Networking nightmare

SUSE Linux Enterprise Server SLES Networking
1

I am new to SLES, but I am very sure that I like it. I am mostly a GUI/Webmin sort, and for that reason, I especially like this setup.

However, I have an issue with 2 things:

  1. My setup is a 40Mbps in / 5Mbps out connection with Static IP and DNS, an Ethernet router, a dedicated machine that has been serving up my sites for 5 years and has been moved twice and has never let me down, ever. But, it is time to replace Fedora 9. I am trying to get this new machine setup so I can replace the old one, and I guess things have changed considerably since I started this time in '08!

I’ve tried the new Fedora, Debian, Knoppix, openSUSE, even FreeBSD (too CLI ignorant to even bother). CentOS was working fine until I did some upgrades, and my network connection vanished. I cannot get it working with SUSE either.

I don’t want NetworkManager (cannot yet find how to uninstall it either), rather the traditional ifup network setup, which I’ve tried, still with no success. My eth0 keeps being rewritten to a netmask of /24 is about all I can find.

I need some pointers to what surely is a very simple resolution if there are any to be had. There arte no Linux folks available to me here in this town. It’s not that the documentation does not hold my answers, rather that I’m dyslexic, and it usually fails me everytime.

My install is on an Intel x86_64 machine from a single clean partition.

2

tarzy wrote:
[color=blue]

I need some pointers to what surely is a very simple resolution if
there are any to be had. There arte no Linux folks available to me
here in this town. It’s not that the documentation does not hold my
answers, rather that I’m dyslexic, and it usually fails me everytime.

My install is on an Intel x86_64 machine from a single clean
partition.[/color]

You may be new to SLES but it sounds like you do have Linux experience.
You know then there are always minor differences in the way things are
configured from one distribution to the next. The best way to learn
about those differences is by reading the documentation although, in
your case, I can see where that can be problematic. :frowning:

You do not say much about your hardware or what you have configured. My
first guess would be that you have either a driver or a configuration
issue.

I would begin with YaST Networking. Here you can specify whether you
want to use ifup or NetworkManager. The rest is pretty straight forward
if you understand network basics.

If that pointer doesn’t resolve your issue for you, we’ll need more
information. Please post output from the following commands:

cat /etc/*release
ifconfig -a
netstat -rn

–
Kevin Boyle - Knowledge Partner
If you find this post helpful and are logged into the web interface,
show your appreciation and click on the star below…

3

[QUOTE=KBOYLE;15779]tarzy wrote:
[color=blue]

I need some pointers to what surely is a very simple resolution if
there are any to be had. There arte no Linux folks available to me
here in this town. It’s not that the documentation does not hold my
answers, rather that I’m dyslexic, and it usually fails me everytime.

My install is on an Intel x86_64 machine from a single clean
partition.[/color]

You may be new to SLES but it sounds like you do have Linux experience.
You know then there are always minor differences in the way things are
configured from one distribution to the next. The best way to learn
about those differences is by reading the documentation although, in
your case, I can see where that can be problematic. :frowning:

You do not say much about your hardware or what you have configured. My
first guess would be that you have either a driver or a configuration
issue.

I would begin with YaST Networking. Here you can specify whether you
want to use ifup or NetworkManager. The rest is pretty straight forward
if you understand network basics.

If that pointer doesn’t resolve your issue for you, we’ll need more
information. Please post output from the following commands:

cat /etc/*release
ifconfig -a
netstat -rn

–
Kevin Boyle - Knowledge Partner
If you find this post helpful and are logged into the web interface,
show your appreciation and click on the star below…[/QUOTE]

Thanks very much for the assistance! You may have something with the “driver” issue, not sure yet. Here is the output from the 3 networking commands you so kindly gave:

localhost:~ # ifconfig -a

eth0 Link encap:Ethernet HWaddr C8:9C:DC:B1:A0:F6

inet addr:192.168.1.26 Bcast:192.168.1.255 Mask:255.255.255.0

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)

Interrupt:44 Base address:0xc000

lo Link encap:Local Loopback

inet addr:127.0.0.1 Mask:255.0.0.0

UP LOOPBACK RUNNING MTU:16436 Metric:1

RX packets:45 errors:0 dropped:0 overruns:0 frame:0

TX packets:45 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:0

RX bytes:2618 (2.5 Kb) TX bytes:2618 (2.5 Kb)

localhost:~ # cat /etc/*release

LSB_VERSION=“core-2.0-noarch:core-3.2-noarch:core-4.0-noarch:core-2.0-x86_64:core-3.2-x86_64:core-4.0-x86_64”

SUSE Linux Enterprise Server 11 (x86_64)

VERSION = 11

PATCHLEVEL = 2

localhost:~ # netstat -rn
Kernel IP routing table

Destination Gateway Genmask Flags MSS Window irtt Iface

0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0

127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo

169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0

192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0

I’m going to get a cheat sheet of Linux networking commands, which will likely aid me a fair amount.

I have survived on guesswork, hunches, and still at 67, a pretty good memory. The Dyslexia is due to my particular personality defects and extreme preoccupation.

The machine is a small form factor Intel Core2 duo, has an integrated NIC: so called “Gigabit”, 3GB DDR3 RAM, a 1TB HDD, and seems to run well with this new OS, which I really like; but I’ll need to get it on the web reasonably soon, and must test it on my LAN first.

I am not good at any of this, but I do remember most of what I learn, and know to read the files before messing with anything serious, such as when it instructs you as to what populates it; something I just learned in the last few days.

Hoping it won’t do any harm, and definitely not spamming this forum, here is what I do: playguitarvideosdotcom & craigtarwaterdotcomslashguitar.

I’l look deeper into Linux networking, some new cheat sheets and report back when I solve this issue. I do see a couple of things in the output that I’m curious as to whether they’re correct.

Regards, tarzy

4

Hi tarzy,

eth0 Link encap:Ethernet HWaddr C8:9C:DC:B1:A0:F6 inet addr:192.168.1.26 Bcast:192.168.1.255 Mask:255.255.255.0 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
your server’s link sees a bit under-utilized…

My eth0 keeps being rewritten to a netmask of /24 is about all I can find.

while I assume you’re setting up your machine via YaST (where you will find the according settings in “Network devices” - “Network settings” - select your device if not already done - “Edit” - “statically assign IP address” - fill in your values), there’s a chance that you’re getting your machine’s IP address assigned via DHCP.

You mentioned a router, is it configured to hand out addresses via DHCP? The question then remains - if the router’s DHCP server hands out a network mask of /24, why’d you want to change that?

Regards,
Jens

5

[QUOTE=jmozdzen;15788]Hi tarzy,

eth0 Link encap:Ethernet HWaddr C8:9C:DC:B1:A0:F6 inet addr:192.168.1.26 Bcast:192.168.1.255 Mask:255.255.255.0 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
your server’s link sees a bit under-utilized…

My eth0 keeps being rewritten to a netmask of /24 is about all I can find.

while I assume you’re setting up your machine via YaST (where you will find the according settings in “Network devices” - “Network settings” - select your device if not already done - “Edit” - “statically assign IP address” - fill in your values), there’s a chance that you’re getting your machine’s IP address assigned via DHCP.

You mentioned a router, is it configured to hand out addresses via DHCP? The question then remains - if the router’s DHCP server hands out a network mask of /24, why’d you want to change that?

Regards,
Jens[/QUOTE]

By now, it is apparent that my networking skills are way below par; my only ability is to analyze other setups/situations, and then try various fixes to see what resolves the impasse.

My Netgear Router is configured for DHCP as I have a ROKU for some TV, and the iPhone while here to keep Cell data usage down. I’ve tried the YaST which is the default GUI app that initiates when I don’t directly look at/change any of the files. My main HTTP machine, the one I’m replacing, may hold the answers, after I analyze it further using the new excellent info I’ve found for making checks via the console. I’m of course reasonably confused by such things as the Ethernet Loopback interface vs. the Ethernet interface. As you have mentioned, I do have this machine set with a static IP, which shows in both the eth-lo and eth0 info returns.

Thanks to all of you for your kind responses.

6

[QUOTE=tarzy;15782]Thanks very much for the assistance! You may have something with the “driver” issue, not sure yet. Here is the output from the 3 networking commands you so kindly gave:

localhost:~ # ifconfig -a

eth0 Link encap:Ethernet HWaddr C8:9C:DC:B1:A0:F6

inet addr:192.168.1.26 Bcast:192.168.1.255 Mask:255.255.255.0

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)

Interrupt:44 Base address:0xc000

lo Link encap:Local Loopback

inet addr:127.0.0.1 Mask:255.0.0.0

UP LOOPBACK RUNNING MTU:16436 Metric:1

RX packets:45 errors:0 dropped:0 overruns:0 frame:0

TX packets:45 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:0

RX bytes:2618 (2.5 Kb) TX bytes:2618 (2.5 Kb)

localhost:~ # cat /etc/*release

LSB_VERSION=“core-2.0-noarch:core-3.2-noarch:core-4.0-noarch:core-2.0-x86_64:core-3.2-x86_64:core-4.0-x86_64”

SUSE Linux Enterprise Server 11 (x86_64)

VERSION = 11

PATCHLEVEL = 2

localhost:~ # netstat -rn
Kernel IP routing table

Destination Gateway Genmask Flags MSS Window irtt Iface

0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0

127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo

169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0

192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0

I’m going to get a cheat sheet of Linux networking commands, which will likely aid me a fair amount.

I have survived on guesswork, hunches, and still at 67, a pretty good memory. The Dyslexia is due to my particular personality defects and extreme preoccupation.

The machine is a small form factor Intel Core2 duo, has an integrated NIC: so called “Gigabit”, 3GB DDR3 RAM, a 1TB HDD, and seems to run well with this new OS, which I really like; but I’ll need to get it on the web reasonably soon, and must test it on my LAN first.

I am not good at any of this, but I do remember most of what I learn, and know to read the files before messing with anything serious, such as when it instructs you as to what populates it; something I just learned in the last few days.

Hoping it won’t do any harm, and definitely not spamming this forum, here is what I do: playguitarvideosdotcom & craigtarwaterdotcomslashguitar.

I’l look deeper into Linux networking, some new cheat sheets and report back when I solve this issue. I do see a couple of things in the output that I’m curious as to whether they’re correct.

Regards, tarzy[/QUOTE]

here is the output from my WWW server checking all interfaces:

ifconfig -a
eth0 Link encap:Ethernet HWaddr 00:13:D3:06:0B:53
inet addr:192.168.1.25 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::213:d3ff:fe06:b53/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:106866 errors:0 dropped:0 overruns:0 frame:0
TX packets:63595 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:71471869 (68.1 MiB) TX bytes:21757280 (20.7 MiB)
Interrupt:23 Base address:0x4000

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:15525 errors:0 dropped:0 overruns:0 frame:0
TX packets:15525 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:837570 (817.9 KiB) TX bytes:837570 (817.9 KiB)

pan0 Link encap:Ethernet HWaddr D6:BD:9E:43:C5:19
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:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

sit0 Link encap:IPv6-in-IPv4
NOARP MTU:1480 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:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

Being as this is Fedora and not SUSE, I’ll have to be careful, but it seems to me initially that this is what I should be seeing once I get the new machine figured out. Talk about “Brain squirming”!!

7

tarzy wrote:
[color=blue]

I’m going to get a cheat sheet of Linux networking commands, which
will likely aid me a fair amount.[/color]

Yes, I’m sure it will. When I started working with Linux about five
years ago my biggest issue was learning how to obtain the information I
needed to manage the system
[color=blue]

and still at 67, a pretty good memory.[/color]

That reminds me of someone else I know!

[color=blue]

The machine is a small form factor Intel Core2 duo, has an integrated
NIC: so called “Gigabit”, 3GB DDR3 RAM, a 1TB HDD, and seems to run
well with this new OS, which I really like; but I’ll need to get it
on the web reasonably soon, and must test it on my LAN first.[/color]

If there are any issues with that machine, you should see something in
the log. Actually, you’ll see a lot of things in the log but maybe
something will stand out. The log files are stored in /var/log. The
main one, and the one you should check first, is /var/log/messages.

[color=blue]

I’l look deeper into Linux networking, some new cheat sheets and
report back when I solve this issue. I do see a couple of things in
the output that I’m curious as to whether they’re correct.[/color]

From the information you provided:

You’re running SLES11-SP2. SLES11-SP3 has recently been released. If
this is a new installation, you should probably go with the current
release although SLES11-SP2 should work just fine.

To check where your network configuration may be failing, “ping” your
network interface, then your gateway, then a host on the Internet using
its IP address, then again using its domain name.

ping 192.168.1.26
ping 192.168.1.1
ping 130.57.66.10
ping forums.suse.com

If the last one fails, you probably haven’t specified a DNS server. You
can do that from YaST Network Settings.

I just read your reply to Jens (jmozden)…

When you are setting up a server, it’s best to use a static IP address.
Make sure you haven’t assigned an address that is currently used by
another device. Don’t worry about the lo interface. It’s fine.

–
Kevin Boyle - Knowledge Partner
If you find this post helpful and are logged into the web interface,
show your appreciation and click on the star below…

8

Hi tarzy,

we can help you with that :wink:

ok, so that part sounds already set up properly. You’re talking about a “web server”, so I assume you want to pass connections from the Internet to that server. In that case, you either ought to configure a static IP address at the web server, or configure a static mapping (Ethernet/MAC address of server to IP address handed out by dhcp server), so that the web server will always have the same IP address all the time… else you’d have to update the port forwarding in your router whenever the IP of the web server changes.

I’ve seen the other message where you show the IP configuration of your old server, which is quite similar to the new one’s - except for the distinct IP address.

What you’ll have to add to your configuration when setting things up manually is

  • the default route, pointing to the IP address of your router’s LAN interface (you already have that, see “netstat” output you gave)
  • DNS resolver info, pointing again to the same router address (see the content of /etc/resolv.conf on your old server)

There’s no such thing as an Ethernet Loopback interface :wink: - it’s just “loopback interface” and it simply does what the name implies: Any packet sent “out” via that interface is immediately returned back to that interface. It’s used by the server to talk to itself, so to say… when the machine has no working Ethernet interface (or other), the lo interface will always be there and work… so some internal communication will preferably talk to “127.0.0.1” than to “192.168.1.25”.

BTW, on your old server, there were interfaces for “personal area networking” (pan0, sit0), most probably to provide network access for Bluetooth devices. If you don’t actually need that, just leave 'em out: That stuff can get complicated rather quickly.

The subnet mask goes along with the IP address, so it seems you have that configured statically as well… what else would you have it expected to be (regarding your initial question about it changing to 255.255.255.0, also known as “/24”)?

I’d say, you’re basically on a good track - what exactly is missing or not working, from your current point of view? If it’s that you cannot reach the server from the Internet - then you should check the port forwarding settings of your router, which might still forward to the IP address 192.168.1.25 instead of .26. Or reconfigure your old server to another IP address and have the new one take over the .25.

With regards,
Jens

9

[QUOTE=KBOYLE;15817]tarzy wrote:
[color=blue]

I’m going to get a cheat sheet of Linux networking commands, which
will likely aid me a fair amount.[/color]

Yes, I’m sure it will. When I started working with Linux about five
years ago my biggest issue was learning how to obtain the information I
needed to manage the system
[color=blue]

and still at 67, a pretty good memory.[/color]

That reminds me of someone else I know!

[color=blue]

The machine is a small form factor Intel Core2 duo, has an integrated
NIC: so called “Gigabit”, 3GB DDR3 RAM, a 1TB HDD, and seems to run
well with this new OS, which I really like; but I’ll need to get it
on the web reasonably soon, and must test it on my LAN first.[/color]

If there are any issues with that machine, you should see something in
the log. Actually, you’ll see a lot of things in the log but maybe
something will stand out. The log files are stored in /var/log. The
main one, and the one you should check first, is /var/log/messages.

[color=blue]

I’l look deeper into Linux networking, some new cheat sheets and
report back when I solve this issue. I do see a couple of things in
the output that I’m curious as to whether they’re correct.[/color]

From the information you provided:

You’re running SLES11-SP2. SLES11-SP3 has recently been released. If
this is a new installation, you should probably go with the current
release although SLES11-SP2 should work just fine.

To check where your network configuration may be failing, “ping” your
network interface, then your gateway, then a host on the Internet using
its IP address, then again using its domain name.

ping 192.168.1.26
ping 192.168.1.1
ping 130.57.66.10
ping forums.suse.com

If the last one fails, you probably haven’t specified a DNS server. You
can do that from YaST Network Settings.

I just read your reply to Jens (jmozden)…

When you are setting up a server, it’s best to use a static IP address.
Make sure you haven’t assigned an address that is currently used by
another device. Don’t worry about the lo interface. It’s fine.

–
Kevin Boyle - Knowledge Partner
If you find this post helpful and are logged into the web interface,
show your appreciation and click on the star below…[/QUOTE]

Thanks more than I can say!

Pings result in gateway OK, Forums OK, Interface: “destination host unreachable”.

I must go do some volunteer work (100 year-old home) and will check the logs to have something to muse on while I’m removing 30-40 sq. feet of 100 year-old paint with a heat gun in the Sun at 80 degrees and climbing.

Before I go, I need to say I switched from ifup to Network mgr, but keeping things static. I notice it is greyed out on chk box for assign hostname with dhcp; I did that, but don’t know where it was, and can’t undo it yet, but I will. Lastly, all of my testing in the past was on my LAN, including this Fedora box I’m writing from. It has port 80 until the new rig passes the testing phase. Back in my beginnings I set up an Ubuntu machine with 2 virtual hosts and tested it fine, but wound up not using it as it was an inferior donated machine 32 bits as well.

I’ll keep experimenting after I examine the logs later. Sooner or later it’s bound to start working.

Regards to all, tarzy…

10

tarzy wrote:
[color=blue]

Pings result in gateway OK, Forums OK, Interface: “destination host
unreachable”.[/color]

The fact that you can ping your gateway and hosts on the Internet shows
that your networking is working. Your SLES server can be configured so
that it doesn’t respond to “echo requests” (ping) so I wouldn’t worry
too much about the local interface at this time.

I would go back to YaST Network Settings and make sure you are using
ifup then test again to make sure everything is still working.

At this point, what issues are you still experiencing?

–
Kevin Boyle - Knowledge Partner
If you find this post helpful and are logged into the web interface,
show your appreciation and click on the star below…

11

[QUOTE=KBOYLE;16172]tarzy wrote:
[color=blue]

Pings result in gateway OK, Forums OK, Interface: “destination host
unreachable”.[/color]

The fact that you can ping your gateway and hosts on the Internet shows
that your networking is working. Your SLES server can be configured so
that it doesn’t respond to “echo requests” (ping) so I wouldn’t worry
too much about the local interface at this time.

I would go back to YaST Network Settings and make sure you are using
ifup then test again to make sure everything is still working.

At this point, what issues are you still experiencing?

–
Kevin Boyle - Knowledge Partner
If you find this post helpful and are logged into the web interface,
show your appreciation and click on the star below…[/QUOTE]

SOLVED!!

Maybe it helped to go scrape paint for a while; anyway, I just opened the “Network wired”, and unchecked the box “assign hostname to loopback IP” (although I don’t think that was it), then found even though I put it there earlier, I thought, there was nothing in the default gateway. After entering and proceeding, I could tell I was in for something good as YaST mgr. took it’s time going through the configs, and vioal! Opened the Browser, and the default homepage is suse.com. Good to go, finally.

I have 3 other questions, but I maybe should ask them in the proper spots in the forum. I’m not much betteer in forums than I am in networking!

An ethics question as to use of the software ________________

an annoyance pertaining to the keyboard ____________________

and how to install an already downloaded updated browser on the old machine _________________________

which I’m writing from. If someone would tell me the spots by each underscores, I’d appreciate it.

Again, thanks to all who gave me their valuable time!

tarzy

12

These are the SUSE Forums. Most are product specific support forums, as the name implies.

For your questions, this is where I would post:

Forum: Chatting over the Back Fence

Forum: SLES Hardware
or
Forum: SLED Hardware

Forum: SLES Updates

I’m glad we were able to help and hope to see your continued participation.