The Switch Port Management (SPM) features in NetMRI allow at-a-glance management of all switched access interfaces in the network. IT departments routinely under-estimate (and over-estimate) port utilization and capacity requirements. In a large, switched spanning-tree network, some switches can go under-utilized while other switches in the network absorb unacceptably high loads. Switch port utilization trends are difficult to identify–is switch port utilization static, increasing or decreasing? Where are usage trends increasing? Decreasing? If certain switches support hosts that frequently leave their network segment (on business trips, for example) only to return within a week or two, how does the network manager control those temporarily vacated ports so that they remain available for their returning hosts?
Users often confront issues such as rogue/unknown devices on their switched networks, devices that frequently shift between switch segments, and a general lack of ability to track who connects when and where. Lacking adequate capacity planning, users sometimes resort to investing in expensive switch capacity "just to be safe."
NetMRI's Switch Port Management (SPM) page (Network Explorer –> Switch Port Management) solves all of these issues. SPM enables both big-picture and highly focused views of an entire switched Ethernet network, from the overall network layer to individual devices and interfaces. Extending throughout the entire switched network, all endpoints are detected, tabulated and monitored by NetMRI.
NetMRI can perform near-real-time polling of any part of the switched Ethernet network from the distribution level to any LAN switch. Network polling settings can be customized for any device group and administrators can execute a poll of a device group or the entire switched network at any time.
In a large-scale switched network, it can also be difficult to perform basic troubleshooting–locating the affected devices and analyzing their switch-port configuration. Through specialized reports, Switch Port Management gives administrators an integrated tool by which they can quickly learn the switch port settings of the interface to which any given device connects, including line speed, duplex, link status, VLAN ID and other information.
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Note: When you execute port control tasks such as Set Admin Status for an SPM port, NetMRI displays a separate window showing the execution state of the command. In some cases, completion may take some time. NetMRI automatically polls the device at regular intervals to check status and notifies the user when the command completes.
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The following procedure describes the overview of an entire rollout process for Switch Port Management. For brevity, this topic does not describe certain elements in detail. Where necessary, links are given to topics providing more information.
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Note: The switches and switch-routers have already been discovered by NetMRI. Switch Port Management polls switches for a detailed collection of information on switch port connectivity, status of ports and end devices. For information, see Running the Setup Wizard, Configuring Network Discovery Settings and Running Network Discovery on Routed and Switched Networks.
NetMRI gives explicitly licensed devices priority in determining which devices to manage. Unlicensed devices continue to be managed by the appliance, but the appliance periodically collects only basic discovery data. See Other Network View Operations for more information.
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- After performing initial setup and defining your Discovery settings, you must define your global switchport polling settings. Go to Settings icon –> Setup –> Collection and Groups –> Global and click the Switchport Manager side tab to define your switch polling settings. Several primary polling options are offered:
- Periodic Polling: Define regular polling time periods. Choose a polling interval of 1 or more Minutes or Hours. This is the default polling behavior for NetMRI. The default polling interval is 60 minutes;
- Scheduled Polling: Schedule recurrent polling based on hourly, daily, weekly or monthly time periods. Click Add New Schedule and select a Recurrence Pattern of Once, Hourly, Daily, Weekly or Monthly; in all cases you must choose an Execution Time;
- On-demand polling: click Poll Now to immediately begin polling all switch and switch-router devices in the managed network. (Also see Understanding SPM Polling for more information);
- Completely disable switch port polling.
- After defining global polling settings, you can define more specific polling settings at the Device Group level. Go to the topic Device Actions in Switch Port Management for more information.
After some time, polled switch performance and configuration data appears in the NetMRI UI. - Go to Network Explorer –> Switch Port Management.
The left-side menu provides three categories: Devices, Interfaces and End Hosts. - Click any menu item on the left for more information about the
switched devices in the network. Go to the topic Using the Switch Port Management Console for more information.Anchor bookmark237 bookmark237 - For port control, you can set any switched interface to administratively Up or administratively Down by right-clicking the switch interface link and selecting Set Admin Status. You can also assign or change a VLAN assignment for a switch port by right-clicking the switch interface link and selecting Edit VLAN Membership.
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Two hierarchical lists appear in the Switch Port Management page: the Select Device Groups list on the right, and the Devices, Interfaces and End Hosts categories on the left. To begin using the Switch Port Management console, select any device group in the right-side list. Each device group represents a data set from a selected group of network devices. Consider that some device groups (Routing, for example) have systems with ports that will not be managed or catalogued by Switch Port Management.
After selecting a device group on the right, choose a category on the left: Devices, Interfaces or End Hosts. Then choose a menu option from the exploded list. For example, Devices has five menu items.
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Note: The All Devices category is also a device group, and you can get a complete view of the switched network by selecting it.
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The Capacity Summar
y – Ports appears at the top of the Switch Port Management page, indicating several basic pieces of information:Anchor bookmark239 bookmark239
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Note: The number of Available ports will always be less than or equal to the number of Free ports. Trunk, routed and unlicensed ports also are not included in the SPM port counts.
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- Available Ports %: The percentage of all managed switch ports appearing as Available.
- PoE Ports: The count of Cisco switched Ethernet ports running the Power over Ethernet switching protocol for IP telephony applications.
Choosing Devices Present shows the total of all switches' contributions to each of the six capacity categories. Choosing any other device group rewrites the Capacity
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Summary – Ports pane to reflect the subset of values for the selected device group:
Beneath the Capacity Summary– Summary – Ports pane, the Devices Present table appears displaying the data sets for all devices in the chosen data group. Each table row reflects a data set record obtained from LAN switching devices from a process called polling. The Devices Present table designation is for all devices in the chosen data set–not for all devices in the network.
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All tables in the Switch Port Management console provide an
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Clicking the Action icon for any table record in SPM displays a dropdown menu with differing options based upon the network entity type listed in the respective tables.
The Devices, Interfaces and End Hosts data categories provide different Action menus based on the table selection. The following sections describe switch port Actions menu options for each category.
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Switch Port Management (SPM) Date/Period menus enable flexible measurement and reporting for any device, interface or end host. You can effectively go bac
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For any page in SPM, clicking the icon on the top left of the table displays the Select Date/Period menu. The Select Date/Period menu fixes the current SPM page to a specific date or range of dates, going backwards from the current date, using a drop-down calendar.
Calendar dates shown in Green represent an immediately available data set to display in a Switch Port Management table. The most current data in any SPM table (such as the most recent 7 days for the Daily selection) is always available by default and appears highlighted in green. Older data requires the user to wait
while NetMRI generates the requested data as a background task. After generation, the requested date appears in green, indicating the data is instantly available by reloading the page. Any date in the past or in the future appearing in grey that cannot be selected, represents information that is unavailable to the current NetMRI system.
Consider the Device category, with the default time measurement set to Daily.
As an example, you decide to look at the list of network switches that have changed in their status or their configuration over the previous 30 days from the current date. Choose Devices –> Changed Devices, click the Select Date/Period icon, and choose the time period (Daily, Weekly, Monthly, 7-Day or 30-Day). The time window shown in the currently selected page changes to the new value, and the current page changes in a number of ways:
- The Capacity Summary– Summary – Ports pane adjusts to reflect the different data sample, and the Total Ports, Free Ports and other counters may change to reflect new values.
- The chosen time window applies to any further selected pages in Switch Port Management until you change the settings again for the same page or for a different page.
- The chosen time window also applies to any other tables and information charts under Network Explorer, Network Analysis or the Dashboard until you change the value chosen under the Select Date/Period.
You can shift time windows across the calendar. Select a date three weeks previous to the current. Then, choose Period –> 7-Day. The current table redraws to show the currently selected data set. Then, use the Select Date/Period menu to select day three months in the past. The 7-day time window shifts to the new position, with the selected date as the last day in the time window.
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Note: Switch Port Management (and its polling functions) operates only with devices detected as Switches or Switch-Routers in NetMRI. Also see Performing On-Demand Switch Port Polling.
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Network device polling is the key mechanism for building Switch Port Management (SPM)'s switching information, and the polling features provide considerable flexibility. You use polling at the Device Group level to check for changes to any active device in that group. You can define polling time periods for individual device groups so that administrators have near-real-time capabilities for
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In all cases, a polling schedule indicates the start of a polling cycle. Any given network device may not be polled at the specific time when the scheduled polling cycle begins; this is particularly likely when many devices are being polled during the cycle. The duration of a polling cycle may take some time.
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Note: The Settings icon –> Setup –> Collection and Groups –> Global tab provides the appliance-wide settings for polling all Switch and Switch-Router devices in the network.
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NetMRI provides several polling and discovery optimizations under Advanced Settings. See Changing Advanced SPM Settings for details.
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You can apply switch port management polling settings to device groups. These settings, located under the Settings icon –> Setup –> Collection and Groups –> Groups tab, take precedence over the settings defined in the Global tab.
In NetMRI, network polling automatically takes place every 90 minutes. This setting can be lowered to a minimum value of 30 minutes.
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Note: Periodic polling executes at a minimum time period of 30 minutes between polling cycles.
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By default, Switch Port Management polls all known Ethernet switching devices every 60 minutes. This feature is called periodic polling. Polling performance relies on many factors, including the size of the network, link speeds, the number of ports in the switched networks, and other factors. If the appliance cannot complete polling within the specified time period, NetMRI does the following:
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Periodic polling settings can be adjusted globally and within each device group. Periodic polling provides for the following rates: 30/45/60/90 minutes, then every hour up to and including 24 hours.
NetMRI always logs the elapsed polling time period for any network device regardless of the installed license for the current instance.
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Note: Different data collection methods cannot collect polled information from a device at the same time.
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You may exclude device groups from Switch Port Management; the switches within the chosen group will not appear in the Devices page and their switch ports will not count against the SPM interface license count, or in the Capacity Summary– Summary – Ports pane. Switch Port Management will not poll excluded device groups.
Device polling combines with NetMRI's configuration management features (the ability, for example, to quickly pull up and edit a given LAN or distribution switch's configuration files) to provide a workflow to quickly respond to issues in the switched network.
Multiple polling schedules can be applied per device group. For example, a user can schedule polling to run every Sunday at 3AM and 6PM.
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Infoblox recommends regular collection of interface performance statistics for Switch Port Management-managed systems, differing from the irregular or lengthy time periods used by the automatic collection of switch-forwarding data in the full NetMRI configuration. For information on switched interface management, see Managing Interfaces Through Switch Port Management.
Performance polling can be executed immediately, on demand, with limitations. If someone manually attempts to poll a device group when another poll of the entire network is already running, NetMRI notifies the user that another polling session is already in progress and will not execute the manual request until the current session completes.
Infoblox advises regular performance polling because interface-level performance statistics are provided to the appliance as counter values. NetMRI tracks differences in performance counter values from poll to poll and uses the deltas to calculate the true interface performance statistics over that time period. A regular time period provides greater granularity to the performance data and minimizes the changes of counter roll-overs.
For switch port management, interface performance statistics collection applies only to ports in Switch and Switch-Router devices.
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- Display the Switch Port Management table you wish to filter. For example, choose Devices Present.
- Click Filters just above the top of the table.
- In the Select a New Field drop-down list, choose the table field by which to filter. For example, in a long device list, you might choose Avail Ports %.
- Choose an Operator. For example, you might want to check for all switches that have 20% or less of their ports available; in this case the <= operator is appropriate.
- In the Value field of the Filters dialog, enter the numeric value. This is the numeric threshold by which the data is filtered. The result is a filter by which all records with a count of less than 20% will not appear in the filtered table.
- Click Apply to test the filter. The table will refresh in the background. If you wind up with results you don't expect, check your use of the correct operator or change the numeric threshold.
The Capacity
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- Summary – Ports page also redraws to show the matching counts for the filter.
- Click the trashcan (Delete) icon for the filter row to delete a filter. Of course, you can apply more than one filter at a time to the table.
Filter criteria change according to the chosen table information. Devices, Interfaces and End Hosts all present a different set of table fields by which you can filter their respective bodies of information.
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Note: SPM tracks MAC addresses and their associated IP and switch port history. SPM separately maintains an active record of all MACs ever seen by the NetMRI system, along with their associated connectivity information.
Unique identities for all detected End Hosts are established by their respective MAC addresses.
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Open Telnet Session: Uses the Telnet/SSH proxy built-in to NetMRI to start a Telnet session with the selected device. Open SSH Session: Uses the Telnet/SSH proxy built-in to NetMRI to start an SSH session with the selected device.
Topology Viewer: Through a second-level dropdown menu, gives quick access to Layer 2 and Layer 3 views of the network topology surrounding the chosen device. If the selected device is classified as a Switch, only the L2 nHop and L2/L3 Path Viewer topology views are available.
- L2 nHop: Shows the devices that can be reached from a starting device through a given number of Level 2 (actually a hybrid of L1 and L2) connections.
- L3 nHop: Shows devices that can be reached from a starting device through a given number of routed Level 3 connections.
- L3 Path Viewer: Shows the most likely path traffic would take, ignoring Layer 2 connectivity and concentrating on L3 reachability and the "best" path for communication between Layer 3 devices.
- L2/L3 Path Viewer: Shows the most likely path traffic would take between two devices, including both Layer 2 and Layer 3 connectivity.
Also see Using the Topology Viewer for more information on how to use this NetMRI feature.
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Data columns related to interfaces on each device (Free Ports, Available Ports, Available Ports %) provide hyperlinks to the Ports Present table. You can immediately see the operating status and admin status of every port that appears as Free in a given switch.
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Devices are removed from New Devices and join Devices Present at the conclusion of the next polling process.
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A second page under End Hosts, End Hosts Not Present, lists any end host devices that have lost communication with the network.
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Note: SPM port counts in interface tables include only access ports. Trunk ports and routed ports are not counted against access interface counts or against the NetMRI license. Routed ports on switch-router devices will not appear in any Switch Port Management interface counts.
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For an interface, the First Seen and Last Seen timestamps indicate the first occasion when the network switch was polled by Switch Port Management, and the last occasion when the device was polled or otherwise detected on the network.
The Device Name is shown, along with the Interface identifier and a brief Description, its MAC address, operating and administrative status, the Line Speed, and Duplex settings if known and supported.
Several SPM port control settings also appear:
- Set Admin Status–Set – Set the port to administratively Up or administratively Down;
- Edit Description –A – A text label describing the port;
- Edit VLAN Membership –Change – Change the VLAN assignment for a switch interface.
- Choosing a menu option displays a dialog for the port configuration change.
- For Admin Status, ports can be set to Up or Down from the drop-down menu.
- Enter a new text description for the port in the Interface Description field.
- For Edit VLAN Membership, choose the VLAN ID from the VLANID drop-down list (new values are not entered in this location) and the VLAN name from the VLAN Name drop-down list. By enabling the No VLAN checkbox, a port can be set to disable any VLAN assignment.
In all cases, click Save to commit settings.
Also see Using the Interface Viewer for more information on how to use this NetMRI feature set.
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The Ports Present table provides the list of switched access interfaces for the entire network, the aggregate interface list for any chosen device group and the list of interfaces for any chosen LAN switch or distribution switch.
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Note: Sort the Ports Present table by the # End Hosts column to more easily show the switch ports with the highest number of connected hosts.
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The Ports Present table data defaults include the following:
- Action icon: provides the Action menu with View Interface History, Set Admin Status, Edit Description, and Edit VLAN Membership options.
- Device Name: The Ethernet switching device to which the interface is associated (live link to the Device Viewer).
- Interface: The switched port identifier (live link to the Interface Viewer, displays the History of the port).
- VRF Name: The name of the VRF instance.
- Interface Description: Functional description of the LAN switched port type.
- Interface Type: The standard interface type supported by the port. For switched Ethernet, this value will typically be ethernet-csmacd.
- Interface MAC: The 48-bit hardware address for each port in the Link Changes list (live link to the Interface Viewer, displays the history of the port).
- Trunk Status: The switched interface's trunk status.
- If Oper Status: The switched interface's operating status.
- If Admin Status: The switched interface's Admin status (whether the port is administratively enabled by the operator).
- Speed: The line speed of each listed interface.
- #End Hosts, The number of detected End Hosts bound to each listed interface, if any (live link to the End Hosts Present page).
Pay special attention to the # End Hosts column. As with any data column, you can sort by this value, upwards or downwards. Choosing Sort Descending brings all switch interfaces with connected hosts to the top of the table, with the interfaces having the highest number of connected hosts at the top. For any switched interface, clicking the numeric hyperlink in the # End Hosts column will close the Ports Present table and display the End Hosts Present table listing only the end hosts associated with the specific interface. You can readily identify each connected host by their respective host names, host IP address, VLAN name and other information.
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Note: In many cases, the collection of end hosts for each located hub are clients bound to a VLAN.
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- Action icon: provides the Action menu with View Device History, Set Admin Status, Edit Description and Topology Viewer options.
- Device Name: The Ethernet switching device to which the interface is associated (live link to the Device Viewer, displaying the Issues page).
- Interface: The switched port identifier (live link to the Interface Viewer, displays the History of the port).
- Interface Type: The standard interface type supported by the port. For switched Ethernet, this value will typically be ethernet-csmacd.
- Interface MAC: The 48-bit hardware address for each port in the Link Changes list (live link to the Interface Viewer, displays the History of the port).
- If Oper Status: the switched interface's operating status.
- If Admin Status: the switch port's Admin status (if the port is administratively enabled by the operator).
- # End Hosts: The number of detected End Hosts bound to the hub interface (live link to the End Hosts Present page). The Hub Locator table is sorted in descending order by this column.
- First Seen: The timestamp indicating when Switch Port Management first polled the device.
- Last Seen: The timestamp indicating the last occasion when Switch Port Management detected the device on the network.
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The Refine View tool is helpful for tracing the path of a L3 switched VLAN.
Every device in a Device Group that participates in the same switched VLAN can be marked using this feature. To perform any VLAN path trace, click on Network Explorer –> Topology –> Network accordion menu –> Aggregate and click the Refine View button.
The Edit View dialog appears, displaying the Device Group tab.
Hover the mouse over the Action icon for the VLAN ID that you want to use as the basis for your VLAN path trace. Choose Select Blue or Select Yellow from the Actions pop-up menu. The color for the VLAN ID appears under the Selections column. Click OK, and the Topology map redraws to add color markers to all devices in the map corresponding to the chosen VLAN ID.
You can hover the mouse over the devices carrying the VLAN, and over the links between devices to get more information about each link.
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In the Switch Port Management page, the End Devices category displays all end host devices associated with LAN switches in the selected device group, and filters them into several functional categories.
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Note: To optimally configure Switch Port Management for end host detection, ensure that all end host subnetworks that you want managed are included in NetMRI's Discovery IP ranges. The discovered end hosts also must be excluded from management by NetMRI. This can be done by specifying the IP ranges for the end host network segments in Step 2 of the Setup Wizard or by opening Settings icon –> Setup –> Discovery Settings following initial NetMRI setup. Also see the Configuring Discovery Ranges topic for more information.
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Also see Using the Interface Viewer for more information on how to use the Interface Viewer feature set.
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Note: In earlier releases, NetMRI did not detect and report neighbor relationships between switch trunk ports and non-trunked downstream switch ports. This could present issues for discovery and inventory of ESXi and Hyper-V VM host servers and any other end host neighbors of trunk ports. In Release 6.9 onwards, when NetMRI detects no switch downstream from those trunk ports, the system correctly reports all end host neighbors of switched trunk ports in Network Explorer End Host and Connected End Host tables, Device Viewer/Interface Viewer neighbor tables and in the Topology feature.
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Virtual Machines acting as De Facto end hosts in the network, including VMs that directly communicate through a switch port, and VMs communicating through a 'virtual switch,' which in turn communicates through a switch port, will not appear in End Host-related tables and pages. NetMRI will discover such VMs but they are not visible in End Hosts tables. Virtual switches are also not supported by NetMRI. Virtual machine-based hosts appear in the Network Explorer –> Inventory page under Connected End Hosts, but their entries will not show switching infrastructure.
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The VLAN Viewer is a pop-up browser window that provides table rows listing several basic characteristics of a selected virtual LAN interface, including all switches that terminate the VLAN.
Most of the key information about a VLAN appears in the top section of the Viewer, including the Root Bridge, the root bridge priority and ID, and its configured Max Age, Hello Time and Bridge FWD Delay values.
Important table data columns include the Priority field, the Bridge Address, and a Timers field showing the status of spanning tree timers for VLAN switching.
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Note: See Viewing Active VLANs and VLAN Configuration for more details about VLAN settings displayed in the Device Viewer and the VLAN Viewer.
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Switch Port Management provides for a set period of days after an SPM port is free and unused before it is specifically defined as Available. When a port is first disconnected from all other devices, it is in a Down link state, and appears in the Free category. After a certain time period elapses (the duration of which is based on the business policies of the IT department), the port is counted against the Available category and removed from the Free category, because its link state has been down for longer than the specified time period.
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Note: For Switch Port Management, the default transition time between an SPM port's Free status and its change to Available is 14 days.
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The ARP Cache Refresh Period defines the time period between ARP refreshes by NetMRI across all switch ports. Before any other switchport polling operations take place (including device group or global polling operations initiated by the NetMRI user), another ARP refresh is carried out by the appliance regardless of the time interval. To modify advanced SPM settings, do the following:
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For the Free to Available Ports value, the new setting is reflected as the hyperlink in the Available Ports and Available Ports % counters in the Capacity Summary– Summary – Ports pane under Switch Port Management.
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NetMRI uses ARP cache refresh to control LAN switches from which switch-forwarding data is collected.
When ARP cache refresh is enabled for a LAN switch, before further collection of switch-forwarding data, NetMRI pings all known IP addresses known to exist as members of the device's switch-forwarding table, by relating previously gathered switch-forwarding data MAC addresses to determine their IP addresses. Because this requires a prior SPM poll, the first poll of any switch by SPM after the device is added to the license will not perform an ARP cache refresh.
For subsequent polling events, NetMRI performs ARP cache refresh by sending a UDP packet on Port 80 to each IP address in the switch's forwarding table, without waiting for return messages. This has the effect of re-populating the switches' forwarding table. NetMRI sends nothing to the switches themselves, the refresh is performed against all the end hosts and other devices connected to each LAN or distribution switch.
The appliance also tracks the time period required to collect switch-forwarding data and compare the result to the last ARP refresh. Once a timeout period is exceeded, NetMRI will re-perform the refresh on the switch, and repeat as necessary as data is collected from the device.
The appliance automatically performs an ARP cache refresh immediately before a new switch port polling session.