1. technology and computing
2. hardware
3. computer networking
4. router

Module 5 - Introduction to XenServer
Networking
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Table of contents
Scenario .................................................................................................................................................................................... 3
Exercise 1: Create External and Internal Networks .................................................................................................................. 4
Exercise 2: Add a Virtual Network Interface to Virtual Machines .......................................................................................... 12
Exercise 3: Manage and Review Networks and Network Interfaces via the CLI .................................................................... 21
Exercise 4: Configure a Bonded Interface .............................................................................................................................. 38
Exercise 5: Configure OpenvSwitch and DVSC (Distributed Virtual Switch Controller).......................................................... 51
Exercise 6: Capture a Network Trace ..................................................................................................................................... 73
Exercise 7: Initiate Emergency Network Reset ....................................................................................................................... 86
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Scenario
You work for an Infrastructure as a Service (IaaS) provider and have been tasked with the
configuration of the virtualization infrastructure using XenServer.
The base installation of XenServer has been completed and you have configured the storage
requirements for the environment. You are now tasked with configuring the network system.
The requirements are
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Exercise 1: Create External and Internal
Networks
Overview
In this exercise we will create external networks that allows access to and from the host,
internal networks that allow for communication within a host (host-only), and VLAN networks
that tag traffic leaving the network with VLAN tag to create virtual networks between hosts.
Step by step guidance
Estimated time to complete this lab: 10 minutes.
Step
Action
Create an External Network in XenCenter
1.
Using XenCenter select your pool node and click the Networking tab
2.
Click Add Network
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3.
Select External Network and click Next
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4.
Type New External Network in the Name field and click Next
5.
Select NIC 1 from the NIC drop-down menu
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6.
Select Automatically add this network to new virtual machines and click
Finish
7.
Confirm the new external network has been created.
8.
9.
Note: any virtual machine that is connected to New External Network will be able
to send traffic outside of the host using the NIC 1 interface.
Create a Single Server Private Network via CLI
Connect to vXS01 via SSH
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10.
Create a Single Server Private Network via the CLI:
xe network-create name-label=’SS Private Network’
11.
Switch to XenCenter and confirm the creation of the SS (single server) network
in the pool Networking tab
12.
13.
Note: any virtual machine that has a connection to this network will be able to
communicate with any other VM on this network on the same host.
Create a VLAN Network via CLI
Create a new network for use with the VLAN. The UUID of the new network is
returned:
xe network-create name-label=VLAN888
Note: you will refer to the output UUID in a future step
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14.
Use the pif-list command to locate the UUID of the PIF object that corresponds to
the eth2 device:
xe pif-list
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15.
Create a pool wide VLAN network by specifying the desired, network, physical
PIF, and VLAN tag.
xe pool-vlan-create network-uuid=<VLAN888_network_uuid from step 13>
pif-uuid=<pif_uuid> vlan=888
Note: a new PIF object is created for each server in the pool (3) and the UUID of
this object is returned. These PIFs are then plugged into the VLAN888 network.
A uuid is normally entered with the above command. Rather than typing the
long uuid of the bond (2c7d4b98-c7e5-2347-07c0-3a3e83c4354e in the
example here) you can use <Tab> completion to enter the uuid for you.
16.
Switch to XenCenter and confirm the creation of the VLAN888 network in the
pool Networking tab.
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17.
Confirm the VLAN888 networking is attached to NIC2, which represent eth2
Key
takeaways
Notes
The key takeaways for this exercise are:
 You will be able to create an external network
 You will be able to create an internal network
 You will be able to create a VLAN network
Network Objects Recap:
• A PIF, which represents a physical NIC on a XenServer host. PIF
objects have a name and description, a globally unique UUID, the
parameters of the NIC that they represent, and the network and
server they are connected to.
• A VIF, which represents a virtual NIC on a virtual machine. VIF
objects have a name and description, a globally unique UUID, and
the network and VM they are connected to.
• A network, which is a virtual Ethernet switch on a XenServer host.
Network objects have a name and description, a globally unique
UUID, and the collection of VIFs and PIFs connected to them.
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Exercise 2: Add a Virtual Network Interface to
Virtual Machines
Overview
In this exercise we will
Step
Action
1.
Using XenCenter select your Demo Linux 2 VM
2.
Select the Networking tab
3.
Click Add Interface…
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4.
From the Network dropdown select VLAN888
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5.
Leave the MAC Address auto generated.
Note: manually specifying a MAC is useful in situations where the MAC needs
to be known prior to VM interface creation e.g. for licensing purposes. This does
however carry a risk as any manually mistake can cause communication
problem.
6.
QoS settings can limit the amount to data an interface can send. Leave this
setting default for now.
7.
Click Add
8.
Confirm the interface has been created.
9.
Select the Console tab and log in if required
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10.
Confirm the new network adapter has been detected.
ifconfig
11.
Switch to the Networking tab
12.
Select the new interface on the VLAN888 network
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13.
Click Deactivate
14.
Switch to the Console
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15.
Confirm the interface has been deactivated
ifconfig
16.
Select the Networking tab
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17.
Select the new/2nd interface and click Activate
18.
Confirm the interface is activated and redetected using ifconfig
19.
Select the Networking tab
20.
Ensure the VLAN888 virtual NIC is selected
21.
Click Properties
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22.
Select Enable QoS limit of: and set it to 100 Kbytes/s
23.
Note: this setting will limit the amount of data that the VM can send. It does not
limit the amount of data the VM can receive.
Click OK
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24.
Next we will remove the newly added virtual NIC. Highlight the VLAN888 virtual
NIC and click Remove
25.
Review and click Yes the warning message.
26.
Switch to the Console tab and confirm the virtual NIC has been removed using
ifconfig.
Note: if no interfaces are listed restart the network service.
Key
takeaways
The key takeaways for this exercise are:
 You will be able to add and remove a network interface to a virtual
NIC
 You will be able to deactivate and reactivate a virtual NIC
 You will be able set QoS properties on a virtual NIC
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Exercise 3: Manage and Review Networks
and Network Interfaces via the CLI
Overview
Listing, reviewing, and managing networking configuration information is a critical skill
required to support XenServer.
In this exercise we will list and review the networking objects for XenServer. You will correlate
the relationship between networking object from a Dom0 (CentOS) and XAPI (Xen API and
xe command) perspective. You will also familiarize yourself with command XAPI and OVS
networking commands.
Step by step guidance
Estimated time to complete this lab: 20 minutes.
Step
Action
1.
Using PuTTY, connect to vXS01
2.
Verify the current network backend for the host/pool:
xe host-list params=software-version | grep backend --color
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3.
Locate the network_backend field from the output to confirm the current
network stack:
Note: from the output we can see that all 3 server in the pool are set to
openvswitch.
 network_backend: openvswitch - default
 network_backend: bridge – Linux bridge
4.
List the and review OVS version for the host:
ovs-vswitchd –V
Note: For additional details on the changed between versions, review the
release notes/news on openvswitch.org.
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5.
List and review general OVS information:
ovs-vsctl list open_vswitch
Note: the output provides versioning information for openvswitch and
XenServer
6.
Confirm the status of the openvswitch service is running:
service openvswitch status
Note: the output indicates the status of the database, vswitch deamon, and
XAPI sync service.
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7.
List the network interface information as seen by dom0 (CentOS):
ifconfig
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8.
List the NIC objects as seen by XAPI using xe:
xe pif-list
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9.
List specific parameters for all physical interfaces (PIFs) in the pool.
xe pif-list params=host-name-label,uuid,device,network-name-label
10.
List specific parameters for all virtual interfaces (VIFs) in the pool.
xe vif-list params=vm-name-label,uuid
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11.
List specific parameters for the networks in the pool:
xe network-list params=bridge,name-label,VIF-uuids,PIF-uuids,uuid
Note: the VIF-uuids represent the virtual machine NIC interfaces connected to
the network.
12.
Change a parameter on a network object:
xe network-param-set name-description='Virtual LAN network with tag
888' uuid=<UUID of VLAN888 network object>
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13.
Switch to XenCenter and confirm the network description has been added.
14.
Remove a parameter on a network object:
xe network-param-clear param-name=name-description uuid=<UUID of
VLAN888 network object>
Note: the same process can be applied to most XenServer objects.
15.
Confirm the network description has been removed using XenCenter.
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16.
List and review the virtual switches configured on the host:
ovs-vsctl show
Note: this command provides a list of bridges, ports on the bridge, and
interfaces associated with port. An OVS virtual switch is represented by a
bridge.
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17.
List and review detailed information the bridges configures on the host:
ovs-vsctl list bridge
Note: take special note of the output field for external-ids and ports.
18.
List and review the XenServer Network associated with bridge:
xe network-list uuid=<UUID of a “xs-network-uuids” parameter from ovsvsctl list bridge output>
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19.
List and review the port information for the bond0 bridge:
ovs-vsctl list port xenbr0
Note: take note of the interfaces field
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20.
List and review the information for one of the interfaces forming part of the
bond:
ovs-vsctl list interface <UUID of interface>
Note: this output provides interface statistics
21.
List and review the current flow (rule) entries held in the userspace databse:
ovs-appctl fdb/show xenbr0
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22.
Lists and review datapath information held in the kernel module:
ovs-dpctl show
Note: the “hits and misses” field indicate whether a flow/packet rule was located
in the kernel flow table (hit) or whether the userspace database needed to be
queried (miss).
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23.
Dump and review the current flow entries held in the kernel module tables:
ovs-dpctl dump-flows xenbr0
Note: each in-port entry represent a flow in the kernel module which includes
the src and dst information, traffic type, and action rules.
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24.
Dump and review more readable and formatted information contained in the
OVS database:
ovsdb-client dump | less –S
Note: press q to quit the less tool
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25.
Dump and review all database logging information:
ovsdb-tool show-log -mm /etc/openvswitch/conf.db
Note: this command prints a summary of the records in the database log,
including the time and date at which each database change occurred and any
associated comments. This may be useful for debugging.
Key
takeaways
The key takeaways for this exercise are:
 You will be able to list and confirm which network stack is enabled on the
host.
 You will be able to confirm the status of the openvswitch service.
 You will be able to view the network configuration as seen from Dom0
perspective.
 You will be able to view the network configuration as seen from XAPI
perspective.
 You will be able to view the change object parameters.
 You will be able to list and review detailed networking information using XE
and the OVS command set.
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Notes

Using OVS command line options for configuration purposes is not
supported. The vSwitch should only be configured using XenCenter, xe
CLI, xsconsole, and the Distributed vSwitch Controller. The commands
shared here are for data collection and diagnostic purposes only.
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Exercise 4: Configure a Bonded Interface
Overview
NIC bonds, sometimes also known as NIC teaming, improve XenServer host resiliency
and/or bandwidth by enabling administrators to configure two or more NICs together so they
logically function as one network card.
XenServer provides support for active-active, active-passive, and LACP bonding modes. The
number of NICs supported and the bonding mode supported varies according to network
stack.



LACP bonding is only available for the vSwitch whereas active-active and activepassive are available for both the vSwitch and Linux bridge.
When the vSwitch is the network stack, you can bond either two, three, or four NICs.
When the Linux bridge is the network stack, you can only bond two NICs.
In this exercise you bond two interfaces into a pool-wide SLB bond, change the bond mode to
Active-passive and LACP. You will also see the status of the connections using Open
vSwitch commands.
Step by step guidance
Estimated time to complete this lab: 20 minutes.
Step
Action
In XenCenter select the pool node
1.
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2.
Select the Networking tab
3.
Click Add Network…
4.
Select Bonded Network and click Next
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5.
Select NIC 1 and NIC 2 from the available NICs
6.
Ensure the Bond Mode is set to Active-active
7.
Leave the MTU size default and Automatically add this network unchecked
8.
Click Finish
9.
Review the warning message and click OK
10.
Select the Notifications node in XenCenter and monitor the bond creation
process.
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11.
When completed successfully select the Infrastructure node and confirm the
Bond1+2 network was created.
12.
Notice the associated interface for VLAN888 has changed from NIC 1 to
Bond1+2.
13.
Switch to your SSH connection to vXS01
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14.
Review the bonds in the pool:
xe bond-list
Note: a bond interface/object will be listed for each host in the pool.
15.
Review all parameters of each bond in the pool:
xe bond-list params=all
Note: the mode (RO) field indicating that the current load balancing mode is
balance-slb (Source Level Balancing)
16.
Switch to XenCenter and select the Bond1+2 network
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17.
Click Properties
18.
Select Network Settings
19.
Select Active-passive bond mode and click OK
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20.
Switch to your SSH (PuTTY) connection to vXS01
21.
Again list all parameters of each bond in the pool:
xe bond-list params=all
Note: the mode (RO) field indicating that the current load balancing mode is
active-backup
22.
Switch to XenCenter and select the Bond1+2 network
23.
Click Properties
24.
Select Network Settings
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25.
Select LACP with IP load balancing bond mode and click OK
26.
Switch to your SSH connection to vXS01
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27.
Again list and review all parameters of each bond in the pool:
xe bond-list params=all
Note: the mode (RO) field indicating that the current load balancing mode is
lacp (Link Aggregation Control Protocol)
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28.
Review the properties (MRO) field for the LACP bond configuration.



29.
hashing_algorithm: tcpudp_ports – indicates IP based load balancing
is configured.
lacp-fallback-ab: true – indicates this bond will fall back to active backup
mode until the switch is configured for LACP.
lacp-time: slow –
Using openvswitch commands list the bonds for the host:
ovs-appctl bond/list
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30.
Review the configuration information for bond0:
ovs-appctl bond/show bond0
31.
Review the port information for bond0:
ovs-vsctl list port bond0
Note: the output list whether lacp is active, the bond mode, Mac, which
interfaces make up the bond, etc.
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32.
Review the LACP Partner and Actor details status for the host:
ovs-appctl lacp/show
Key
takeaways
The key takeaways for this exercise are:
 You will be able to create bonded interface.
 You will be able to configure an active-active bonded interface.
 You will be able to review bond configurations and status
information.

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Notes



When customers want to connect bonded NICs to multiple switches
and you configured the LACP bonding mode, customers must use
stacked switches. The term stacked switches refers to configuring
multiple physical switches to function as a single logical switch.
LACP bonds require setting the Static Mode setting in the LAG
group to be set to Disabled.
Example of how to create a bond via CLI:
xe bond-create network-uuid=<network_uuid> pifuuids=<pif_uuid_1>,<pif_uuid_2>,<pif_uuid_3>
mode=<balance-slb | active-backup | lacp>
*note the “mode=” parameter is optional and active-active will be the
default balancing mode if not specified.
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Exercise 5: Configure OpenvSwitch and
DVSC (Distributed Virtual Switch Controller)
Overview
In this exercise we will
Step by step guidance
Estimated time to complete this lab: 30 minutes.
Ste
p
Action
Configure a DVSC
1. Using XenCenter select the DVSC virtual appliance.
2. Select the Console tab.
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3. Review the DVSC VM local console message.
Note the important information relating to the graphical console access and remote
management URL.
4. Confirm the DVSC management IP using the Networking tab in XenCenter.
Note: if the IP address information is not displayed, restart the DVSC VM/appliance
5. Switch to the Console tab and log into the shell with U: admin P: Citrix123.
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6. List the shell help information:
help
7. List and review the DVSC management interface configuration:
show controller management-interface
8. Click Switch to Graphical Console.
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9. Enter VNC password Citrix123.
10.Confirm the DVSC management is displayed.
Note: for the best user experience it is recommend to access the management console
using a browser (IE is recommended).
11.Click Switch to Text Console
https:L
12.For the remainder of the lab we will use a browser to manage the DVSC.
13.Launch IE from your landing desktop and navigate to the graphical management IP address
https://192.168.10.13.
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14.Accept any certificate warnings and continue to the management console.
15.Log into the management console.
16.Configure the DVSC to manage your XenServer pool.
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17.Click Add Resource Pool.
18.Enter the management IP address of you pool master, root credentials, tick the Steal
option and click Connect.
19.Wait and confirm the DVSC has successfully connected to the pool by verifying the status is
Green/Connected.
20.The console will automatically refresh. To pause the refresh click the pause button.
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21.Select the Dashboard tab for a site wide view.
Note: a single DVSC can manage multiple XenServer pools.
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22.Select the Settings tab. (if a Network Error is displayed, wait until the connection is reestablished.)
Note: the IP and hostname settings can be reconfigured from this node.
23.Select the Software Version & Updates node.
Note: A DVSC can be upgraded from file. For more information review the XenServer 6.1
download page. This feature however is not widely used.
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24.Select the Server & Certificate Maintenance node.
Note: This node provides mechanism to collect diagnostic logs from the DVSC, update the
SSL certificate, and the OVS certificate.
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25.Select and review the Administrative & Accounts node.
Note: This node can be used to create additional user accounts.
26.Click Create Account
27.Enter a username, select Superuser privileges, and password Citrix123
28.Click Add User
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29.Confirm the new user account has been created.
30.Select and review the Configuration Snapshots node.
31.Select a configuration snapshot and click the options icon and click download.
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32.Download a snapshot of the DVSC configuration.
33.Save the export.gx to your landing desktop.
34.Select and review the Time & NTP node.
Note: Configuring NTP is a critical part of configuring a DVSC, same as with a XenServer
host/pool.
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35.Select and review the Syslog node.
Note: Use this node to configure a remote syslog server to export the system logs to.
36.Select the Visibility & Control node.
37.Expand the All Resource Pools node and select the XenServer pool node.
Note: this node provides pool specific information.
38.An external NetFlow collector can be specified, by default the DVSC will collect and display
NetFlow statistics.
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39.The Fail Mode is configured to Fail-Open by default.
Note: If the pool is configured to Fail-Safe mode no new flows rules will be accepted if the
DVSC should become unavailable.
40.RSPAN can be configure to mirror traffic to a VLAN for monitoring purposes.
41.Expand the Pool-wide Networks node.
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42.Select SS Private Network
43.Select the Access Control tab.
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44.Configure a mandatory policy. Click the configuration dropdown and Add New Mandatory
ACL.
45.Click Save Policy Changes.
46.Configure the ACL, Click allow and Change Action to Deny.
47.Click Any and Use an existing protocol to change the protocol to deny.
48.Select SSH from the protocol list and Use Protocol.
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49.Click Save Policy Changes.
50.This configuration will configure the openvswitch present on each hosts to prevent SSH/port
22 connections over Network 0 (management)
51.Select the Port Configuration tab.
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52.Select Apply a QoS limit of and use the default Kbit/s settings.
Note: if the pool is managed by a DVSC you will not be able to configure the network QoS
settings using XenCenter.
53.Click Save Port Configuration Changes
54.Switch back to the Access Control tab
55.Click the Rule Details radio button to provide more information on the set rule
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56.Delete the ACL rule applied to the network.
57.Click Save Policy Changes.
Note: ACL and QoS settings can be configured on a global, per pool, per server, network,
virtual machine, per physical and virtual interface level.
58.Using Putty connect to vXS01
59.Confirm the current controller information for this host:
ovs-vsctl list controller
Note: the controller state and target details
60.
As the pool is now managed by a DVSC you will create a Cross-Server Private Network
61.Switch to XenCenter and select the pool node
62.Select the Networking tab
63.Click Add Network…
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64.Select the Cross-Server Private Network and click Next
65.Name the network CS Private Network and click Next
66.Select Bond 1+2 from the management interface list
67.Click Finish
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68.Confirm the network was created
Note: the network will remain disconnected until and VM requires the network
69.Select the Demo Linux 2 VM
70.Select the Networking tab
71.Click Add Interface…
72.Select the CS Private Network from the dropdown list
73.Click Add
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74.Confirm the interface has been created
75.Select the pool node
76.Confirm the status of the CS Private Network is now Partially Connected
Note: the network will remain partially connected until a GRE tunnel is required between two
hosts in a pool.
Key
takeaways
Notes
The key takeaways for this exercise are:
 You will be able to configure DVSC via the management shell
 You will be able to launch the graphical console via XenCenter
 You will be able to connect and configure the DVSC via a browser.

For detailed information on the DVSC review the administration guide.
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Exercise 6: Capture a Network Trace
Overview
In this exercise we will capture a network trace on different network interfaces associated
with a XenServer host and the virtual machines running on XenServer.
The first step is to identify the interface that you would like to trace on. Questions to ask
would be if the issue is isolated to a virtual machine, a group of virtual machines or a specific
XenServer. The answer will determine if you will collect a trace on a PIF, VIF or Bridge.
Step-by-step guidance
Estimated time to complete this lab: 20 minutes.
Step Action
1.
2.
Collect a network trace on a physical interface (PIF) used by XenServer via the CLI
Switch to your SSH connect to vXS01
Identify the XenServer host which we will collect the network trace from
xe host-list
Note: in this example only one XenServer host is available
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Step
3.
Action
List the physical interfaces (PIF) detected by XenServer
xe pif-list host-name-label=vXS01
Note: in the above example the host has three NICs (eth0, eth1, and eth2) and a VLAN
888 which is associated with bond0 and is seen as a PIF. The tunnel0 interface represent
the Cross-Server Private Network (GRE tunnel)
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Step
4.
Action
Use tcpdump to collect a trace from eth0 until you have 100+ packets
tcpdump –i eth0 –vvv –w eth0.pcap
Note: to stop the trace press CTRL+C
Note: In the above example we collected a network trace on eth0 and wrote the output to
a file called pif_trace.pcap.
-i = interface
-vvv = very verbose mode
-w = write to file
Note: To capture the complete packed payload use the –s 0 parameter when collecting a
trace.
Note: use .pcap file extension to allow for file type association with network analyzing tools
such as Wireshark.
Collect a network trace on a virtual interface (VIF) used by a virtual machine:
Note: VIF names are dynamically created on VM start. VIF names are constructed with the
following structure; vifx.y where x is the domain id of the VM and y is the device number.
The dynamic part of the name is the domain ID because it may change on VM start.
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Step
5.
Action
List the VIFs device number associated with a VM
xe vm-vif-list vm=Demo\ Linux\ 2
Note: in the above example this VM has two VIFs. Device 0 is connected to Network 0
and Device 1 is connected to the CS Private Network network.
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Step
6.
Action
Locate the domain identifier (domid) for a particular virtual machine
xe vm-list params=name-label,dom-id,uuid
7.
And alternative method to list the domid of the current domains running on your
XenServer is using the list_domains command.
list_domains
Note: this command will list all domains/VMs currently running on this server and their
associated domain identifiers (domid). If there is only dom-id 0 running on your server start
or migrate a VM to vXS01. Also note, this command is also not dependent on xapi.
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Step
8.
Action
Locate the virtual interfaces as detected by dom0
ifconfig
Note: scroll through the output you should see two VIFs associated with domid 17 with
device numbers 0 and 1 (vif17.0 and vif17.1)
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Step
9.
Action
Collect a network trace from the vif17.0 virtual interface
tcpdump -i vif17.0 -vvv -w vif17.pcap
Note: To capture the complete packed payload use the –s 0 parameter when collecting a
trace.
Collect a network trace on a virtual bridge (XENBR) used by a virtual machine:
10.
11.
Note: this process will collect all traffic running over the bridge. Whether or not the data
packet is leaving the host i.e. hitting the wire or not.
List the current bridges
ovs-vsctl list-br
Trace network traffic on a bridge for a couple of seconds
tcpdump -i xenbr0 -vvv -w xenbr0.pcap
Note: to capture the complete packed payload use the –s 0 parameter when collecting a
trace.
Collect the trace files from the XenServer for analysis:
12.
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Step
13.
14.
Action
From the landing desktop connect to the vXS01 using WinSCP
Login using root/Citrix123
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Step
15.
16.
Action
Locate and select the trace files
Note: if the trace files are not displayed click the refresh button
Select the Desktop for your left navigation pane
in the right column.
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Step
17.
18.
Action
Select and drag trace files over to your desktop
Close WinSCP
Open the trace files with a trace analyzer i.e. Wireshark:
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Step
19.
20.
Action
Launch Wireshark from your client machine desktop
Click Open
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Step
21.
Action
Browse to the xenbr0 trace file on your client desktop (copied earlier) and Open
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Step
22.
Action
Open and review the trace.
Note: In the above example we can see the SSH traffic running between the client
(PuTTY) and the XenServer Host.
END OF EXERCISE
Summary
Key
Takeaways
The key takeaways for this exercise are:
 You will be able to identify network interfaces to trace.
 You will be able to capture and collect network traces on different
network interfaces associated with a XenServer host and the virtual
machines.
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Exercise 7: Initiate Emergency Network Reset
Overview
In this exercise we will perform an Emergency Network Reset. Incorrect networking settings
can cause loss of network connectivity, and a XenServer host may become inaccessible via
XenCenter or remote SSH. Emergency Network Reset provides a simple mechanism to
recover and reset a host's networking.
Incorrect settings which could cause a loss of network connectivity could include renaming
network interfaces, creating bonds or VLANs, or mistakes when changing the management
interface (for example, entering the wrong IP address).
Step
1.
Action
Using XenCenter select vXS03 and click Console
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2.
Reset the current management interface to use DHCP using the CLI.
xe-reset-networking
Note: this will cause the host to lose IP addressing and become disconnected
from the pool. This is due to no optional parameters being specified for the
command and so it will assign the first interface as management and IP
addressing via DHCP. For more information refer to the ENR section in the
admin guide.
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3.
Review the warning message, type Yes and press Enter
4.
vXS03 will now appear offline in XenCenter
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5.
Navigate to the virtual machine which is running the vXS03 server and select
the Console tab.
6.
Wait for the server the complete the reboot cycle before proceeding.
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7.
Review the warning message and press Enter
8.
Select Network and Management Interface and press Enter
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9.
Review the current management Interface configuration information
10.
Select Emergency Network Reset
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11.
Enter the root password (Citrix123) and press Enter
12.
Review the warning and Continue
13.
Specify eth0 as the new Management Interface
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14.
Select Static as the IP addressing mode
15.
Enter the following IP address information:




IP address: 192.168.10.23
Subnet mask: 255.255.255.0
Gateway: 192.169.10.1
DNS: 192.168.10.11
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16.
Verify the pool master’s IP address is correct (192.168.10.21) and select OK
17.
Confirm details and press Enter to apply the changes and reboot
18.
The server will reboot with the correct static IP information and reconnect to the
pool.
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19.
Select vXS03 and select the Networking tab and confirm all pool wide networks
have been inherited when re-joining the pool.
Note: the iSCSI SR will display an error we will need to manually log into the
iSCSI server using iscsadm.
Key
takeaways
Notes
The key takeaways for this exercise are:
 You will be able to reset a XenServer host management interface using the
CLI and xsconsole
Here is an example of using the ENR to set a stati IP on a member server and
assuming the master IP has not changed:
xe-reset-networking --mode=static --ip=<ip-address> --netmask-<netmask> \
--gateway=<gateway> --dns=<dns>
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