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› › [Solved] Centos 6.8 32 bit KVM on online.net strange network problem
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[Solved] Centos 6.8 32 bit KVM on online.net strange network problem

akhfaakhfa Member
edited September 2016 in Help

Solution

you can follow this tutorial until the end of the page
https://documentation.online.net/en/dedicated-server/operating-system/distribution-virtualisation/distribution-proxmox/distribution-proxmox-ve-4

Problem

Do you all ever install centos 6.8 32bit KVM on proxmox 4?

I try to install, but the default gateway cannot be added in the routing table.

I tried to install centos 7 or centos 6 CT and the network works fine.

Everything I try, ifup, service network restart, the result is same. I was trying centos 6.8 netinstall, it also cannot connect to the network.

I find thet prefix 32 is a problem in centos 6 here

https://www.centos.org/forums/viewtopic.php?t=8494

I don't know if it is true or not.

I don't have any idea where is the problem. I also contacted technical assistance, but I think this is not hardware problem.

Update 1

Trying to install 64bit centos 6.8 with same configuration, the default gateway routing table still not appear.

route -n show that there is only one routing rule, it is

destination: 169.254.0.0
gateway: 0.0.0.0
genmask: 255.255.0.0

I think this is default config if centos cannot detect network gateway.

Update 2

Trying Ubuntu server 16.04.1 32 bit, cannot continue installation when I must fill gateway IP. It said like "network is unreachable"

Trying centos 6.8 32 bit liveCD and try to add static routing like centos 7 installation
I can set static route like this

123.123.123.1   0.0.0.0         255.255.255.255 UH    100    0        0 ens18
456.234.123.456 0.0.0.0         255.255.255.255 UH    100    0        0 ens18

where 123.123.123.1 is online.net gateway and 456.234.123.456 is server IP. But fail when I try to add default gateway

ip route add default via 123.123.123.1
or
ip route add 0.0.0.0/0.0.0.0 via 123.123.123.1 dev eth0

it show error

RTNETLINK answers: Network is unreachable

Update 3

Trying to install ubuntu server without network and set static network after installed -> success

Trying it on centos 6, fail :(

I get up about this. One night searching the solution and I get nothing :(

Can someone explain what's happen behind this case? Why does centos 7 is working fine, but ubuntu server and centos 6 doesn't?

Comments

  • myhkenmyhken Member

    Don't understand why online.net don't offer CentOS 6.8 but only CentOS 7

  • iBotiBot Member

    It's due to Serial Console even though you can fix it by adding the parameters in GRUB. Also, I've tried swapping between XC and SC, all AMS servers are borked. Sub par Disk speeds, I regret upgrading from kidechire.

  • akhfaakhfa Member

    @iBot said:
    It's due to Serial Console even though you can fix it by adding the parameters in GRUB. Also, I've tried swapping between XC and SC, all AMS servers are borked. Sub par Disk speeds, I regret upgrading from

    kidechire

    So there is real problem with centos 6 in online.net, isn't?

    Or do you ever get same problem in ovh or maybe hetzner?

  • iBotiBot Member

    It's fine with OVH but it's online's personal range that has pissed me off.

  • akhfaakhfa Member

    @iBot said:
    It's fine with OVH but it's online's personal range that has pissed me off.

    Can you tell me how ovh personal range look like? I never order OVH dedicated before.

  • FalzoFalzo Member

    akhfa said: Do you all ever install centos 6.8 32bit KVM on proxmox 4?

    just to get this right, you are not about installing centos 6.8 on your dedicated at online.net directly but installing it as a guest via proxmox 4 which is already running on your online.net server?

    and your talking about KVM in the title but CT in the posting itself whereas the latter means using LXC in proxmox - KVM boxes are named VMs.

    to help you out please clarify, and yes you may run into the same trouble on ovh or hetzner because it so far sounds like a problem with the bridge/routing setup on proxmox, not the setup of IPs at online.net.

  • akhfaakhfa Member
    edited September 2016

    @Falzo said:

    akhfa said: Do you all ever install centos 6.8 32bit KVM on proxmox 4?

    just to get this right, you are not about installing centos 6.8 on your dedicated at online.net directly but installing it as a guest via proxmox 4 which is already running on your online.net server?

    Yes, my main goal is install Centos 6.8 32 bit KVM as a guest via Proxmox VE4

    and your talking about KVM in the title but CT in the posting itself whereas the latter means using LXC in proxmox - KVM boxes are named VMs.

    I try to install KVM, but failed.

    And then I try to install LXC in case the problem is network problem.

    I found out that Centos 6 64 bit LXC is working fine, also with Ubuntu server 16.04.1 KVM and centos 7 KVM.

    So I assume that the problem is not network, but something that Centos 6 on KVM cannot find the next network hop even the network configuration is same as another OS.

    I don't know what the real problem is.

    to help you out please clarify, and yes you may run into the same trouble on ovh or hetzner because it so far sounds like a problem with the bridge/routing setup on proxmox, not the setup of IPs at online.net.

    If the problem is bridge/routing on proxmox, why do centos 7 and ubuntu can connect to the network?

  • iBotiBot Member
    edited September 2016

    @akhfa said:

    @iBot said:
    It's fine with OVH but it's online's personal range that has pissed me off.

    Can you tell me how ovh personal range look like? I never order OVH dedicated before.

    I planned to upgrade from kidechire to SC SATA 2016.

    First Server Delivered at AMS. Installed twice, found disk io sitting at 11MB/s. Filed a ticket, was replaced with a server in France. This server rebooted whenever there was a load, and I am talking sysbench for 30mins.

    This process kept on until I received my 5th server at AMS. Still the same issue and I now I finally gave up (even requested an upgrade to classic and was denied)

    Imho: Just stay away. Terrible experience, lost a great hardware during the upgrade.

  • FalzoFalzo Member
    edited September 2016

    akhfa said: Yes, my main goal is install Centos 6.8 32 bit KVM as a guest via Proxmox VE4

    then this is clearly not a problem with online.net

    akhfa said: If the problem is bridge/routing on proxmox, why do centos 7 and ubuntu can connect to the network?

    because networking is implemented differently whether you are using LXC or KVM. and it also depends if you are trying a routed setup, a bridged setup, if you have a single additional IP or a whole subnet and so on.

    as said above, I'd bet you run into similar issues with other providers as this is clearly an issue with how to setup proxmox properly.

    to help you more details are needed:

    • do you use a single additional IP for that KVM guest, or one of a whole subnet?
    • does this IP belong to the same subnet as the main IP?
    • if it is a single IP, have you requested/set up a virtual mac for this IP?
    • have you already set up a bridge device within proxmox or manually?
    • how does the /etc/network/interfaces on your host node look like?

    there are some different ways to get it working, but most probably with IPs from different subnets it won't work out of the box with KVM, just opposite as LXC mostly does.

    you could try to setup your centos from iso as a minimal version and configure the network afterwards via VNC , most netinst isos aren't able to detect the correct network setting while setup process in such a configuration.

    again: this is most probably not an issue with online.net ...

    have a look at hetzners wiki regarding networking in proxmox to get some further hints: https://wiki.hetzner.de/index.php/Proxmox_VE/en

    Thanked by 1akhfa
  • akhfaakhfa Member

    @Falzo said:

    akhfa said: Yes, my main goal is install Centos 6.8 32 bit KVM as a guest via Proxmox VE4

    then this is clearly not a problem with online.net

    I think so, but I don't know what's wrong

    • do you use a single additional IP for that KVM guest, or one of a whole subnet?

    I order one IP, and assign one virtual mac address

    • does this IP belong to the same subnet as the main IP?

    It is differrent subnet

    • if it is a single IP, have you requested/set up a virtual mac for this IP?

    Yes I have. I successfully setup the network of another OS with this.

    • have you already set up a bridge device within proxmox or manually?

    I use online.net template. The template is configured with bridged network.

    • how does the /etc/network/interfaces on your host node look like?

    this is interfaces file (just slightly different with hetzner)

    auto lo
iface lo inet loopback

iface eth0 inet manual

iface eth1 inet manual

auto vmbr0
iface vmbr0 inet static
    address 163.xxx.xx.xxx
    netmask 255.255.255.0
    gateway 163.xxx.xx.1
    bridge_ports eth0
    bridge_stp off
    bridge_fd 0

    And I get IP 212.xxx.xxx.xxx for the guest.

    You can find online.net tutorial here

    https://documentation.online.net/en/dedicated-server/operating-system/distribution-virtualisation/distribution-proxmox/distribution-proxmox-ve-4

    I have 2 server proxmox with online.net and all the guest (mainly centos 7 with some ubuntu) is fine except this centos 6. And then 1 proxmox with wholesaleinternet is also fine with online.net network configuration example.

    you could try to setup your centos from iso as a minimal version and configure the network afterwards via VNC , most netinst isos aren't able to detect the correct network setting while setup process in such a configuration.

    I did this. Success with Ubuntu server, fail with centos 6 :(

  • akhfaakhfa Member

    @iBot said:
    Imho: Just stay away. Terrible experience, lost a great hardware during the upgrade.

    Maybe you are out of luck when order that server. I order SC, XC, LT, MD, they are working fine :)

    but yeah the problem is just the high setup fee

  • FalzoFalzo Member

    @akhfa said:

    thanks for the details, that may help a lot to narrow down the problem.

    good to hear you have a vmac already assigned, as thats neccessary for bridged setup, and as expected the IP is from different setup, that may cause autodetection of network config during install to fail...

    so the other centos 7 or ubuntu installations you are running are KVM as well and working as expected?

    then I have to agree that the issue has to be somewhere within the centos 6 network config itself.

    From what template/ISO are you installing?

    I have to admit I am much more into debian/ubuntu than centos, but that very last part on the online.net page seems to cover the settings, mind sharing how your config files of that guest looked like (if possible)?

    are you told of another gateway for that additional IP or is there none given? (I never used additional IPs with online.net so far)

    I do prefer the hetzner-like setup with pointopoint and /32 subnet mask on the hostnode as wall as I did run into less trouble with that ;-)

    and you could always try to switch to a routed setup, which should work, even if you don't have a virtual mac assigned to your additional IP.

    Thanked by 1akhfa
  • akhfaakhfa Member

    My Final Reply

    FINALLY, I can make my Centos 6 Works :D

    Thanks a lot @Falzo for your sharing

    I don't see centos configuration on online.net proxmox tutorial. One long night searching and the solution is on the end page of what tutorial I follow. Aaahhh this is funny :D

    For the others that have same problem, you can follow this tutorial until the end of the page

    https://documentation.online.net/en/dedicated-server/operating-system/distribution-virtualisation/distribution-proxmox/distribution-proxmox-ve-4

    This is what I want to reply first

    @Falzo said:

    so the other centos 7 or ubuntu installations you are running are KVM as well and working as expected?

    Yup this is what make this problem 'strange'

    From what template/ISO are you installing?

    I download iso from centos mirror, 6.8 32 bit, from ovh france

    I have to admit I am much more into debian/ubuntu than centos, but that very last part on the online.net page seems to cover the settings, mind sharing how your config files of that guest looked like (if possible)?

    Let's say I get this IP from online.net

    host IP: 163.111.111.111
host gateway: 163.111.111.1
guestIP: 212.111.111.111
guest VMAC: 50:50:50:50:50:50

    And this is my centos 6 config

    DEVICE=eth0
TYPE=ethernet
UUID=some long string
ONBOOT=YES
NM_CONTROLLED=no
BOOTPROTO=no
HWADDR=50:50:50:50:50:50
IPADDR=212.111.111.111
NETMASK=255.255.255.255
GATEWAY=163.111.111.1
DNS1=8.8.8.8
DNS2=8.8.4.4
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes

    I think this config is similiar with hetzner proxmox?

    are you told of another gateway for that additional IP or is there none given? (I never used additional IPs with online.net so far)

    The gateway is the dedicated server main gateway (163.xxx.xx.1)

    I do prefer the hetzner-like setup with pointopoint and /32 subnet mask on the hostnode as wall as I did run into less trouble with that ;-)

    The problem is I cannot find how is pointopoint in centos 6 like. Are the different host configuration between hetzner and online.net can make some problem?

    and you could always try to switch to a routed setup, which should work, even if you don't have a virtual mac assigned to your additional IP.

    Does hetzner have tutorial like this for centos guest?

    https://wiki.hetzner.de/index.php/Proxmox_VE/en

    Thanked by 1Falzo
  • FalzoFalzo Member
    edited September 2016

    akhfa said: I don't see centos configuration on online.net proxmox tutorial. One long night searching and the solution is on the end page of what tutorial I follow. Aaahhh this is funny :D

    no worries, everyone does overlook some things sometimes ;-)

    most likely this is all about the netmask setup. with different subnets for the gateway and IP you need to choose netmask as 255.255.255.255 and add a direct route to the foreign gateway IP.

    this is achieved by the last part in that online.net tutorial for centos (you finally found) or via adding a default route in the debian/ubuntu setup.

    the pointopoint setup shown at hetzner is another way to do exactly the same with debian, but without the need to use route add - I can't tell if there is something similar for centos.

    akhfa said: Does hetzner have tutorial like this for centos guest?
    https://wiki.hetzner.de/index.php/Proxmox_VE/en

    not that I am aware of, but thanks to you I added that online.net tutorial to my favorites to be able to refer to this one next time ^^

    glad you finally figured out the missing piece and made it work at all ;-)

    Thanked by 1akhfa
  • akhfaakhfa Member

    Falzo said: most likely this is all about the netmask setup. with different subnets for the gateway and IP you need to choose netmask as 255.255.255.255 and add a direct route to the foreign gateway IP.

    The good side about Centos 7 installer is it can detect this automatically, so it can connect into network when installing progress. I didn't find this on Ubuntu server 16.04.1

  • FredQcFredQc Member
    edited January 2017

    Sorry for necroing this thread but just want to say

    to @akhfa and @Falzo

    I had to setup an Centos 6.8 KVM on Proxmox and they literally saved my ass today!

    That's all :-)

    Thanked by 2Falzo akhfa
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