Static networking -- nameserver configuration and hostnames

[Jasper Capel]

Hey all,

Currently, it looks like you can't provide an installed system with a 
working resolv.conf, if you're not using DHCP (of course you can snippet 
it).
How about a
cobbler system edit --name=foo.example.com --name-servers="192.168.0.1 
192.168.0.2"?

I also noticed the system's hostname is a property of a network 
interface. Is this intended, or should we make the hostname a property 
of the system? I think this is kind of confusing; although anaconda 
enables you to provide a hostname on each network-line, a system should 
only have one.

Jasper

[Joseph Boyer Jr.]

Jasper,

I would tend to think that the intent of having a host name parameter part of the NIC
configuration is to address the needs of multi-homed machines. At least that is what I use
them for.  In my environment most systems have a public and private interface and I use
the hostname associated with each NIC configuration to properly set up /etc/hosts via
configuration RPM. I use the system name as the "Node name", that is the name
you see when you log into the box or grep HOSTNAME /etc/sysconfig/network.



Joseph Boyer Jr
Enterprise Technology Services
Liquidnet Holdings, Inc.
Joseph.Boyer(a)liquidnet.com
T   +1 646.660.8352
C   +1 646.284.8394


-----Original Message-----
From: cobbler-bounces(a)lists.fedorahosted.org
[mailto:[e-mail]] On Behalf Of Jasper Capel
Sent: Tuesday, October 14, 2008 4:28 PM
To: cobbler mailing list
Subject: Static networking -- nameserver configuration and hostnames

Hey all,

Currently, it looks like you can't provide an installed system with a
working resolv.conf, if you're not using DHCP (of course you can snippet
it).
How about a
cobbler system edit --name=foo.example.com --name-servers="192.168.0.1
192.168.0.2"?

I also noticed the system's hostname is a property of a network
interface. Is this intended, or should we make the hostname a property
of the system? I think this is kind of confusing; although anaconda
enables you to provide a hostname on each network-line, a system should
only have one.

Jasper
_______________________________________________
cobbler mailing list
cobbler(a)lists.fedorahosted.org
https://fedorahosted.org/mailman/listinfo/cobbler

[Jasper Capel]

Joseph Boyer Jr. wrote:
>  Jasper,
>  
>  I would tend to think that the intent of having a host name parameter part of the NIC
> configuration is to address the needs of multi-homed machines. At least that is what I use
> them for.  In my environment most systems have a public and private interface and I use
> the hostname associated with each NIC configuration to properly set up /etc/hosts via
> configuration RPM. I use the system name as the "Node name", that is the name
> you see when you log into the box or grep HOSTNAME /etc/sysconfig/network.
>   
I'm currently doing this as well, but I think we should aim at 
configuring the system's hostname from cobbler (and we easily could, 
with the post_install_network_config snippet). Maybe designating one 
interface as primary and using the hostname from this interface would be 
a nicer alternative than letting anaconda just "pick one"?

Jasper

[Joseph Boyer Jr.]

Ok. I see your issue.

The way I have been getting around this is to add a kickstart option: ksdevice="mac
address of install nic" and or by specifying the kernel parameter: pci=nobfort, which
will disable the old 2.4 NIC enumeration algorithm which is used in 2.6.9-55 or newer
kernels and use the 2.6 nic enumeration algorithm.

Check redhat knowledge base faq: http://kbase.redhat.com/faq/FAQ_46_10460.shtm for more
info.

Dell has also produce a white paper on the NIC enumeration issue:
http://linux.dell.com/files/whitepapers/nic-enum-whitepaper-v3.pdf

--joe

Joseph Boyer Jr
Enterprise Technology Services
Liquidnet Holdings, Inc.
Joseph.Boyer(a)liquidnet.com
T   +1 646.660.8352
C   +1 646.284.8394


-----Original Message-----
From: cobbler-bounces(a)lists.fedorahosted.org
[mailto:[e-mail]] On Behalf Of Jasper Capel
Sent: Tuesday, October 14, 2008 4:50 PM
To: cobbler mailing list
Subject: Re: Static networking -- nameserver configuration and hostnames

Joseph Boyer Jr. wrote:
>  Jasper,
>
>  I would tend to think that the intent of having a host name parameter part of the NIC
> configuration is to address the needs of multi-homed machines. At least that is what I use
> them for.  In my environment most systems have a public and private interface and I use
> the hostname associated with each NIC configuration to properly set up /etc/hosts via
> configuration RPM. I use the system name as the "Node name", that is the name
> you see when you log into the box or grep HOSTNAME /etc/sysconfig/network.
>  
I'm currently doing this as well, but I think we should aim at
configuring the system's hostname from cobbler (and we easily could,
with the post_install_network_config snippet). Maybe designating one
interface as primary and using the hostname from this interface would be
a nicer alternative than letting anaconda just "pick one"?

Jasper
_______________________________________________
cobbler mailing list
cobbler(a)lists.fedorahosted.org
https://fedorahosted.org/mailman/listinfo/cobbler

[Jasper Capel]

Joseph Boyer Jr. wrote:
>  Ok. I see your issue.
>   
The thing is, it wasn't really an issue until I added the possibility of 
giving your network interface any name you like.

Previously we had intf0, intf1, ..., intfN, and you could just configure 
your networking information in the order of your physical devices. The 
booting interface is sorted by the IPAPPEND option in syslinux and there 
you go.
Now we can have an interface foo, bar, mgmt, internet, mylan0, mylan0, 
but these are now processed alphabetically (right?). So this would only 
work correctly if my system's first interface is actually connected to 
network "bar", hence the need to match a mac-address to a physical 
interface in the %pre-section of the kickstart and use that information 
to configure networking in anaconda. Of course we'd only want to do this 
if the interfaces aren't called ethX in Cobbler.

Jasper

[Michael DeHaan]

Jasper Capel wrote:
>  Joseph Boyer Jr. wrote:
>    
> > Ok. I see your issue.
> >
> >     
>  The thing is, it wasn't really an issue until I added the possibility of 
>  giving your network interface any name you like.
>
>  Previously we had intf0, intf1, ..., intfN, and you could just configure 
>  your networking information in the order of your physical devices. The 
>  booting interface is sorted by the IPAPPEND option in syslinux and there 
>  you go.
>  Now we can have an interface foo, bar, mgmt, internet, mylan0, mylan0, 
>  but these are now processed alphabetically (right?). So this would only 
>  work correctly if my system's first interface is actually connected to 
>  network "bar", hence the need to match a mac-address to a physical 
>  interface in the %pre-section of the kickstart and use that information 
>  to configure networking in anaconda. Of course we'd only want to do this 
>  if the interfaces aren't called ethX in Cobbler.
>
>  Jasper
>  _______________________________________________
>  cobbler mailing list
>  cobbler(a)lists.fedorahosted.org
>  https://fedorahosted.org/mailman/listinfo/cobbler
>     
Additionally in a future commit/upgrade, any interfaces named "intfN" 
will be automatically renamed "ethN" to comply.

This will not affect existing configurations, but it might affect 
someone's XMLRPC code in minor ways if they were hardcoding things.

Anything not starting with "intf<integer>" will be legal, so you can 
name interfaces "mgmt".

--Michael

[Michael DeHaan]

Joseph Boyer Jr. wrote:
>  Ok. I see your issue.
>
>  The way I have been getting around this is to add a kickstart option: ksdevice="mac
> address of install nic" and or by specifying the kernel parameter: pci=nobfort, which
> will disable the old 2.4 NIC enumeration algorithm which is used in 2.6.9-55 or newer
> kernels and use the 2.6 nic enumeration algorithm.
>
>  Check redhat knowledge base faq: http://kbase.redhat.com/faq/FAQ_46_10460.shtm for more
> info.
>
>  Dell has also produce a white paper on the NIC enumeration issue:
> http://linux.dell.com/files/whitepapers/nic-enum-whitepaper-v3.pdf
>
>  --joe
>
>  Joseph Boyer Jr
>  Enterprise Technology Services
>  Liquidnet Holdings, Inc.
>  Joseph.Boyer(a)liquidnet.com
>  T   +1 646.660.8352
>  C   +1 646.284.8394
>
>     
I think jasper's saying if we're going to be nice and auto-filling in 
the /etc/sysconfig/network-bits from cobbler, it would be nice to have 
the hostname filled in as well.

This probably applies regardless of whether we do the 
post_install_network_config. The seems to be just what name_eths does in 
the whitepaper.

But you're right, ksdevice=MAC is cleaner, but the one thing that 
doesn't get you is to ensure that eth2 in cobbler is eth2 in 
/etc/sysconfig/network*

However, the logic to implement this versus ksdevice=bootif is messy, so 
if we just do what we're doing (and add the post_install_network_config) 
snippet I think it works out nicely.

The trick is just to figure out which hostname to use.

(We could also look into having an additional option of 
--boot-interface=name which would add that argument and then auto-select 
that choice for the hostname, but that's complicated, so that should 
probably be addressed later)

Main thing is to come up with something that both makes folks lives 
easier and also does not break anyone who is not expecting it. A careful 
line to tread, though I do like the idea of the post_install_network 
snippet as it also allows for bonding and VLAN config, which Anaconda 
also does not know about. If it also solves ordering at the same time, 
that seems to be goodness.

Just my thoughts though, definitely not final. Sound good? Yes? No?

--Michael



>  -----Original Message-----
>  From: cobbler-bounces(a)lists.fedorahosted.org
> [mailto:[e-mail]] On Behalf Of Jasper Capel
>  Sent: Tuesday, October 14, 2008 4:50 PM
>  To: cobbler mailing list
>  Subject: Re: Static networking -- nameserver configuration and hostnames
>
>  Joseph Boyer Jr. wrote:
>    
> > Jasper,
> >
> > I would tend to think that the intent of having a host name parameter part of the NIC
> configuration is to address the needs of multi-homed machines. At least that is what I use
> them for.  In my environment most systems have a public and private interface and I use
> the hostname associated with each NIC configuration to properly set up /etc/hosts via
> configuration RPM. I use the system name as the "Node name", that is the name
> you see when you log into the box or grep HOSTNAME /etc/sysconfig/network.
> >
> >     
>  I'm currently doing this as well, but I think we should aim at
>  configuring the system's hostname from cobbler (and we easily could,
>  with the post_install_network_config snippet). Maybe designating one
>  interface as primary and using the hostname from this interface would be
>  a nicer alternative than letting anaconda just "pick one"?
>
>  Jasper
>  _______________________________________________
>  cobbler mailing list
>  cobbler(a)lists.fedorahosted.org
>  https://fedorahosted.org/mailman/listinfo/cobbler
>
>
>  _______________________________________________
>  cobbler mailing list
>  cobbler(a)lists.fedorahosted.org
>  https://fedorahosted.org/mailman/listinfo/cobbler
>

[Michael DeHaan]

Joseph Boyer Jr. wrote:
>  Jasper,
>
>  I would tend to think that the intent of having a host name parameter part of the NIC
> configuration is to address the needs of multi-homed machines. At least that is what I use
> them for.  In my environment most systems have a public and private interface and I use
> the hostname associated with each NIC configuration to properly set up /etc/hosts via
> configuration RPM. I use the system name as the "Node name", that is the name
> you see when you log into the box or grep HOSTNAME /etc/sysconfig/network.
>
>     
Correct.

Currently we can serve up a different name via DNS (when cobbler 
manage_dns is turned on) to each interface in a dual homed system, 
because it has different IP's.

--Michael



>  Joseph Boyer Jr
>  Enterprise Technology Services
>  Liquidnet Holdings, Inc.
>  Joseph.Boyer(a)liquidnet.com
>  T   +1 646.660.8352
>  C   +1 646.284.8394
>
>
>  -----Original Message-----
>  From: cobbler-bounces(a)lists.fedorahosted.org
> [mailto:[e-mail]] On Behalf Of Jasper Capel
>  Sent: Tuesday, October 14, 2008 4:28 PM
>  To: cobbler mailing list
>  Subject: Static networking -- nameserver configuration and hostnames
>
>  Hey all,
>
>  Currently, it looks like you can't provide an installed system with a
>  working resolv.conf, if you're not using DHCP (of course you can snippet
>  it).
>  How about a
>  cobbler system edit --name=foo.example.com --name-servers="192.168.0.1
>  192.168.0.2"?
>
>  I also noticed the system's hostname is a property of a network
>  interface. Is this intended, or should we make the hostname a property
>  of the system? I think this is kind of confusing; although anaconda
>  enables you to provide a hostname on each network-line, a system should
>  only have one.
>
>  Jasper
>  _______________________________________________
>  cobbler mailing list
>  cobbler(a)lists.fedorahosted.org
>  https://fedorahosted.org/mailman/listinfo/cobbler
>
>
>  _______________________________________________
>  cobbler mailing list
>  cobbler(a)lists.fedorahosted.org
>  https://fedorahosted.org/mailman/listinfo/cobbler
>