in ESXi 4,Centos get "connect network is unreachable" ,but xp is ok.

[loveesxi]

hello,

I have a ESXi 4.0 server.

I install a windows Xp in ESXi.the xp work fine.

and I install Centos 5.5 in ESXi.the centos network can't work.when I ping any ip,I get "connect network is unreachable".

when I exchange the ip address ,the xp still fine,and the centos still can't ping.

this is my centos /etc/sysconfig/network-scripts

1. Advanced Micro Devices 79c970

DEVICE=eth0

BOOTPROTO=none

BROADCAST=209.xxx.31.255

HWADDR=00:0C:29:09:1D:43

IPADDR=209.xxx.26.x (x is my ip)

NETMASK=255.255.248.0

NETWORK=209.xxx.24.0

GATEWAY=209.xxx.32.1

ONBOOT=yes

TYPE=Ethernet

how can fix?

please help me,thank you very much!

Message was edited by: Moderator to mask IP addresses.

[athlon_crazy]

Do you get any error when restarting the network? Have you try with E1000 virtual nic instead?

vcbMC-1.0.6 Beta

vcbMC-1.0.7 Lite

[loveesxi]

hello,

thank you very much!

I have try E1000,and restart network.

but I still can't ping in Centos.

[juanqui]

I am having the same issues with CentOS. Has anyone figured this problem out yet? I have tried changing the NIC from "Flexible" to "E1000" as well but no luck. The weird thing is that if I fiddle around with the network settings and restart it a few times it will work and keep on working until the next reboot.

[iyogee]

Hi,

I am facing the same issue on a fresh install.

Using ESXi/vSphere 4.1 and Centos 5.5 (both x_86_64 on Quad Xeon 3440 with HT).

Both the NICs are Broadcom Netxtream.

Thanks.

[iyogee]

Could you please tell us - What kind of tweaks make it work for you? Thanks.

[golddiggie]

I have zero issues with CentOS 5.x on ESXi 4.x... I didn't have any issue while running 4.0. or now that I'm on 4.1...

I would suggest making sure all your network configuration settings are correct. Try using DHCP to make sure you're not missing something, or mistyped something. I would also Deactivate then Activate the network device (System\Administration\Network item). Restart the Network service too. I would also make sure that IPv6 is not in use on the VM. You can also use the 'probe' button to make sure the VM's MAC address is a match to what ESXi is using.

I'm using the 'flexible' NIC on my CentOS 5.x VM's... I did run the additional commands post VMware Tools install (as posted when you run the tools from a terminal window)... If you didn't do those additional settings, I would suggest going back and doing them.

Just for giggles, did you install the virtualization components in CentOS 5.5?? If so, either disable them, or reinstall without them... I do a custom install and make sure to not select those items (I'm not going to nest VM's on the CentOS VM), making sure I do select the other components that I need/want...

Network Administrator

VMware VCP4

Consider awarding points for "helpful" and/or "correct" answers.

[virtualeye]

Disabling ipv6 in ESXi networking fixed this issue on my end (had to reboot ESXi). ipv6 may come in handy though, would be nice to not have to disable this system-wide, how to do within CentOS VM??

CentOS 5.5

ESXi 4.1

Obviously, make sure your network-scripts for ethX are accurate.

I'm using default E1000 ethernet adapter.

[golddiggie]

Via the CentOS 5.5 GUI, if you double click on the 'Active' device in the Network Configuration window (menu: System\Administration\Network) it will produce the 'Ethernet Device' window. Within that window, the third check box is "Enable IPv^ configuration for this interface"... I typically leave this unchecked.

While IPv6 may be good for the world at large, on LAN's (except for very large ones) I still don't see it making sense (or being used)...

I've attached a screen shot so you can actually see both setting windows...

Network Administrator

VMware VCP4

Consider awarding points for "helpful" and/or "correct" answers.

[virtualeye]

Right, that would work if I did not have a minimal install ;--)

This will be a LAMP server, so no GUI.

No big deal, if IPv6 is not needed outside of large, corporate level setups, I can live without it, just a couple of servers on my LAN living behind a switch and base ASA 5505 in NAT.

Learning a ton, and the hard way, lol, the IPv6 disable idea was a god send, had been locked out of my backup server until disabling IPv6 gave my CentOS VM network access and thereby, local SSH access to my backup server, yikes, decent programmer, lousy sysadmin...

BTW, what are the real benefits of IPv6? Could probably keep IPv6 enabled on ESXi and disable in CentOS via command line...

[juanqui]

Hey guys, I have already set up my CentOS 5.5 machine without IPV6, I'm almost using the flexible NIC (I have already tried all the others), I have checked the MAC address, and I have even tested different operating systems. I am having a similar issues with Windows Server 2008 as well. At first I thought it was the network I was using at my colo provider, but they guarantee me that there's no problem with the network. This does not happen very often, but three or four times during the day I notice that I loose connection to some VMs for about 2 to 3 seconds.

My physical NIC is an Intel Corporation 82574L (Gigabit). My physical machine (running ESXi 4.1) is running on a different subnet than the VMs.Also what is the effect of the "Observed IP ranges". It reports "None" for "Observed IP ranges" for my physical NIC on the ESXi server.

Thanks!

[golddiggie]

Some info found herefor going via CLI/terminal commands... Scroll down to the section "8. How do i disable IPv6?"... Copied here for your convienience...

• Edit /etc/sysconfig/network and set "NETWORKING_IPV6" to "no"

• Add the following to /etc/modprobe.conf :

alias ipv6 off

alias net-pf-10 off

• Run /sbin/chkconfig ip6tables off to disable the IPv6 firewall

• Reboot the system

Alternative (which might be easier and works on any release with /etc/modprobe.d):

1. touch /etc/modprobe.d/disable-ipv6

1. echo "install ipv6 /bin/true" >> /etc/modprobe.d/disable-ipv6

• With the 5.4 update symbol/ipv6 module dependency capabilities have been introduced; therefore, if IPv6 has been previously disabled as above an upgrade to the bonding driver in 5.4 will result in the bonding kernel module failing to load. For the module to load properly use instead:

1. touch /etc/modprobe.d/disable-ipv6

1. echo "options ipv6 disable=1" >> /etc/modprobe.d/disable-ipv6

Network Administrator

VMware VCP4

Consider awarding points for "helpful" and/or "correct" answers.

[iyogee]

Thanks for those pointers. I have made sure that the configuration is matched to your description.

One thing I noticed in Configure Management Console is that both the adapters (vmnic0 and vmin1) show the "used by" field as "None" Could it be a problem? I checked the networking configuration from the vSphere client and both NICs show as teamed on vSwitch.

What am I missing here? (also see attached screenshot).

[golddiggie]

You mean "UNused Adapters: None"?? Adapter details won't populate unless you click on one of the listed items (* Adapters)...

As a general rule, we set the Policy Exceptions to "Reject" under all three items. Unless you actually NEED to use one of those, I would suggest doing the same...

I would also suggest using a different vSwitch for the actual VM Network traffic... I'm using four of the six NIC's inside my host (well, there are seven, but I'm not using the onboard Broadcom anymore since it doesn't support jumbo frames)...

Network Administrator

VMware VCP4

Consider awarding points for "helpful" and/or "correct" answers.

[juanqui]

Any ideas why my NIC shows "None" for "Observed IP Ranges" in the management console of ESXi?

[golddiggie]

What are you using for DNS, DHCP, etc? What kind of physical network switch are you using?

I have a VM that's my AD DC, providing DNS and DHCP duties... I'm also using a HP ProCurve 2510G-24 switch (fully managed with CLI)... I do get IP ranges reported on the active NIC's (standby NIC's show 'None', as I would expect)... Actually, looking a bit more, I do see that only the vSwitches that are used by VM's list IP ranges. Since the others are not using DHCP, there's no need to look at ranges... The NIC's without any vSwitches assigned to them, are on the LAN, just not yet configured (reserving them for iSCSI)...

Network Administrator

VMware VCP4

Consider awarding points for "helpful" and/or "correct" answers.

[iyogee]

Alright, moving VMs to a separate switch did it. Thanks so much for your useful tips. Now, I have VM Network (and( VMkernel Port/ Management Network) on the on-board Broadcom Gigabit NIC and VM Network 2 (which has CentOS 5.5 and other VMs) on vSwitch1 on VM Network 2).

Although it is in bridge mode (pulling IP from physical router) and I would prefer to have a private address (NAT).

Question now is, if my storage ( 1TB SATA) is created as a Datastore on VMkernel, would I need to do anything to enable network traffic between these two vSwitches and VM Networks?

Thanks again.

[juanqui]

One of the VM running on my Hypervisor is my DNS server (It's running on CentOS 5.5). Right now my colo only supplies me with a single ethernet link from his switch (I don't know the details of this switch, I am going to ask today). This ethernet link is then connected to a DLINK 12 port gigabit switch (cheap -- sub $100 layer 2 switch). From this switch I have two more ethernet cables, one going to my hypervisor's NIC0 and another one going to the IPMI interface. All IPs I am given are public IPs. Any ideas? Thank you very much for your help btw!