How to verify Link Configuring and Vnet Settings on LDOMS

There are two basic components involved in virtual networking for LDoms: Virtual switches and virtual network devices.  The virtual switch should be seen just like a real ethernet switch.  It “runs” in the service domain and moves ethernet packets back and forth.

A virtual network device is plumbed in the guest domain.  It corresponds to a physical network device in the real world.  There, you’d be plugging a cable into the network port, and plug the other end of that cable into a switch. In the virtual world, you do the same.

You create a virtual network device for your guest and connect it to a virtual switch in a service domain.  The result works just like in the physical world, the network device sends and receives ethernet packets, and the switch does all those things ethernet switches tend to do.


Below Procedure is the Overview of verifying Link Configuration and vnet settings on ldoms

1. Make sure mac address assigned to vnet/vsw by ldom manager is registered in the DHCP server

#  /opt/SUNWldm/bin/ldm list-domain -o network primary


primary-vsw0     00:21:28:16:d8:5c       e1000g0      switch@0   1                1
primary-vsw1     00:14:4f:c9:e3:ba       nxge0        switch@1   1                1   ——–
# /opt/SUNWldm/bin/ldm list-domain -o network ldom01





vnet0 primary-vsw0@primary network@0 00:14:4f:f8:e2:d9 1 vnet1 primary-vsw1@primary network@1 00:14:4f:f8:c9:7e hybrid 1

above mac addresses highlighted in bold must be registered in DHCP server. vnet1 is configured
as hybrid as nxge0 is capable of supporting hyrbid feature. vnet0 is not in hybrid mode

2. Check the link status of the physical interface in control domain/service domain

# kstat -m nxge -i 0 -n “Port Stats” | grep link_       

link_asmpause   0      link_duplex                     full        link_pause      0        link_speed                      10000        link_up         1
# dladm show-dev
vsw0               link: unknown   speed: 1000  Mbps        duplex: full
vsw1               link: unknown   speed: 10000 Mbps       duplex: full
nxge0              link: up             speed: 10000 Mbps       duplex: full
e1000g0         link: up             speed: 1000  Mbps        duplex: full
e1000g1         link: unknown   speed: 0        Mbps        duplex: half
e1000g2         link: unknown   speed: 0        Mbps        duplex: half
e1000g3         link: unknown   speed: 0        Mbps        duplex: half

Above data shows nxge0 link is up

3. Check Below vnet configuation files are created

  • /etc/hostname.vnet0  fils
  • /etc/hostname.vnet1 files

# ifconfig -a
lo0: flags=2001000849<UP,LOOPBACK,RUNNING,MULTICAST,IPv4,VIRTUAL> mtu 8232 index 1
        inet netmask ff000000
vnet0: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 2
        inet netmask fffff800 broadcast
        ether 0:14:4f:f8:e2:d9
vnet1: flags=1000843<UP,BROADCAST,RUNNING,MULTICAST,IPv4> mtu 1500 index 3
        inet netmask ffffff00 broadcast
        ether 0:14:4f:f8:c9:7e

  • The hybrid resource(vnet1) above is assigned only when a vnet is plumbed.That means, the DMA resources are not wasted for a virtual network device that is not currently active.
  • OBP doesn’t use Hybird I/O, that means, the boot net type of traffic in OBP doesn’t benefit from Hybrid I/O.
  • Guest Domain to Guest Domain communication in the same system does not use Hybrid I/O

4. Check communication between vnet and control domain is working

# date; kstat -m vnet -i 0 | grep dring
Sun Aug 23 18:27:09 PDT 2009
        dring_data_acks                    17007
        dring_data_msgs                   17007
        dring_stopped_acks              17007
# date; kstat -m vnet -i 0 | grep dring
Sun Aug 23 18:27:12 PDT 2009
        dring_data_acks                   17014
        dring_data_msgs                  17014
        dring_stopped_acks             17014




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