An elementary question on LANs

[Timothy Murphy]

What exactly sets up the correspondence between interfaces and LANs,
eg (in my case) eth1 <-> 192.168.2.0 ?

I don't see any file in /etc/sysconfig , say,
where this is specified.

-- 
Timothy Murphy  
e-mail: gayleard /at/ eircom.net
tel: [phone]
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland

[Digimer]

On 07/16/2011 02:04 PM, Timothy Murphy wrote:
>  g wrote:
>  
> > so, to op, Timothy Murphy,
> >
> > do you wish to know;
> >
> >  1- what determines mapping of nic [network interface card/chipset] to an
> >   ip address?
>  
>  I assume that this is set in ifcfg-ethX . 
You are right. Either by 'IPADDR=...' or 'BOOTPROTO="dhcp"' and
then
that ethX will get an IP from the DHCP server.

> >  2- what determines mapping of nic [network interface
> card/chipset] to an
> >   ethx position?
>  
>  That is an interesting question.
>  I see that in CentOS-6 there is a file 
>  /etc/udev/rules.d/70-persistent-net.rules
>  which matches interface (ethX) to MAC address.
>  But this file does not seem to be present in CentOS-5.6 .
>  
>  I assume that in CentOS-5.6 the match is set in ifcfg-ethX ;
>  but I'm not sure which of the two is dominant in CentOS-6. 
In EL5 (CentOS 5.x), the only place to do the mapping was using the
HWADDR= setting in the 'ifcfg-ethX' file. In recent Fedora's and in EL6
(CentOS 6.x), it is *also* set in the udev file. I suspect that you
could forgo the 'HWADDR' entry in the ifcfg-ethX files, and let udev be
the sole config location, but I've not tried this. I always keep them
both set.

> >  3- what determines order of mapping of nic [network interface
> >  card/chipset]
> >   to an ip address?
>  
>  I'm not sure what you mean by the _order_ of the mapping?
>  My guess is that in the absence of any action by the user
>  which NIC is assigned to eth0 and which to eth1 (etc)
>  is determined by the position of the NICs in the PCI device table?
>  But I'd be interested to know the answer to this. 
I think g was talking about some corolation between the network card's
physical location on the motherboard and the 'ethX' name. Until
recently, there was no reliable way to determine this. In the most
recent Fedora 15, an attempt is made to provide a mapping. This method
mostly does away with the traditional 'ethX' naming though.

> >  4- what determines order of mapping of nic [network interface
> >  card/chipset]
> >   to an ethx position?
>  
>  I don't see how this differs from the previous question. 
I don't either. :)

> >  5- none of above?
>  
>  I think my question was slightly different to any of the above.
>  I was asking how the connection between an interface (ethX)
>  and a subnet (192.168.2.0) was, or could be, established,
>  since that seems to be what dhcpd wants before it starts. 
DHCP requests go out on 255.255.255.255 iirc. Regardless, you do not
need to specify anything when requesting an IP address from a DHCP
server, beyond telling ifcfg-ethX to use DHCP in the first place.

>  My problem basically is the error message
>  ------------------------------------
>  alfred dhcpd: No subnet declaration for eth1 (no IPv4 addresses).
>  alfred dhcpd: ** Ignoring requests on eth1.  If this is not what
>  alfred dhcpd:    you want, please write a subnet declaration
>  alfred dhcpd:    in your dhcpd.conf file for the network segment
>  alfred dhcpd:    to which interface eth1 is attached. **
>  alfred dhcpd:
>  alfred dhcpd:
>  alfred dhcpd: Not configured to listen on any interfaces!
>  ------------------------------------ 
OOOOhhhhh, you're trying to configure a DHCP server itself! I see.

This may or may not help;

http://wiki.alteeve.com/index.php/DHCP_on_an_RPM-based_OS

As for which interfaces are used to listen for requests, take a boo at
this part from the DHCP daemon's man page (man dhcpd):

===
The names of the network interfaces on which dhcpd should listen for
broadcasts may be specified on the command line.  This should be done on
systems where dhcpd is unable to identify  non-broadcast  interfaces,
but  should  not  be required on other systems.  If no interface names
are specified on the command line dhcpd will identify all network
interfaces which are up, eliminating non-broadcast interfaces if
possible, and listen for DHCP broadcasts on each interface.
===

>  It seems that dhcpd requires that a connection should have been
> established
>  between eth1 and the subnet 192.168.2.0 _before_ dhcpd starts.
>  
>  I have a subnet declaration for the subnet 192.168.2.0
>  in /etc/dhcpd.conf :
>  ------------------------------------
>  subnet 192.168.2.0 netmask 255.255.255.0 {
>  
>          authoritative;
>  
>  # --- default gateway
>          option routers                  192.168.2.1;
>          option subnet-mask              255.255.255.0;
>  
>  #       option nis-domain               "gayleard.com";
>          option domain-name              "gayleard.com";
>          option domain-name-servers      208.67.222.222,208.67.220.220;
>  
>          range 192.168.2.100 192.168.2.250;
>          range dynamic-bootp 192.168.2.128 192.168.2.254;
>  
>          host alfred {
>                  hardware 00:1B:21:AB:C9:4C;
>                  fixed-address 192.168.2.2;
>          }
>  ...
>  }
>  ------------------------------------
>  
>  Also ifconfig contains
>  
>  eth1      Link encap:Ethernet  HWaddr 00:1B:21:AB:C9:4C  
>            inet addr:192.168.2.2  Bcast:192.168.2.255  Mask:255.255.255.0
>  
>  But it seems this is not sufficient to establish 
>  "a subnet declaration for eth1".
>  
>  I tried adding an empty declaration for 192.168.1.0 ,
>  and also (as was suggested) sandwiching the subset declartion(s) in
>  shared-network opt {
>  ...
>  }
>  but neither seemed to make any difference.
>  
>  If anyone can tell me what I am missing I should be very grateful.
>    
>
> http://wiki.alteeve.com/index.php/Changing_the_ethX_to_Ethernet_Device_Ma...
> >
> > is a  good read.
>  
>  I did look at this, but it did not seem relevant to my problem. 
It was not. The initial impression most of us got was that the problem
you were having was with the basic network card setup. You did not
indicate that you were configuring a DHCP server. :)

-- 
Digimer
E-Mail:              digimer(a)alteeve.com
Freenode handle:     digimer
Papers and Projects: http://alteeve.com
Node Assassin:       http://nodeassassin.org
"At what point did we forget that the Space Shuttle was, essentially,
a program that strapped human beings to an explosion and tried to stab
through the sky with fire and math?"

[g]

On 07/16/2011 06:04 PM, Timothy Murphy wrote:
>  g wrote:
>  
> > so, to op, Timothy Murphy,
> >
> > do you wish to know;
> >
> >  1- what determines mapping of nic [network interface card/chipset] to an
> >   ip address?
>  
>  I assume that this is set in ifcfg-ethX . 
http://tldp.org/LDP/solrhe/Securing-Optimizing-Linux-RH-Edition-v1.3/chap...

which is starts from;

http://tldp.org/LDP/solrhe/Securing-Optimizing-Linux-RH-Edition-v1.3/file...

This chapter deals with all the basic files usually text files related to
TCP/IP networking.It's very important to know the configurations files
related to TCP/IP networking, so that you can edit and configure the files
if necessary. Remember that our server doesn't have an Xwindow interface to
configure files via graphical interface. Even if you use a GUI in your daily
activities it is important to know how to configure network in text mode.
The following sections describe the basic TCP/IP configuration files.


> >  2- what determines mapping of nic [network interface
> card/chipset] to an
> >   ethx position?
>  
>  That is an interesting question. 

in addition;

http://tldp.org/LDP/solrhe/Securing-Optimizing-Linux-RH-Edition-v1.3/chap...

You can use Linux as a gateway between two Ethernet networks. In that case,
you might have two Ethernet cards on your server. To eliminate problems at
boot time, the Linux kernel doesn't detect multiple cards automatically.
If you happen to have two or more cards, you should specify the parameters
of the cards in the lilo.conf file for a monolithic kernel or in the
conf.modules file for a modularized kernel. The following are problems you
may encounter with your network cards.

<>

> >  3- what determines order of mapping of nic [network interface
> >  card/chipset] to an ip address?
>  
>  I'm not sure what you mean by the _order_ of the mapping?
>
>  My guess is that in the absence of any action by the user
>  which NIC is assigned to eth0 and which to eth1 (etc)
>  is determined by the position of the NICs in the PCI device table?
>  But I'd be interested to know the answer to this. 
correct. if you have an 'onboard chipset' and 'pci cards', 'pci
cards'
will take precedence over 'onboard chipset'.

<>

>  I don't see how this differs from the previous question.
>
> >  5- none of above?
>  
>  I think my question was slightly different to any of the above. 
actually, i was taking basic of your 1st post and throwing out possible
variations of what you might have meant by the nebulous. :)


a lot of informative information can be found at;

  http://tldp.org/index.html

their searches are run via google and a lot of what you are asking about
can be found there.

they also have a nice wiki;

  http://wiki.tldp.org/

<>

>  Also ifconfig contains 
http://www.google.com/cse?cx=017644269519104757279%3Agm62gtzaoky&q=if...

<>

> http://wiki.alteeve.com/index.php/Changing_the_ethX_to_Ethernet_Device_Ma...
> > is a  good read.
>  
>  I did look at this, but it did not seem relevant to my problem. 
as i said, "is a  good read". ;)


a lot of '<>' trimming is because a lot of what you are stating is covered
in 'tldp' links.


a few more links to info;

  http://tldp.org/LDP/nag2/index.html
  http://www.linuxhomenetworking.com/
  http://www.networkworld.com/
  http://www.yolinux.com/TUTORIALS/LinuxTutorialNetworking.html


when you get tired of all the reading links, you can check this link;

  http://www.cartoonnetwork.com/


happy reading.

hth.
-- 

peace out.

tc.hago,

g
.

****
in a free world without fences, who needs gates.
**
help microsoft stamp out piracy - give linux to a friend today.
**
to mess up a linux box, you need to work at it.
to mess up an ms windows box, you just need to *look* at it.
**
The installation instructions stated to install Windows 2000 or better.
So I installed Linux.
**
learn linux:
'Rute User's Tutorial and Exposition' http://rute.2038bug.com/index.html
'The Linux Documentation Project' http://www.tldp.org/
'LDP HOWTO-index' http://www.tldp.org/HOWTO/HOWTO-INDEX/index.html
'HowtoForge' http://howtoforge.com/
****

[Timothy Murphy]

Reindl Harald wrote:

>  this here is dhcpd under Fedora 15 and works the same way
>  like 10 years ago - i guess you did not realize that
>  "dhcpd.conf" is in recent releases located under
>  "/etc/dhcp/dhcpd.conf" and not directly in /etc/
>  and playing the whole time with a ignored config-file 
Thank you very much.
That was indeed my problem.
All the changes I made to /etc/dhcpd.conf were completely ignored,
and the complaints from dhcpd referred to the empty /etc/dhcp/dhcpd.conf
which I did not realise existed.

Now I have transferred /etc/dhcpd.conf to /etc/dhcp/
dhcpd is starting without complaint,
and I can run CentOS-6 on my home servers.

I guess I learned quite a lot from this fiasco ...

-- 
Timothy Murphy  
e-mail: gayleard /at/ eircom.net
tel: [phone]
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland

[g]

On 07/16/2011 07:03 PM, Digimer wrote:
<>

>  I think g was talking about some corolation between the network
> card's
>  physical location on the motherboard and the 'ethX' name. 
correct.

>  Until recently, there was no reliable way to determine this. In the
> most
>  recent Fedora 15, an attempt is made to provide a mapping. This method
>  mostly does away with the traditional 'ethX' naming though. 
and hopefully, in future it will be worked out.

<>

> > I don't see how this differs from the previous question.
>  
>  I don't either. :) 
bingo.

see my reply to same your reply is to.

<>

>  This may or may not help;
>  
>  http://wiki.alteeve.com/index.php/DHCP_on_an_RPM-based_OS 
either way, it is a good and informative read. in fact, from looking at
your index page, there is a lot of good info at your site.

-- 

peace out.

tc.hago,

g
.

****
in a free world without fences, who needs gates.
**
help microsoft stamp out piracy - give linux to a friend today.
**
to mess up a linux box, you need to work at it.
to mess up an ms windows box, you just need to *look* at it.
**
The installation instructions stated to install Windows 2000 or better.
So I installed Linux.
**
learn linux:
'Rute User's Tutorial and Exposition' http://rute.2038bug.com/index.html
'The Linux Documentation Project' http://www.tldp.org/
'LDP HOWTO-index' http://www.tldp.org/HOWTO/HOWTO-INDEX/index.html
'HowtoForge' http://howtoforge.com/
****

[g]

On 07/16/2011 06:23 PM, Mikkel L. Ellertson wrote:
>  On 07/16/2011 11:32 AM, g wrote:
> > On 07/16/2011 04:21 PM, Mikkel L. Ellertson wrote:
> > <>
>  
> >> If you had read his posts, you would know it was not a guess on my part.
> >
> > now you really are guessing.
>
> > now, guess where. ;)
>
>  LOL 
glad you enjoyed it. i was grinning when i wrote. your reply gave me
a good chuckle.

seems his '07/16/2011 06:04 PM' post shows there was a whole lot of
guessing going on with replies.

at least we all now know for sure what he was wanting to know.

-- 

peace out.

tc.hago,

g
.

****
in a free world without fences, who needs gates.
**
help microsoft stamp out piracy - give linux to a friend today.
**
to mess up a linux box, you need to work at it.
to mess up an ms windows box, you just need to *look* at it.
**
The installation instructions stated to install Windows 2000 or better.
So I installed Linux.
**
learn linux:
'Rute User's Tutorial and Exposition' http://rute.2038bug.com/index.html
'The Linux Documentation Project' http://www.tldp.org/
'LDP HOWTO-index' http://www.tldp.org/HOWTO/HOWTO-INDEX/index.html
'HowtoForge' http://howtoforge.com/
****

[Gabriel Ramirez]

On 07/16/2011 01:04 PM, Timothy Murphy wrote:
>  My problem basically is the error message
>  ------------------------------------
>  alfred dhcpd: No subnet declaration for eth1 (no IPv4 addresses).
>  alfred dhcpd: ** Ignoring requests on eth1.  If this is not what
>  alfred dhcpd:    you want, please write a subnet declaration
>  alfred dhcpd:    in your dhcpd.conf file for the network segment
>  alfred dhcpd:    to which interface eth1 is attached. **
>  alfred dhcpd:
>  alfred dhcpd:
>  alfred dhcpd: Not configured to listen on any interfaces!
>  ------------------------------------ 
maybe you need to edit:

/etc/sysconfig/dhcpd

and put
DHCPDARGS="eth1"
so dhcpd listen in interface eth1

or by example

DHCPDARGS="eth0 eth1"

if you need more interfaces served by dhcpd, adjust them as necessary

Gabrielo

[Digimer]

On 07/16/2011 02:24 PM, Timothy Murphy wrote:
>  Digimer wrote:
>  
> > On 07/15/2011 03:00 PM, Timothy Murphy wrote:
> >> What exactly sets up the correspondence between interfaces and LANs,
> >> eg (in my case) eth1 <-> 192.168.2.0 ?
> >>
> >> I don't see any file in /etc/sysconfig , say,
> >> where this is specified.
> >
> > It's mapped using 'HWADDR' in the
> > /etc/sysconfig/network-scripts/ifcfg-ethX and/or in
> > /etc/udev/rules.d/70-persistent-net.rules.
>  
>  These establish a correspondence between the interfaces
>  and the MAC addresses of the NICs.
>  And ifcfg-ethX sets up a correspondence between MAC addresses
>  and IP addresses of the NICs,
>  in my case eth1 -> 192.168.2.2 .
>  
>  It would be possible to deduce from this that eth1 corresponds
>  to the subnet 192.168.2.0 .
>  But dhcpd does not appear to make this deduction.
>  
>  If I might ask, are you running dhcpd under CentOS-6 ?
>  Is anybody running dhcpd under CentOS-6 ?
>  If so, I would be very interested to see your dhcpd.conf
>  and ifcfg-ethX .
>  
>  I should say that dhcpd ran (and is running) perfectly
>  under CentOS-5.6 , but not under CentOS-6. 
I have not yet moved my dhcpd servers to CentOS 6. Actually, nothing
outside the lab uses EL6. :)

-- 
Digimer
E-Mail:              digimer(a)alteeve.com
Freenode handle:     digimer
Papers and Projects: http://alteeve.com
Node Assassin:       http://nodeassassin.org
"At what point did we forget that the Space Shuttle was, essentially,
a program that strapped human beings to an explosion and tried to stab
through the sky with fire and math?"

[Reindl Harald]

Am 16.07.2011 20:24, schrieb Timothy Murphy:
> > It's mapped using 'HWADDR' in the
> > /etc/sysconfig/network-scripts/ifcfg-ethX and/or in
> > /etc/udev/rules.d/70-persistent-net.rules.
>  
>  These establish a correspondence between the interfaces
>  and the MAC addresses of the NICs 
yes, /etc/udev/rules.d/70-persistent-net.rule do this

>  And ifcfg-ethX sets up a correspondence between MAC addresses
>  and IP addresses of the NICs,
>  in my case eth1 -> 192.168.2.2 . 
i would NOT use HWADDR in ifcfg-ethX becasue it is
useless and if you want to change the devices
with /etc/udev/rules.d/70-persistent-net.rules you
have always to look at ifcfg-ethX

DEVICE=ethX is enough in ifcfg-ethX

>  It would be possible to deduce from this that eth1 corresponds
>  to the subnet 192.168.2.0 .
>  But dhcpd does not appear to make this deduction. 
if you want really control what dhcpd provides
you have to set MAC->IP paris in dhcpd.conf

host whatever {
 hardware ethernet 00:90:3E:C8:D0:3C;
 fixed-address 192.168.1.7;
}

>  If I might ask, are you running dhcpd under CentOS-6 ?
>  Is anybody running dhcpd under CentOS-6 ?
>  If so, I would be very interested to see your dhcpd.conf
>  and ifcfg-ethX .
>  
>  I should say that dhcpd ran (and is running) perfectly
>  under CentOS-5.6 , but not under CentOS-6 
this here is dhcpd under Fedora 15 and works the same way
like 10 years ago - i guess you did not realize that
"dhcpd.conf" is in recent releases located under
"/etc/dhcp/dhcpd.conf" and not directly in /etc/
and playing the whole time with a ignored config-file

cat /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
IPADDR=192.168.1.2
NETWORK=192.168.1.0
GATEWAY=192.168.1.1
BROADCAST=192.168.1.255
NETMASK=255.255.255.0
TYPE=Ethernet
BOOTPROTO=static
ONBOOT=yes
NM_CONTROLLED=no
USERCTL=no
IPV6INIT=no
________________

[root@srv-rhsoft:~]$ cat /etc/dhcp/dhcpd.conf
authoritative;
ddns-update-style none;
ddns-updates off;
default-lease-time 86400;
max-lease-time 259200;
log-facility local7;

subnet 192.168.1.0 netmask 255.255.255.0 {
 option domain-name "rhsoft.net";
 option domain-name-servers 192.168.1.2;
 option routers 192.168.1.1;
 option smtp-server 192.168.1.2;
 option pop-server 192.168.1.2;
 option ntp-servers 192.168.1.2;
 option time-servers 192.168.1.2;
 option subnet-mask 255.255.255.0;
 option broadcast-address 192.168.1.255;
 range 192.168.1.150 192.168.1.200;
}

host drucker {
 hardware ethernet 00:17:A4:6E:2E:94;
 fixed-address 192.168.1.10;
}

host telefon {
 hardware ethernet 00:0E:08:DD:9C:FD;
 fixed-address 192.168.1.15;
}

host drucker-eth {
 hardware ethernet 00:17:A4:6E:2E:95;
 fixed-address 192.168.1.14;
}

[Timothy Murphy]

Digimer wrote:

>  On 07/15/2011 03:00 PM, Timothy Murphy wrote:
> > What exactly sets up the correspondence between interfaces and LANs,
> > eg (in my case) eth1 <-> 192.168.2.0 ?
> > 
> > I don't see any file in /etc/sysconfig , say,
> > where this is specified.
>  
>  It's mapped using 'HWADDR' in the
>  /etc/sysconfig/network-scripts/ifcfg-ethX and/or in
>  /etc/udev/rules.d/70-persistent-net.rules. 
These establish a correspondence between the interfaces
and the MAC addresses of the NICs.
And ifcfg-ethX sets up a correspondence between MAC addresses
and IP addresses of the NICs,
in my case eth1 -> 192.168.2.2 .

It would be possible to deduce from this that eth1 corresponds
to the subnet 192.168.2.0 .
But dhcpd does not appear to make this deduction.

If I might ask, are you running dhcpd under CentOS-6 ?
Is anybody running dhcpd under CentOS-6 ?
If so, I would be very interested to see your dhcpd.conf
and ifcfg-ethX .

I should say that dhcpd ran (and is running) perfectly
under CentOS-5.6 , but not under CentOS-6.


-- 
Timothy Murphy  
e-mail: gayleard /at/ eircom.net
tel: [phone]
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland

[Mikkel L. Ellertson]

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Hash: SHA1

On 07/16/2011 11:32 AM, g wrote:
>  On 07/16/2011 04:21 PM, Mikkel L. Ellertson wrote:
>  <>
>  
> > If you had read his posts, you would know it was not a guess on my part.
>  
>  now you really are guessing.
>  
>  now, guess where. ;)
>   
LOL

- -- 
No boom today... boom tomorrow.
There's always a boom tomorrow.
- - Susan Ivanova B5
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[Timothy Murphy]

g wrote:

>  so, to op, Timothy Murphy,
>  
>  do you wish to know;
>  
>   1- what determines mapping of nic [network interface card/chipset] to an
>    ip address? 
I assume that this is set in ifcfg-ethX .

>   2- what determines mapping of nic [network interface card/chipset]
> to an
>    ethx position? 
That is an interesting question.
I see that in CentOS-6 there is a file 
/etc/udev/rules.d/70-persistent-net.rules
which matches interface (ethX) to MAC address.
But this file does not seem to be present in CentOS-5.6 .

I assume that in CentOS-5.6 the match is set in ifcfg-ethX ;
but I'm not sure which of the two is dominant in CentOS-6.

>   3- what determines order of mapping of nic [network interface
>   card/chipset]
>    to an ip address? 
I'm not sure what you mean by the _order_ of the mapping?
My guess is that in the absence of any action by the user
which NIC is assigned to eth0 and which to eth1 (etc)
is determined by the position of the NICs in the PCI device table?
But I'd be interested to know the answer to this.

>   4- what determines order of mapping of nic [network interface
>   card/chipset]
>    to an ethx position? 
I don't see how this differs from the previous question.

>   5- none of above? 
I think my question was slightly different to any of the above.
I was asking how the connection between an interface (ethX)
and a subnet (192.168.2.0) was, or could be, established,
since that seems to be what dhcpd wants before it starts.

My problem basically is the error message
------------------------------------
alfred dhcpd: No subnet declaration for eth1 (no IPv4 addresses).
alfred dhcpd: ** Ignoring requests on eth1.  If this is not what
alfred dhcpd:    you want, please write a subnet declaration
alfred dhcpd:    in your dhcpd.conf file for the network segment
alfred dhcpd:    to which interface eth1 is attached. **
alfred dhcpd:
alfred dhcpd:
alfred dhcpd: Not configured to listen on any interfaces!
------------------------------------

It seems that dhcpd requires that a connection should have been established
between eth1 and the subnet 192.168.2.0 _before_ dhcpd starts.

I have a subnet declaration for the subnet 192.168.2.0
in /etc/dhcpd.conf :
------------------------------------
subnet 192.168.2.0 netmask 255.255.255.0 {

        authoritative;

# --- default gateway
        option routers                  192.168.2.1;
        option subnet-mask              255.255.255.0;

#       option nis-domain               "gayleard.com";
        option domain-name              "gayleard.com";
        option domain-name-servers      208.67.222.222,208.67.220.220;

        range 192.168.2.100 192.168.2.250;
        range dynamic-bootp 192.168.2.128 192.168.2.254;

        host alfred {
                hardware 00:1B:21:AB:C9:4C;
                fixed-address 192.168.2.2;
        }
...
}
------------------------------------

Also ifconfig contains

eth1      Link encap:Ethernet  HWaddr 00:1B:21:AB:C9:4C  
          inet addr:192.168.2.2  Bcast:192.168.2.255  Mask:255.255.255.0

But it seems this is not sufficient to establish 
"a subnet declaration for eth1".

I tried adding an empty declaration for 192.168.1.0 ,
and also (as was suggested) sandwiching the subset declartion(s) in
shared-network opt {
...
}
but neither seemed to make any difference.

If anyone can tell me what I am missing I should be very grateful.
  
http://wiki.alteeve.com/index.php/Changing_the_ethX_to_Ethernet_Device_Ma...
>  
>  is a  good read. 
I did look at this, but it did not seem relevant to my problem.
 

-- 
Timothy Murphy  
e-mail: gayleard /at/ eircom.net
tel: [phone]
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland

[g]

On 07/16/2011 04:21 PM, Mikkel L. Ellertson wrote:
<>

>  If you had read his posts, you would know it was not a guess on my
> part. 
now you really are guessing.

now, guess where. ;)


-- 

peace out.

tc.hago,

g
.

****
in a free world without fences, who needs gates.
**
help microsoft stamp out piracy - give linux to a friend today.
**
to mess up a linux box, you need to work at it.
to mess up an ms windows box, you just need to *look* at it.
**
The installation instructions stated to install Windows 2000 or better.
So I installed Linux.
**
learn linux:
'Rute User's Tutorial and Exposition' http://rute.2038bug.com/index.html
'The Linux Documentation Project' http://www.tldp.org/
'LDP HOWTO-index' http://www.tldp.org/HOWTO/HOWTO-INDEX/index.html
'HowtoForge' http://howtoforge.com/
****

[Mikkel L. Ellertson]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 07/16/2011 10:07 AM, g wrote:
>  On 07/16/2011 01:19 AM, Mikkel L. Ellertson wrote:
>  <>
>  
> > Guys, he wants to know where the IP address is set, not what
> > determines what interface is eth1.
>  
>  another good guess. and nothing wrong with it either.
>  
>  but, before any answers are presented, clarification should be made.
>  
>  
>  so, to op, Timothy Murphy,
>  
>  do you wish to know;
>  
>   1- what determines mapping of nic [network interface card/chipset] to an
>    ip address?
>  
>   2- what determines mapping of nic [network interface card/chipset] to an
>    ethx position?
>  
>   3- what determines order of mapping of nic [network interface card/chipset]
>    to an ip address?
>  
>   4- what determines order of mapping of nic [network interface card/chipset]
>    to an ethx position?
>  
>   5- none of above?
>  
>   
If you had read his posts, you would know it was not a guess on my part.

Mikkel
- -- 

  Do not meddle in the affairs of dragons,
for thou art crunchy and taste good with Ketchup!
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.11 (GNU/Linux)
>
> iEYEARECAAYFAk4hungACgkQqbQrVW3JyMRXYQCfU3/b8s5b6RCOrXpNKcId296m
> aJ8An2gr7pPW0xRL+N08WM2080K9rB3i
> =M2Xg
> -----END PGP SIGNATURE-----

[g]

On 07/16/2011 01:19 AM, Mikkel L. Ellertson wrote:
<>

>  Guys, he wants to know where the IP address is set, not what
>  determines what interface is eth1. 
another good guess. and nothing wrong with it either.

but, before any answers are presented, clarification should be made.


so, to op, Timothy Murphy,

do you wish to know;

 1- what determines mapping of nic [network interface card/chipset] to an
  ip address?

 2- what determines mapping of nic [network interface card/chipset] to an
  ethx position?

 3- what determines order of mapping of nic [network interface card/chipset]
  to an ip address?

 4- what determines order of mapping of nic [network interface card/chipset]
  to an ethx position?

 5- none of above?


which ever it is,

http://wiki.alteeve.com/index.php/Changing_the_ethX_to_Ethernet_Device_Ma...

is a  good read.

-- 

peace out.

tc.hago,

g
.

****
in a free world without fences, who needs gates.
**
help microsoft stamp out piracy - give linux to a friend today.
**
to mess up a linux box, you need to work at it.
to mess up an ms windows box, you just need to *look* at it.
**
The installation instructions stated to install Windows 2000 or better.
So I installed Linux.
**
learn linux:
'Rute User's Tutorial and Exposition' http://rute.2038bug.com/index.html
'The Linux Documentation Project' http://www.tldp.org/
'LDP HOWTO-index' http://www.tldp.org/HOWTO/HOWTO-INDEX/index.html
'HowtoForge' http://howtoforge.com/
****

[Mikkel L. Ellertson]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

On 07/15/2011 07:09 PM, Timothy Murphy wrote:
>  Digimer wrote:
>  
> >> What exactly sets up the correspondence between interfaces and LANs,
> >> eg (in my case) eth1 <-> 192.168.2.0 ?
> >>
> >> I don't see any file in /etc/sysconfig , say,
> >> where this is specified.
> >
> > It's mapped using 'HWADDR' in the
> > /etc/sysconfig/network-scripts/ifcfg-ethX and/or in
> > /etc/udev/rules.d/70-persistent-net.rules.
>  
>  As far as I can see, 70-persistent-net.rules just maps
>  each MAC address on a machine to an interface,
>  as also does ifcfg-ethX .
>  
>  Neither seems to me to associate an interface, say eth1,
>  to a LAN, say 192.168.2.0 .
>  
> >
>
> http://wiki.alteeve.com/index.php/Changing_the_ethX_to_Ethernet_Device_Ma...
>  
>  I'll study that, thanks. 
>   
Guys, he wants to know where the IP address is set, not what
determines what interface is eth1.

Now, this could be done a couple of ways. If eth1 is set to get its
information from a DHCP server, then it is not set on your machine
at all, but is given by the DHCP server. If you have a static IP
address, then I would look in
/etc/sysconfig/network-scripts/ifcfg-eth1. You should also have
other configurations in the network-scripts directory. ifcfg-eth0 is
the configuration for eth0.

If you want to know what all the options are, you may want to read
/usr/share/doc/initscripts-9.20.2/sysconfig.txt

Mikkel
- -- 

  Do not meddle in the affairs of dragons,
for thou art crunchy and taste good with Ketchup!
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.11 (GNU/Linux)
>
> iEYEARECAAYFAk4g5wsACgkQqbQrVW3JyMR3TACeMc1BPS3bLYVD9xt0Ax4Kru6Y
> TKsAoIAmATyM+UsOqIjQJA6Kyn6aa5+i
> =hlRf
> -----END PGP SIGNATURE-----

[Timothy Murphy]

Digimer wrote:

> > What exactly sets up the correspondence between interfaces and
> LANs,
> > eg (in my case) eth1 <-> 192.168.2.0 ?
> >   
> > I don't see any file in /etc/sysconfig , say,
> > where this is specified.
>  
>  It's mapped using 'HWADDR' in the
>  /etc/sysconfig/network-scripts/ifcfg-ethX and/or in
>  /etc/udev/rules.d/70-persistent-net.rules. 
As far as I can see, 70-persistent-net.rules just maps
each MAC address on a machine to an interface,
as also does ifcfg-ethX .

Neither seems to me to associate an interface, say eth1,
to a LAN, say 192.168.2.0 .

>  
http://wiki.alteeve.com/index.php/Changing_the_ethX_to_Ethernet_Device_Ma...

I'll study that, thanks. 

-- 
Timothy Murphy  
e-mail: gayleard /at/ eircom.net
tel: [phone]
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland

[Digimer]

On 07/15/2011 03:00 PM, Timothy Murphy wrote:
>  What exactly sets up the correspondence between interfaces and LANs,
>  eg (in my case) eth1 <-> 192.168.2.0 ?
>  
>  I don't see any file in /etc/sysconfig , say,
>  where this is specified. 
It's mapped using 'HWADDR' in the
/etc/sysconfig/network-scripts/ifcfg-ethX and/or in
/etc/udev/rules.d/70-persistent-net.rules.

http://wiki.alteeve.com/index.php/Changing_the_ethX_to_Ethernet_Device_Ma...

-- 
Digimer
E-Mail:              digimer(a)alteeve.com
Freenode handle:     digimer
Papers and Projects: http://alteeve.com
Node Assassin:       http://nodeassassin.org
"At what point did we forget that the Space Shuttle was, essentially,
a program that strapped human beings to an explosion and tried to stab
through the sky with fire and math?"

[Genes MailLists]

On 07/15/2011 03:09 PM, Digimer wrote:
>  On 07/15/2011 03:00 PM, Timothy Murphy wrote:
> > What exactly sets up the correspondence between interfaces and LANs,
> > eg (in my case) eth1 <-> 192.168.2.0 ?
> >
> > I don't see any file in /etc/sysconfig , say,
> > where this is specified.
>  
>  It's mapped using 'HWADDR' in the
>  /etc/sysconfig/network-scripts/ifcfg-ethX and/or in
>  /etc/udev/rules.d/70-persistent-net.rules.
>   
  And in some machines (if not changed elsewhere somehow) biosdevname
may be used - I believe it is now included in F15 ...


   http://fedoraproject.org/wiki/Features/ConsistentNetworkDeviceNaming

  gene