard Cranium · 06-10-2010, 06:28 PM

What does

Code:

/sbin/route -n

tell you?

theNbomr · 06-10-2010, 06:57 PM

Umm, I think you're now going backward. If the host was working as a DHCP client (most installations get this correct, right away), then no need to undo that part. The DHCP aspect to which I referred in an earlier post was the DHCP server, which most installers know nothing about, and which I understood to be part of your objective to set up. Did I get that part wrong?

--- rod.

lpallard · 06-10-2010, 07:07 PM

Rod, you are totally right, my mistake, I got confused between the DHCP assignment for eth0 and the DHCP server running ON eth1 (the one giving IP's to my machines). I will retry with the proper stuff...

Richard, /sbin/route -n gives:

Code:

Kernel IP routing table
Destination        Gateway        Genmask          Flags   Metric   Ref   Use   Iface
99.224.46.0        0.0.0.0        255.255.254.0    U       0        0     0     eth0
127.0.0.0          0.0.0.0        255.0.0.0        U       0        0     0     lo
0.0.0.0            99.224.46.1    0.0.0.0          UG      0        0     0     eth0

acummings · 06-11-2010, 01:17 AM

Quote:

Basically, I have a low end machine sitting between my cable plain modem (no dhcp's etc) and my network switch. I will call this machine the netserver. It has two NIC's. eth0 is connected to the cable modem (red zone) and eth1 is connected to the local network (green zone)

How was it, then, that your eth0 had formerly somehow gotten an IP address?

Once again,

Quote:

(no dhcp's etc)

Are you sure that your ISP doesn't auto assign an IP?

OTOH, some (at least dsl modem some do) modem already act like a router but do so for only one computer.

So you really need to know what your ISP needs you to have/config/setup in order for you to be able to use the internet (eth0 setup).

BTW, FWIW, my earlier idea to use a static IP I had specified "a lan box" (not netserver) so as to troubleshoot your own local network dhcp server you be running on netserver.

Alan.

lpallard · 06-11-2010, 06:41 AM

Hey Allan!

I think the ISP is assigning an IP to a device that request one, either a server (like me) or a simple router.... This is Rogers cable, I just registered and haven't officially received my startup package...!

I think cable is usually static IP, I will have to check if it is static or DHCP (on top of my head, the IP was always something like 99.224.XXX.XXX.... However if I use the dhcp polling to get an IP from the ISP, it works perfectly. If it was a static asignment, would it succeed as well? In other words, can you poll to a static IP assignment using a DHCP?

My cable modem is a Scientific Atlanta (cisco) DPC/EPC2100. I have no idea if the modem request an IP from the ISP, or if the server does...

I guess I will call them and discuss about that.

I'll get back to you soon!

Thanks again!

theNbomr · 06-11-2010, 09:45 AM

I believe most ISPs for residential service use DHCP to provide IPs. If you want a static IP, it is available as part of a more expensive commercial package. In my case, I found that they do provide a 'static' IP name, and it is a convolution of some characters and a string representation of the ethernet MAC associated with the router/firewall/host. So, irrespective of the IP, it is possible to access the site by name (although the name is far from memorable). At least one can embed the IP name in web pages without fear of the name changing over time.
As far as your firewall/router using DHCP, it is probably the case that the DHCP server specifies things like nameserver(s) and routers/gateways. Assigning a static IP is probably a bad idea, as it is more than just the IP that needs to be set, and the ISPs DHCP server can provide this for you. Go back to using a DHCP client on the WAN interface of your firewall.
--- rod.

bgeddy · 06-11-2010, 11:03 AM

I agree with theNbomr here - I use a Scientific Atlanta (cisco) DPC/EPC2100 although my ISP is Virgin media it's setup to offer it's IP's via dhcp. In fact you may usually attach several client boxes to the modem just by attaching a hub as show in the manual here. Each attached box gets it's own IP via dhcp from the modem.

This is not what you are trying to do however - handing out IP addresses to attached clients via a dhcp server on the netserver is your setup and seperate from the Wan attached dhcp assignment. Look at the Wan and Lan sides seperatley i.e. the netserver gets it's Wan IP via dhcp from the modem and then hands out IP addresses to attached Lan clients. It then handles forwarding internet traffic (DNS,url's,etc) for the clients who look at the netserver as their gateway. All the appropriate IP settings for the clients (main IP, gateay IP, DNS IP) are handed out from the netserver via DHCP. It may simplify this setup if you try to think of the WAN side and the LAN sides seperatley with the netserver machine being in the middle and just handling the NAT between the two sides once DHCP IP's are given out via it's DHCP server.

Then you should think about PXE/TFTP serving from the netserver to it's clients but this is further down the line.

There's loads of tutorials for how this all works on line and I recommend studying this as it can get complex quickly! The good part is you will learn a lot about how networks work.

lpallard · 06-11-2010, 11:32 AM

Quote:

I believe most ISPs for residential service use DHCP to provide IPs.

totally true. I called Rogers and asked about this and they said that the modem is programmed to poll a DHCP server from the ISP to get an IP for the machine connected to it. They also confirmed there is no DHCP server ON the modem, so all the machines past the modem are getting an IP from the ISP's DHCP server as well. Basically, I would not need a router if I had only a simple setup, lets say 2 machines ...

Quote:

Look at the Wan and Lan sides seperatley i.e. the netserver gets it's Wan IP via dhcp from the modem and then hands out IP addresses to attached Lan clients

Thats exactly what I think too. Basically, I will continue to get an IP from the WAN side of netserver using a DHCP poll, and assign IP's to my machines using the DHCP server in netserver.

Thats what I have as of now. My machines can get IP's from netserver, netserver can go out on the web, but my machines cannot go out on the web. I believe it is the forwarding that does not work.

bgeddy, I understand what you are saying, it make perfect sense, except this is not working. I am confused if it is my DHCP server's configuration or the forwarding that is non-functional. Richard Cranium (on this thread) asked me for the routes. Please see earlier post. Do you notice anything wrong with the results?

I would like to troubleshoot step by step until I hit something that does not work like it should be... How should I do that? Right now, everything seems normal and working, but it does not work! haha

theNbomr · 06-11-2010, 12:05 PM

Okay, you are mixing up two issues. The clients on the LAN side of your router may or may not be getting served IPs and other parameters from your local DHCP server. That is completely irrespective of routing/firewalling that is performed by the 'netserver'. However, before your LAN clients can access the WAN/internet, they must be correctly configured, and this comes from the DHCP server, as well as individual client configuration. This is part of your stated objective.
The DHCP server must be installed, have a correct configuration file, and be running. If it is running, you should be able to see it in the process list. If it is configured at least partly correctly, it should be emitting messages to the system logs, /var/log/messages. If it is configured fully correctly, it should be dispensing correct IPs to your WAN clients when requested to do so. This will also be evidenced by LAN clients receiving valid IPs and potentially other information.
Start off by identifying which, if any of these are done. Report back with results.
--- rod.

Richard Cranium · 06-11-2010, 02:36 PM

Quote:

Originally Posted by lpallard

My machines can get IP's from netserver, netserver can go out on the web, but my machines cannot go out on the web. I believe it is the forwarding that does not work.

Does

Code:

/etc/rc.d/rc.ip_forward

have the execute bit set? You should read the header of that file if you have not already done so.

lpallard · 06-12-2010, 10:16 PM

Richard, yes ip_forward has the x bit. It is running.

Rod, the DHCP server on the LAN side of netserver seems to be working properly but looking at the /var/log/syslog, I can see some entries that I think might show a problem with my config...

Code:

No subnet declaration for eth1 (0.0.0.0).
** Ignoring requests on eth1.  If this is not what
   you want, please write a subnet declaration
   in your dhcpd.conf file for the network segment
   to which interface eth1 is attached. **
 
Not configured to listen on any interfaces!

my dhcpd.conf file:

Code:

authoritative;
ddns-update-style none;

# Ignore bootp requests:
ignore bootp;

# option definitions common to all configured networks...
option domain-name-servers 192.168.0.100;

subnet 192.168.0.0 netmask 255.255.255.0 {
    option domain-name "mydomain";
    option broadcast-address 192.168.0.100;
    option subnet-mask 255.255.255.0;
    option routers 192.168.0.100;

    pool {
      range 192.168.0.101 192.168.0.107;
      default-lease-time 604800;
      max-lease-time 2419200;
      deny unknown clients;
    }
    pool {
      # Guests
      range 192.168.0.110 192.168.0.115;
      default-lease-time 28800;
      max-lease-time 86400;
      deny known clients;
    }
}

group {
  default-lease-time 604800;
  max-lease-time 1209600;

  #hosts here...... removed to shorten post on LQ...
}

group {
  default-lease-time 86400;
  max-lease-time 172800;
  allow bootp;
  next-server 192.168.0.1;
  use-host-decl-names on;

  if substring (option vendor-class-identifier, 0, 9) = "PXEClient" {
    filename "/slackware-12.2/pxelinux.0";
  }
  else if substring (option vendor-class-identifier, 0, 9) = "Etherboot" {
    filename "/slackware-12.2/kernels/hugesmp.s/bzImage";
  }

  host laptop {
    hardware ethernet yy:yy:yy:yy:yy:yy;
    fixed-address 192.168.0.106;
  }
}

As far as I know, the WAN side is OK, I get an IP from the ISP and everything is working fine. When the LAN side will work, I will address the "in-between" with the forwarding, etc....

theNbomr · 06-13-2010, 01:09 AM

Hmm. Peculiar. Does your LAN side ethernet have a static IP address, and is it an address in the subnet 192.168.0.0/24? I'm not too sure right now what the problem is, so this is a bit of fishing. My thought is that although your DHCP config looks okay, it doesn't know what interface to use, because it doesn't see one that matches the specified subnet.

--- rod.

lpallard · 06-13-2010, 10:34 AM

Hey Rod!

the eth1 on the server is configured as a static IP in /etc/rc.d/rc.inet1.conf with 192.168.0.100 so unless i dont understand the way IP works, yes eth1 is within 192.168.0.0/24...

When i saw this error message in syslog i thought that eth1 was not being activated at boot time by slackware... As far as I know of slackware, if the inteface in configured in inet1.conf, it will be started. both interfaces being configured in inet1.conf, they normally should be started, but just to be sure, I added /etc/rc.d/rc.inet1 eth1_start in rc.local to manually start eth1 at boot time, but with no success.

thanks for your patience Rod! collaboration is the reason why i will not go back to windowz

Gerard Lally · 06-13-2010, 11:03 AM

Quote:

Originally Posted by lpallard

Richard, yes ip_forward has the x bit. It is running.

Rod, the DHCP server on the LAN side of netserver seems to be working properly but looking at the /var/log/syslog, I can see some entries that I think might show a problem with my config...

Code:

No subnet declaration for eth1 (0.0.0.0).
** Ignoring requests on eth1.  If this is not what
   you want, please write a subnet declaration
   in your dhcpd.conf file for the network segment
   to which interface eth1 is attached. **
 
Not configured to listen on any interfaces!

my dhcpd.conf file:

Code:

authoritative;
ddns-update-style none;

# Ignore bootp requests:
ignore bootp;

# option definitions common to all configured networks...
option domain-name-servers 192.168.0.100;

subnet 192.168.0.0 netmask 255.255.255.0 {
    option domain-name "mydomain";
    option broadcast-address 192.168.0.100;
    option subnet-mask 255.255.255.0;
    option routers 192.168.0.100;

    pool {
      range 192.168.0.101 192.168.0.107;
      default-lease-time 604800;
      max-lease-time 2419200;
      deny unknown clients;
    }
    pool {
      # Guests
      range 192.168.0.110 192.168.0.115;
      default-lease-time 28800;
      max-lease-time 86400;
      deny known clients;
    }
}

group {
  default-lease-time 604800;
  max-lease-time 1209600;

  #hosts here...... removed to shorten post on LQ...
}

group {
  default-lease-time 86400;
  max-lease-time 172800;
  allow bootp;
  next-server 192.168.0.1;
  use-host-decl-names on;

  if substring (option vendor-class-identifier, 0, 9) = "PXEClient" {
    filename "/slackware-12.2/pxelinux.0";
  }
  else if substring (option vendor-class-identifier, 0, 9) = "Etherboot" {
    filename "/slackware-12.2/kernels/hugesmp.s/bzImage";
  }

  host laptop {
    hardware ethernet yy:yy:yy:yy:yy:yy;
    fixed-address 192.168.0.106;
  }
}

As far as I know, the WAN side is OK, I get an IP from the ISP and everything is working fine. When the LAN side will work, I will address the "in-between" with the forwarding, etc....

option broadcast-address should be 192.168.0.255

Gerard Lally · 06-13-2010, 11:09 AM

Quote:

Originally Posted by lpallard

Richard, yes ip_forward has the x bit. It is running.

Rod, the DHCP server on the LAN side of netserver seems to be working properly but looking at the /var/log/syslog, I can see some entries that I think might show a problem with my config...

Code:

No subnet declaration for eth1 (0.0.0.0).
** Ignoring requests on eth1.  If this is not what
   you want, please write a subnet declaration
   in your dhcpd.conf file for the network segment
   to which interface eth1 is attached. **
 
Not configured to listen on any interfaces!

my dhcpd.conf file:

Code:

authoritative;
ddns-update-style none;

# Ignore bootp requests:
ignore bootp;

# option definitions common to all configured networks...
option domain-name-servers 192.168.0.100;

subnet 192.168.0.0 netmask 255.255.255.0 {
    option domain-name "mydomain";
    option broadcast-address 192.168.0.100;
    option subnet-mask 255.255.255.0;
    option routers 192.168.0.100;

    pool {
      range 192.168.0.101 192.168.0.107;
      default-lease-time 604800;
      max-lease-time 2419200;
      deny unknown clients;
    }
    pool {
      # Guests
      range 192.168.0.110 192.168.0.115;
      default-lease-time 28800;
      max-lease-time 86400;
      deny known clients;
    }
}

group {
  default-lease-time 604800;
  max-lease-time 1209600;

  #hosts here...... removed to shorten post on LQ...
}

group {
  default-lease-time 86400;
  max-lease-time 172800;
  allow bootp;
  next-server 192.168.0.1;
  use-host-decl-names on;

  if substring (option vendor-class-identifier, 0, 9) = "PXEClient" {
    filename "/slackware-12.2/pxelinux.0";
  }
  else if substring (option vendor-class-identifier, 0, 9) = "Etherboot" {
    filename "/slackware-12.2/kernels/hugesmp.s/bzImage";
  }

  host laptop {
    hardware ethernet yy:yy:yy:yy:yy:yy;
    fixed-address 192.168.0.106;
  }
}

As far as I know, the WAN side is OK, I get an IP from the ISP and everything is working fine. When the LAN side will work, I will address the "in-between" with the forwarding, etc....

option broadcast-address should be 192.168.0.255