[SOLVED] CentOS 6 networking and Hyper-V

The post describes a CentOS 6.2 minimal setup running on Hyper-V and mentions a boot-time warning about eth0 dropping NETIF_F_SG because no checksum feature is available. It treats that warning as a virtual-interface issue and moves on to the network setup itself.

The configuration uses a single ifcfg-eth0 file with a static IP, then hard links are created in the other CentOS network directories to match how the scripts work. After that, the hostname is set, /etc/sysconfig/network is edited with NETWORKING=yes, HOSTNAME, and GATEWAY, permissions are set to 644, the system is rebooted, and /etc/resolv.conf is updated with a nameserver.

Reading notes

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• The lab uses Windows Server 2008 R2 SP1 with Hyper-V enabled, CentOS 6.2 x64 minimal ISO, and Linux Integration Services for Hyper-V 3.2.
• A boot message appears in dmesg and messages saying eth0 is dropping NETIF_F_SG because no checksum feature is available.
• The post treats the missing checksum offload feature as a virtual hardware limitation rather than a blocking problem.
• A static interface file is created at /etc/sysconfig/network-scripts/ifcfg-eth0 with DEVICE, BOOTPROTO=static, ONBOOT=yes, NETWORK, NETMASK, and IPADDR.
• The earlier copy-and-permissions method is replaced by hard links to /etc/sysconfig/networking/devices/ifcfg-eth0 and /etc/sysconfig/networking/profiles/default/ifcfg-eth0.
• The machine name is set with hostname my-system-name.
• /etc/sysconfig/network is filled with NETWORKING=yes, HOSTNAME=my-system-name, and GATEWAY=192.168.1.1.
• The file /etc/sysconfig/network is set to permission 644.
• The system is rebooted after the network files are in place.
• /etc/resolv.conf gets nameserver 192.168.1.1 for name resolution.