Advanced Networking Configuration

The confignetwork postscript can be used to configure the network interfaces on the compute nodes to support VLAN, BONDs, and BRIDGES. In order to use the confignetwork postscript, the following attributes must be configured for the node in the nics table:

  • nicips
  • nictypes
  • nicnetworks
  • nicdevices - resolves the relationship among the physical network intereface devices

The following example set the xCAT properties for compute node cn1 to achieve the following network configuration using the confignetwork postscript:

  • Compute node cn1 has two physical NICs: eth2 and eth3
  • Bond eth2 and eth3 as bond0
  • From bond0, create 2 VLANs: bond0.1 and bond0.2
  • Make bridge br1 using bond0.1 with IP (10.0.0.1)
  • Make bridge br2 using bond0.2 with IP (20.0.0.1)

Define attributes in the nics table

  1. Using the mkdef or chdef commands

    1. Compute node cn1 has two physical NICs: eth2 and eth3

      chdef cn1 nictypes.eth2=ethernet nictypes.eth3=ethernet

    2. Define bond0 and bond eth2 and eth3 as bond0

      chdef cn1 nictypes.bond0=bond \
          nicdevices.bond0="eth2|eth3"

    3. Fom bond0, create 2 VLANs: bond0.1 and bond0.2

      chdef cn1 nictypes.bond0.1=vlan \
          nictypes.bond0.2=vlan \
          nicdevices.bond0.1=bond0 \
          nicdevices.bond0.2=bond0

    4. Create bridge br1 using bond0.1 with IP (10.0.0.1)

      chdef cn1 nictypes.br1=bridge \
          nicdevices.br1=bond0.1 \
          nicips.br1=10.0.0.1 \
          nicnetworks.br1="net10"

    5. Create bridge br2 using bond0.2 with IP (20.0.0.1)

      chdef cn1 nictypes.br2=bridge \
          nicdevices.br2=bond0.2 \
          nicips.br2=20.0.0.1 \
          nicnetworks.br2="net20"

  2. Using an xCAT stanza file

    • Prepare a stanza file <filename>.stanza with content similiar to the following:

      # <xCAT data object stanza file>
cn1:
  objtype=node
  arch=x86_64
  groups=kvm,vm,all
  nicdevices.br1=bond0.1
  nicdevices.br2=bond0.2
  nicdevices.bond0.1=bond0
  nicdevices.bond0.2=bond0
  nicdevices.bond0=eth2|eth3
  nictypes.eth2=ethernet
  nictypes.eth3=ethernet
  nictypes.bond0=bond
  nictypes.bond0.1=vlan
  nictypes.bond0.2=vlan
  nictypes.br1=bridge
  nictypes.br2=bridge
  nicips.br1=10.0.0.1
  nicips.br2=20.0.0.1
  nicnetworks.br1=net10
  nicnetworks.br2=net20

    • Using the mkdef -z option, define the stanza file to xCAT:

      cat <filename>.stanza | mkdef -z

  3. Using tabedit to edit the nics database table directly

    The tabedit command opens the specified xCAT database table in a vi like editor and allows the user to edit any text and write the changes back to the database table.

    After changing the content of the nics table, here is the result from tabdump nics

    # tabdump nics
#node,nicips,nichostnamesuffixes,nichostnameprefixes,nictypes,niccustomscripts,nicnetworks,nicaliases,nicextraparams,nicdevices,comments,disable
"cn1","br1!10.0.0.1,br2!20.0.0.1",,,"br1!bridge,eth2!ethernet,eth3!ethernet,bond0.2!vlan,bond0!bond,br2!bridge,bond0.1!vlan",,"br1!net10,br2!net20",,,"br1!bond0.1,bond0!eth2|eth3,bond0.2!bond0,bond0.1!bond0,br2!bond0.2",,

Add network object into the networks table

The nicnetworks attribute only defines the nic that uses the IP address. Other information about the network should be defined in the networks table.

Use the chdef command to add/modify the networks in the networks table

chdef -t network net10 net=10.0.0.0 mask=255.0.0.0 mgtifname=eth0
chdef -t network net20 net=20.0.0.0 mask=255.0.0.0 mgtifname=eth1

Add confignetwork into the node’s postscripts list

Using below command to add confignetwork into the node’s postscripts list

chdef cn1 -p postscripts=confignetwork

During OS deployment on compute node, confignetwork will be run in postscript. If the compute node has OS, use updatenode command to run confignetwork

updatenode cn1 -P confignetwork