== Setup ==
==== What is the difference between the Monitor interfaces and the Management interfaces? ====

The Monitor interfaces are used to passively analyze traffic and cannot be used for management functions such as accessing
the user interface. These interfaces do not generate any traffic apart from forwarding traffic received on the adjacent
interface if configured to Bridge mode.
The Management interface on the other hand, is dedicated for management functions like accessing the user interface,
downloading and uploading pcaps, streaming captured data to the device for analysis and so on. The Management
interface actively participates in the network it is connected to.

==== How can I monitor the traffic of a single computer? ====

The easiest way of monitoring and analyzing the traffic of a single device like a computer is to configure the
Allegro Network Multimeter in Bridge mode. The device to be monitored is connected to one interface of a bridged pair
of interfaces on the Allegro Network Multimeter. The other interface of the bridged pair is connected to the
network to which the device would normally be directly connected.

In a setup like this, the Allegro Network Multimeter transparently forwards traffic between the device and the
network while providing full insight into the traffic between the device and the network.

==== What is the difference between Bridge mode and Sink mode? ====

If the Allegro Network Multimeter is configured to Sink mode, all Monitor interfaces act in a similar way in that they
receive traffic which is then analyzed by the appliance but not forwarded. The appliance acts as a traffic
sink, as it receives packets, analyzes them and discards them. This mode is ideally suited for situations
where traffic is already a copy; for example, on a Mirror Port of a Switch or on a network traffic Tap.

If configured in Bridge mode, the Allegro Network Multimeter transparently forwards all traffic between adjacent Monitor
interfaces while simultaneously analyzing the forwarded traffic. The appliance acts as a network Bridge and can
be connected between two network devices which would normally be connected directly to each other. This mode
is suited for inserting the Allegro Network Multimeter directly into a point of the network without the need of a separate network
Tap or other means of providing a copy of the network traffic.

==== I have used the LAN Management interface but I do not know the leased IP. How can I get the assigned IP address? ====

===== DHCP server =====

If the selected DHCP server provides some kind of log output or an overview of devices for which IP address leases have
been granted, it might help to search for a device with a hostname that starts with '''allegro-mm-''' followed by a four
digit hexadecimal number. The Allegro Network Multimeter announces itself with this hostname when it requests a
DHCP lease and should be traceable in the DHCP server info.

===== WI-FI =====

Every Allegro Network Multimeter comes with an USB to Wi-Fi adapter. In the factory default configuration the adapter will
create a wi-Fi Access Point when connected to the appliance. This Access Point shows up as '''allegro-mm-xxxx''' where the
'''xxxx''' part consists of a hexadecimal number which is unique to the device. In factory default settings the password
for the Wi-Fi network is '''Allegro-MM''' (without the quotes). As soon as there is a connection to Wi-Fi, the user
interface of the device can be accessed by either browsing to https://allegro or https://192.168.4.1.
When access to the user interface is established, the IP address of the LAN Management interface can be found under
'''Settings''' -> '''Management interface settings''' in the '''Active interfaces''' section.

===== Display =====

The Allegro Network Multimeter 200 comes with a HDMI connector and
the 1000 and 3000 series come with a VGA connector. When a compatible
display is connected, the console displays information about the running
Firmware version along with information on the configured
management network IP addresses. On the 200 model the
display must be connected before starting the appliance to obtain the output.

===== KVM =====

The video output of the device displaying the management IP addresses can be viewed over the network using the [[IPMI KVM on Allegro series 1000+|KVM/IPMI management module of the 1000 or 3000 series]]. Please see the FAQ entry '''What can I do with the integrated KVM port?''' on how to get started.

==== What can I do with the integrated KVM port? ====

The Allegro Network Multimeter 1000 and 3000 series devices contain a KVM/IPMI management module from Supermicro by
which several hardware management functions like powering the device on and off, system health messages and much
more can be accessed. It is also possible to view the video output of the device over the network from which the
current active management IP addresses can be retrieved.

By default the KVM/IPMI management module will obtain an IP address through DHCP and the default user name as well
as default password is '''ADMIN''' (without the quotes).

See [[IPMI KVM on Allegro series 1000+]] for additional information.

==== I do not have a Wi-Fi client and I do not have a DHCP server. How can I access the Allegro Network Multimeter? ====

It is possible to make the Allegro Network Multimeter set a temporary static address on the LAN management interface.
It will return to the configured behaviour for the LAN management interface following the next restart.

To enable the temporary static IP address, a USB keyboard is needed. When the keyboard is attached to one of the USB
ports of the Allegro, start the device. Wait for two minutes to make sure that the device is fully operational.
Then press and hold the '''shift''' key while pressing the '''s''' key. After this procedure the device will be configured to
use the IP address '''192.168.0.1''' on the LAN management interface. It is now possible to e.g. connect another
computer to the LAN management interface with an IP address statically configured to e.g. '''192.168.0.100''' and from
that computer the user interface of the Allegro is accessible at https://192.168.0.1.
If for some reason the IP address '''192.168.0.1''' is already used in the network, the Allegro will try to
set another IP address in the range of '''192.168.0.2''' - '''192.168.0.10'''.

Once access to the user interface is established, a static IP address can be configured under '''Settings''' ->
'''Management interface settings'''.

== Data protection ==

==== What kind of user data is stored on the Allegro Network Multimeter ====

All metadata and statistics are stored in the device's main memory and are deleted as soon as the device is rebooted,
powered off, or packet processing is restarted. Any user data that can be derived from these statistics is therefore
only stored for the duration of continuous operation. If, however, reports are generated and stored on the device, these
reports exist until manually deleted or until a device configuration reset is performed.

Raw packet data in the packet ring buffer or in stored pcap capture files will persist on the internal or external
storage until overwritten or deleted. If it is important that captured or deleted data must not be retrieved by someone
with physical access to the storage devices, it is possible to format the storage device with industry-standard full
disk encryption.

==== How can I reset the Allegro Network Multimeter to a default configuration? ====

There are two ways to reset the configuration of the appliance.

The first option is to use the '''Reset System Configuration''' button which can be found under '''Settings''' ->
'''Administration''' in the user interface. After confirmation, this will trigger a restart of the system and afterward the
appliance will revert to the factory default settings.

If, for some reason, the user interface is not accessible, a configuration reset can be performed by attaching
a USB keyboard and a HDMI/VGA display to the appliance. When booting the device, there is a short period when a GNU GRUB
menu is displayed. The arrow up and arrow down keys can be used to select an entry and the selected entry can be chosen
by pressing the '''enter''' key. Below the default '''multimeter''' entry, there is a '''configuration-reset''' option which will
perform a reset to default configuration and then reboot the appliance.

Keep in mind that a reset to the default configuration does not delete any
packet ring buffer data or captured files from internal or external
storage.

== System behavior ==

==== Where does the Allegro Network Multimeter display L1 issues like bad CRC frames? ====

Issues like these are accounted for the Monitoring interface on which the issue was encountered and the respective
statistics are available on the '''Interface stats''' page in the '''Errors''' column. For an explanation of the error
counters, please refer to the [[Interface_statistics|Interface statistics]] manual page.

==== What happens in case of a system overload? ====

In case of a system overload, a prominent warning is displayed at the top of the user interface for a few seconds
and these warnings and the time when the error occurred can be reviewed on the '''Info''' -> '''Status''' page. As long as there are
still notifications on the '''Info''' -> '''Status''' page, this is indicated by colored icons at the top of the user interface.

If a system overload occurs and not all packets can be analyzed, these packets are accounted at the Monitoring
interface on which they were received. The counter can be found on the '''Interface stats''' page in the '''Errors''' column
under the '''Not processed''' section and is titled '''due to overload'''.

When the Allegro Network Multimeter is operating in bridge mode and packets cannot be processed due to a system
overload, a software bypass will ensure that these packets are still forwarded to the adjacent Monitoring interface.

==== What happens if the maximum number of stored connections has been reached? ====

In this case, the Allegro Network Multimeter will start freeing up memory by removing historic statistical data which
lies before a certain point in time. This cutoff time is constantly adjusted to provide the best possible use of the
available memory. For how far back-in-time historical statistics are currently available, can be reviewed on the
'''Info''' -> '''System Info''' page.

==== I can only see the traffic of the last day. How can I increase this period? ====

If the system does not provide a sufficient look back-in-time with the given traffic, it may help to deactivate certain
features that provide very detailed information but also consume a large amount of memory. Features that typically
fit into this category are the different settings of the '''IP statistics'''. These settings can be accessed by navigating to
'''IP''' -> '''IP Statistics''' and clicking the '''Settings''' button at the top of the page. Especially turning off the
'''Store connection information for every IP''' and '''Store traffic history graph for IP peers''' settings can help saving
a lot of memory.

==== What happens to the data after shutdown, reboot, or restart processing? ====

The Allegro Network Multimeter uses an In-Memory database to store the
metadata of the packets it processes. This metadata will be lost when the
processing is stopped (shutdown, reboot, restart processing). This metadata
is also lost in case of an unexpected power loss.

When using a packet ring buffer (see [[Storage|storage]]), the packets will be
stored on the attached hard disk drive. This data is not lost after the
processing is stopped. It is possible to reanalyze the packet ringbuffer, but
this will interrupt the '''live''' mode, so no new packets will be processed.

== Allegro hardware ==

==== What types of SFP modules are supported? ====

See [[List_of_Supported_Transceiver_Modules|List of supported transceiver modules]] for details.

== Bypass ==

==== What bypass options are available? ====

Two bypass options are available:

* a quad-port RJ45 1Gbps copper option supporting 1000BaseT and 100BaseT speeds. Each pair of interfaces makes up a bridged link with bypass.
* a dual-port 10Gbps fiber option with builtin SR transceivers and LC connectors. The two interfaces make up a bridged link with bypass.

==== How does the bypass work? ====

If the Allegro Network Multimeter contains a bypass option, it is only active when the device is configured to operate
in bridge mode. The bypass activates when the device is powered off, when the device is starting but is not yet
processing traffic or when an unexpected failure like a crash or a power loss occurs. If the bypass is active, the
two interfaces that make up a bypass link will be physically connected to each other so that devices connected on
either side will always find a working link.

If the device is operating in sink mode, the bypass interfaces will act just like all the other interfaces on the device
and the bypass will never be activated.

== User interface ==

==== What does the question mark on packets/bytes counters mean? ====

The Allegro Network Multimeter stores historical traffic data in
different time resolutions depending on the age of the data.

When zooming into a specific time window, packet and byte counters are
shown for this specific time interval only. Since the time resolution
available internally might be coarser than the selected zoom level,
the shown packet and byte values might not exactly represent the time
interval.

If this is the case, the actual interval time is shown in square
brackets (for example [120s]). This means that the value represents
the time between the end of the selected interval (the right end of
the graph) and the shown number of seconds in the past.

This value is shown to avoid confusion about unexpected values due to
interactive graph zooming.

==== How can I print statistics? ====

The Allegro Network Multimeter web interface can be printed by using
the built-in printing support of your browser. Just navigate to the desired
statistics and click on the printing button (Ctrl+P in most browsers). The pages
are optimized for printing. Tabs, PCAP and navigation buttons are hidden in
print mode.

If the browser is truncating the page in print preview, you can try to use
'''Shrink to fit''' option (Firefox) or use a smaller scaling than 100% (Chrome).
You can also use another page orientation and change between '''landscape''' or '''portrait'''.

== Packet ring buffer ==

==== Which time stamps are used during packet ring buffer replay? ====

Packet ring buffer replay will use the original time stamps of the packets as they were captured. Therefore the replay
recreates the original sequence and timing of packets in the displayed statistics.

== Capturing ==

==== How many captures can be used in parallel? ====

The Allegro Network Multimeter 200 supports up to 3 parallel and the
1000/3000 model supports up to 4 parallel captures. If the memory
usage is too high, the number of parallel captures might be lower.

FAQ

2020-05-14T13:04:43Z

David.Griffiths: /* What kind of user data is stored on the Allegro Network Multimeter */

== Setup ==
==== What is the difference between the Monitor interfaces and the Management interfaces? ====

The Monitor interfaces are used to passively analyze traffic and cannot be used for management functions such as accessing
the user interface. These interfaces do not generate any traffic apart from forwarding traffic received on the adjacent
interface if configured to Bridge mode.
The Management interface on the other hand, is dedicated for management functions like accessing the user interface,
downloading and uploading pcaps, streaming captured data to the device for analysis and so on. The Management
interface actively participates in the network it is connected to.

==== How can I monitor the traffic of a single computer? ====

The easiest way of monitoring and analyzing the traffic of a single device like a computer is to configure the
Allegro Network Multimeter in Bridge mode. The device to be monitored is connected to one interface of a bridged pair
of interfaces on the Allegro Network Multimeter. The other interface of the bridged pair is connected to the
network to which the device would normally be directly connected.

In a setup like this, the Allegro Network Multimeter transparently forwards traffic between the device and the
network while providing full insight into the traffic between the device and the network.

==== What is the difference between Bridge mode and Sink mode? ====

If the Allegro Network Multimeter is configured to Sink mode, all Monitor interfaces act in a similar way in that they
receive traffic which is then analyzed by the appliance but not forwarded. The appliance acts as a traffic
sink, as it receives packets, analyzes them and discards them. This mode is ideally suited for situations
where traffic is already a copy; for example, on a Mirror Port of a Switch or on a network traffic Tap.

If configured in Bridge mode, the Allegro Network Multimeter transparently forwards all traffic between adjacent Monitor
interfaces while simultaneously analyzing the forwarded traffic. The appliance acts as a network Bridge and can
be connected between two network devices which would normally be connected directly to each other. This mode
is suited for inserting the Allegro Network Multimeter directly into a point of the network without the need of a separate network
Tap or other means of providing a copy of the network traffic.

==== I have used the LAN Management interface but I do not know the leased IP. How can I get the assigned IP address? ====

===== DHCP server =====

If the selected DHCP server provides some kind of log output or an overview of devices for which IP address leases have
been granted, it might help to search for a device with a hostname that starts with '''allegro-mm-''' followed by a four
digit hexadecimal number. The Allegro Network Multimeter announces itself with this hostname when it requests a
DHCP lease and should be traceable in the DHCP server info.

===== WI-FI =====

Every Allegro Network Multimeter comes with an USB to Wi-Fi adapter. In the factory default configuration the adapter will
create a wi-Fi Access Point when connected to the appliance. This Access Point shows up as '''allegro-mm-xxxx''' where the
'''xxxx''' part consists of a hexadecimal number which is unique to the device. In factory default settings the password
for the Wi-Fi network is '''Allegro-MM''' (without the quotes). As soon as there is a connection to Wi-Fi, the user
interface of the device can be accessed by either browsing to https://allegro or https://192.168.4.1.
When access to the user interface is established, the IP address of the LAN Management interface can be found under
'''Settings''' -> '''Management interface settings''' in the '''Active interfaces''' section.

===== Display =====

The Allegro Network Multimeter 200 comes with a HDMI connector and
the 1000 and 3000 series come with a VGA connector. When a compatible
display is connected, the console displays information about the running
Firmware version along with information on the configured
management network IP addresses. On the 200 model the
display must be connected before starting the appliance to obtain the output.

===== KVM =====

The video output of the device displaying the management IP addresses can be viewed over the network using the [[IPMI KVM on Allegro series 1000+|KVM/IPMI management module of the 1000 or 3000 series]]. Please see the FAQ entry '''What can I do with the integrated KVM port?''' on how to get started.

==== What can I do with the integrated KVM port? ====

The Allegro Network Multimeter 1000 and 3000 series devices contain a KVM/IPMI management module from Supermicro by
which several hardware management functions like powering the device on and off, system health messages and much
more can be accessed. It is also possible to view the video output of the device over the network from which the
current active management IP addresses can be retrieved.

By default the KVM/IPMI management module will obtain an IP address through DHCP and the default user name as well
as default password is '''ADMIN''' (without the quotes).

See [[IPMI KVM on Allegro series 1000+]] for additional information.

==== I do not have a Wi-Fi client and I do not have a DHCP server. How can I access the Allegro Network Multimeter? ====

It is possible to make the Allegro Network Multimeter set a temporary static address on the LAN management interface.
It will return to the configured behaviour for the LAN management interface following the next restart.

To enable the temporary static IP address, a USB keyboard is needed. When the keyboard is attached to one of the USB
ports of the Allegro, start the device. Wait for two minutes to make sure that the device is fully operational.
Then press and hold the '''shift''' key while pressing the '''s''' key. After this procedure the device will be configured to
use the IP address '''192.168.0.1''' on the LAN management interface. It is now possible to e.g. connect another
computer to the LAN management interface with an IP address statically configured to e.g. '''192.168.0.100''' and from
that computer the user interface of the Allegro is accessible at https://192.168.0.1.
If for some reason the IP address '''192.168.0.1''' is already used in the network, the Allegro will try to
set another IP address in the range of '''192.168.0.2''' - '''192.168.0.10'''.

Once access to the user interface is established, a static IP address can be configured under '''Settings''' ->
'''Management interface settings'''.

== Data protection ==

==== What kind of user data is stored on the Allegro Network Multimeter ====

All metadata and statistics are stored in the device's main memory and are deleted as soon as the device is rebooted,
powered off, or packet processing is restarted. Any user data that can be derived from these statistics is therefore
only stored for the duration of continuous operation. If, however, reports are generated and stored on the device, these
reports exist until manually deleted or until a device configuration reset is performed.

Raw packet data in the packet ring buffer or in stored pcap capture files will persist on the internal or external
storage until overwritten or deleted. If it is important that captured or deleted data must not be retrieved by someone
with physical access to the storage devices, it is possible to format the storage device with industry-standard full
disk encryption.

==== How can I reset the Allegro Network Multimeter to a default configuration? ====

There are two ways to reset the configuration of the device.

The first option is to use the '''Reset System Configuration''' button which can be found under '''Settings''' ->
'''Administration''' in the user interface. After confirmation, this will trigger a restart of the system and afterwards the
device will be running with factory default settings.

If, for some reason, the user interface is not accessible, a configuration reset can also be performed by attaching
an USB keyboard and a HDMI/VGA display to the device. When booting the device, there is a short period when a GNU GRUB
menu is displayed. The arrow up and arrow down keys can be used to select an entry and the selected entry can be chosen
by pressing the '''enter''' key. Below the default '''multimeter''' entry, there is a '''configuration-reset''' entry which will
perform a reset to default configuration and then reboot the device.

Keep in mind that a reset to default configuration does not delete any
packet ring buffer data or captured files from internal or external
storage.

== System behavior ==

==== Where does the Allegro Network Multimeter display L1 issues like bad CRC frames? ====

Issues like these are accounted for the Monitoring interface on which the issue was encountered and the respective
statistics are available on the '''Interface stats''' page in the '''Errors''' column. For an explanation of the error
counters, please refer to the [[Interface_statistics|Interface statistics]] manual page.

==== What happens in case of a system overload? ====

In case of a system overload, a prominent warning is displayed at the top of the user interface for a few seconds
and these warnings and the time when the error occurred can be reviewed on the '''Info''' -> '''Status''' page. As long as there are
still notifications on the '''Info''' -> '''Status''' page, this is indicated by colored icons at the top of the user interface.

If a system overload occurs and not all packets can be analyzed, these packets are accounted at the Monitoring
interface on which they were received. The counter can be found on the '''Interface stats''' page in the '''Errors''' column
under the '''Not processed''' section and is titled '''due to overload'''.

When the Allegro Network Multimeter is operating in bridge mode and packets cannot be processed due to a system
overload, a software bypass will ensure that these packets are still forwarded to the adjacent Monitoring interface.

==== What happens if the maximum number of stored connections has been reached? ====

In this case, the Allegro Network Multimeter will start freeing up memory by removing historic statistical data which
lies before a certain point in time. This cutoff time is constantly adjusted to provide the best possible use of the
available memory. For how far back-in-time historical statistics are currently available, can be reviewed on the
'''Info''' -> '''System Info''' page.

==== I can only see the traffic of the last day. How can I increase this period? ====

If the system does not provide a sufficient look back-in-time with the given traffic, it may help to deactivate certain
features that provide very detailed information but also consume a large amount of memory. Features that typically
fit into this category are the different settings of the '''IP statistics'''. These settings can be accessed by navigating to
'''IP''' -> '''IP Statistics''' and clicking the '''Settings''' button at the top of the page. Especially turning off the
'''Store connection information for every IP''' and '''Store traffic history graph for IP peers''' settings can help saving
a lot of memory.

==== What happens to the data after shutdown, reboot, or restart processing? ====

The Allegro Network Multimeter uses an In-Memory database to store the
metadata of the packets it processes. This metadata will be lost when the
processing is stopped (shutdown, reboot, restart processing). This metadata
is also lost in case of an unexpected power loss.

When using a packet ring buffer (see [[Storage|storage]]), the packets will be
stored on the attached hard disk drive. This data is not lost after the
processing is stopped. It is possible to reanalyze the packet ringbuffer, but
this will interrupt the '''live''' mode, so no new packets will be processed.

== Allegro hardware ==

==== What types of SFP modules are supported? ====

See [[List_of_Supported_Transceiver_Modules|List of supported transceiver modules]] for details.

== Bypass ==

==== What bypass options are available? ====

Two bypass options are available:

* a quad-port RJ45 1Gbps copper option supporting 1000BaseT and 100BaseT speeds. Each pair of interfaces makes up a bridged link with bypass.
* a dual-port 10Gbps fiber option with builtin SR transceivers and LC connectors. The two interfaces make up a bridged link with bypass.

==== How does the bypass work? ====

If the Allegro Network Multimeter contains a bypass option, it is only active when the device is configured to operate
in bridge mode. The bypass activates when the device is powered off, when the device is starting but is not yet
processing traffic or when an unexpected failure like a crash or a power loss occurs. If the bypass is active, the
two interfaces that make up a bypass link will be physically connected to each other so that devices connected on
either side will always find a working link.

If the device is operating in sink mode, the bypass interfaces will act just like all the other interfaces on the device
and the bypass will never be activated.

== User interface ==

==== What does the question mark on packets/bytes counters mean? ====

The Allegro Network Multimeter stores historical traffic data in
different time resolutions depending on the age of the data.

When zooming into a specific time window, packet and byte counters are
shown for this specific time interval only. Since the time resolution
available internally might be coarser than the selected zoom level,
the shown packet and byte values might not exactly represent the time
interval.

If this is the case, the actual interval time is shown in square
brackets (for example [120s]). This means that the value represents
the time between the end of the selected interval (the right end of
the graph) and the shown number of seconds in the past.

This value is shown to avoid confusion about unexpected values due to
interactive graph zooming.

==== How can I print statistics? ====

The Allegro Network Multimeter web interface can be printed by using
the built-in printing support of your browser. Just navigate to the desired
statistics and click on the printing button (Ctrl+P in most browsers). The pages
are optimized for printing. Tabs, PCAP and navigation buttons are hidden in
print mode.

If the browser is truncating the page in print preview, you can try to use
'''Shrink to fit''' option (Firefox) or use a smaller scaling than 100% (Chrome).
You can also use another page orientation and change between '''landscape''' or '''portrait'''.

== Packet ring buffer ==

==== Which time stamps are used during packet ring buffer replay? ====

Packet ring buffer replay will use the original time stamps of the packets as they were captured. Therefore the replay
recreates the original sequence and timing of packets in the displayed statistics.

== Capturing ==

==== How many captures can be used in parallel? ====

The Allegro Network Multimeter 200 supports up to 3 parallel and the
1000/3000 model supports up to 4 parallel captures. If the memory
usage is too high, the number of parallel captures might be lower.

FAQ

2020-05-14T13:02:49Z

David.Griffiths: /* I do not have a WIFI client and I do not have a DHCP server. How can I access the Allegro Network Multimeter? */

== Setup ==
==== What is the difference between the Monitor interfaces and the Management interfaces? ====

The Monitor interfaces are used to passively analyze traffic and cannot be used for management functions such as accessing
the user interface. These interfaces do not generate any traffic apart from forwarding traffic received on the adjacent
interface if configured to Bridge mode.
The Management interface on the other hand, is dedicated for management functions like accessing the user interface,
downloading and uploading pcaps, streaming captured data to the device for analysis and so on. The Management
interface actively participates in the network it is connected to.

==== How can I monitor the traffic of a single computer? ====

The easiest way of monitoring and analyzing the traffic of a single device like a computer is to configure the
Allegro Network Multimeter in Bridge mode. The device to be monitored is connected to one interface of a bridged pair
of interfaces on the Allegro Network Multimeter. The other interface of the bridged pair is connected to the
network to which the device would normally be directly connected.

In a setup like this, the Allegro Network Multimeter transparently forwards traffic between the device and the
network while providing full insight into the traffic between the device and the network.

==== What is the difference between Bridge mode and Sink mode? ====

If the Allegro Network Multimeter is configured to Sink mode, all Monitor interfaces act in a similar way in that they
receive traffic which is then analyzed by the appliance but not forwarded. The appliance acts as a traffic
sink, as it receives packets, analyzes them and discards them. This mode is ideally suited for situations
where traffic is already a copy; for example, on a Mirror Port of a Switch or on a network traffic Tap.

If configured in Bridge mode, the Allegro Network Multimeter transparently forwards all traffic between adjacent Monitor
interfaces while simultaneously analyzing the forwarded traffic. The appliance acts as a network Bridge and can
be connected between two network devices which would normally be connected directly to each other. This mode
is suited for inserting the Allegro Network Multimeter directly into a point of the network without the need of a separate network
Tap or other means of providing a copy of the network traffic.

==== I have used the LAN Management interface but I do not know the leased IP. How can I get the assigned IP address? ====

===== DHCP server =====

If the selected DHCP server provides some kind of log output or an overview of devices for which IP address leases have
been granted, it might help to search for a device with a hostname that starts with '''allegro-mm-''' followed by a four
digit hexadecimal number. The Allegro Network Multimeter announces itself with this hostname when it requests a
DHCP lease and should be traceable in the DHCP server info.

===== WI-FI =====

Every Allegro Network Multimeter comes with an USB to Wi-Fi adapter. In the factory default configuration the adapter will
create a wi-Fi Access Point when connected to the appliance. This Access Point shows up as '''allegro-mm-xxxx''' where the
'''xxxx''' part consists of a hexadecimal number which is unique to the device. In factory default settings the password
for the Wi-Fi network is '''Allegro-MM''' (without the quotes). As soon as there is a connection to Wi-Fi, the user
interface of the device can be accessed by either browsing to https://allegro or https://192.168.4.1.
When access to the user interface is established, the IP address of the LAN Management interface can be found under
'''Settings''' -> '''Management interface settings''' in the '''Active interfaces''' section.

===== Display =====

The Allegro Network Multimeter 200 comes with a HDMI connector and
the 1000 and 3000 series come with a VGA connector. When a compatible
display is connected, the console displays information about the running
Firmware version along with information on the configured
management network IP addresses. On the 200 model the
display must be connected before starting the appliance to obtain the output.

===== KVM =====

The video output of the device displaying the management IP addresses can be viewed over the network using the [[IPMI KVM on Allegro series 1000+|KVM/IPMI management module of the 1000 or 3000 series]]. Please see the FAQ entry '''What can I do with the integrated KVM port?''' on how to get started.

==== What can I do with the integrated KVM port? ====

The Allegro Network Multimeter 1000 and 3000 series devices contain a KVM/IPMI management module from Supermicro by
which several hardware management functions like powering the device on and off, system health messages and much
more can be accessed. It is also possible to view the video output of the device over the network from which the
current active management IP addresses can be retrieved.

By default the KVM/IPMI management module will obtain an IP address through DHCP and the default user name as well
as default password is '''ADMIN''' (without the quotes).

See [[IPMI KVM on Allegro series 1000+]] for additional information.

==== I do not have a Wi-Fi client and I do not have a DHCP server. How can I access the Allegro Network Multimeter? ====

It is possible to make the Allegro Network Multimeter set a temporary static address on the LAN management interface.
It will return to the configured behaviour for the LAN management interface following the next restart.

To enable the temporary static IP address, a USB keyboard is needed. When the keyboard is attached to one of the USB
ports of the Allegro, start the device. Wait for two minutes to make sure that the device is fully operational.
Then press and hold the '''shift''' key while pressing the '''s''' key. After this procedure the device will be configured to
use the IP address '''192.168.0.1''' on the LAN management interface. It is now possible to e.g. connect another
computer to the LAN management interface with an IP address statically configured to e.g. '''192.168.0.100''' and from
that computer the user interface of the Allegro is accessible at https://192.168.0.1.
If for some reason the IP address '''192.168.0.1''' is already used in the network, the Allegro will try to
set another IP address in the range of '''192.168.0.2''' - '''192.168.0.10'''.

Once access to the user interface is established, a static IP address can be configured under '''Settings''' ->
'''Management interface settings'''.

== Data protection ==

==== What kind of user data is stored on the Allegro Network Multimeter ====

All metadata and statistics are stored in the device's main memory and are gone as soon as the device is rebooted,
powered off or the packet processing is restarted. Any user data that can be derived from these statistics is therefore
only stored for the duration of continuous operation. If, however, reports are generated and stored on the device, these
reports exist until manually deleted or until a device configuration reset is performed.

Raw packet data in the packet ring buffer or in stored PCAP capture files will persist on the internal or external
storage until overwritten or deleted. If it is important that captured or deleted data cannot be retrieved by someone
with physical access to the storage devices, it is possible to format the storage device with industry-standard full
disk encryption.

==== How can I reset the Allegro Network Multimeter to a default configuration? ====

There are two ways to reset the configuration of the device.

The first option is to use the '''Reset System Configuration''' button which can be found under '''Settings''' ->
'''Administration''' in the user interface. After confirmation, this will trigger a restart of the system and afterwards the
device will be running with factory default settings.

If, for some reason, the user interface is not accessible, a configuration reset can also be performed by attaching
an USB keyboard and a HDMI/VGA display to the device. When booting the device, there is a short period when a GNU GRUB
menu is displayed. The arrow up and arrow down keys can be used to select an entry and the selected entry can be chosen
by pressing the '''enter''' key. Below the default '''multimeter''' entry, there is a '''configuration-reset''' entry which will
perform a reset to default configuration and then reboot the device.

Keep in mind that a reset to default configuration does not delete any
packet ring buffer data or captured files from internal or external
storage.

== System behavior ==

==== Where does the Allegro Network Multimeter display L1 issues like bad CRC frames? ====

Issues like these are accounted for the Monitoring interface on which the issue was encountered and the respective
statistics are available on the '''Interface stats''' page in the '''Errors''' column. For an explanation of the error
counters, please refer to the [[Interface_statistics|Interface statistics]] manual page.

==== What happens in case of a system overload? ====

In case of a system overload, a prominent warning is displayed at the top of the user interface for a few seconds
and these warnings and the time when the error occurred can be reviewed on the '''Info''' -> '''Status''' page. As long as there are
still notifications on the '''Info''' -> '''Status''' page, this is indicated by colored icons at the top of the user interface.

If a system overload occurs and not all packets can be analyzed, these packets are accounted at the Monitoring
interface on which they were received. The counter can be found on the '''Interface stats''' page in the '''Errors''' column
under the '''Not processed''' section and is titled '''due to overload'''.

When the Allegro Network Multimeter is operating in bridge mode and packets cannot be processed due to a system
overload, a software bypass will ensure that these packets are still forwarded to the adjacent Monitoring interface.

==== What happens if the maximum number of stored connections has been reached? ====

In this case, the Allegro Network Multimeter will start freeing up memory by removing historic statistical data which
lies before a certain point in time. This cutoff time is constantly adjusted to provide the best possible use of the
available memory. For how far back-in-time historical statistics are currently available, can be reviewed on the
'''Info''' -> '''System Info''' page.

==== I can only see the traffic of the last day. How can I increase this period? ====

If the system does not provide a sufficient look back-in-time with the given traffic, it may help to deactivate certain
features that provide very detailed information but also consume a large amount of memory. Features that typically
fit into this category are the different settings of the '''IP statistics'''. These settings can be accessed by navigating to
'''IP''' -> '''IP Statistics''' and clicking the '''Settings''' button at the top of the page. Especially turning off the
'''Store connection information for every IP''' and '''Store traffic history graph for IP peers''' settings can help saving
a lot of memory.

==== What happens to the data after shutdown, reboot, or restart processing? ====

The Allegro Network Multimeter uses an In-Memory database to store the
metadata of the packets it processes. This metadata will be lost when the
processing is stopped (shutdown, reboot, restart processing). This metadata
is also lost in case of an unexpected power loss.

When using a packet ring buffer (see [[Storage|storage]]), the packets will be
stored on the attached hard disk drive. This data is not lost after the
processing is stopped. It is possible to reanalyze the packet ringbuffer, but
this will interrupt the '''live''' mode, so no new packets will be processed.

== Allegro hardware ==

==== What types of SFP modules are supported? ====

See [[List_of_Supported_Transceiver_Modules|List of supported transceiver modules]] for details.

== Bypass ==

==== What bypass options are available? ====

Two bypass options are available:

* a quad-port RJ45 1Gbps copper option supporting 1000BaseT and 100BaseT speeds. Each pair of interfaces makes up a bridged link with bypass.
* a dual-port 10Gbps fiber option with builtin SR transceivers and LC connectors. The two interfaces make up a bridged link with bypass.

==== How does the bypass work? ====

If the Allegro Network Multimeter contains a bypass option, it is only active when the device is configured to operate
in bridge mode. The bypass activates when the device is powered off, when the device is starting but is not yet
processing traffic or when an unexpected failure like a crash or a power loss occurs. If the bypass is active, the
two interfaces that make up a bypass link will be physically connected to each other so that devices connected on
either side will always find a working link.

If the device is operating in sink mode, the bypass interfaces will act just like all the other interfaces on the device
and the bypass will never be activated.

== User interface ==

==== What does the question mark on packets/bytes counters mean? ====

The Allegro Network Multimeter stores historical traffic data in
different time resolutions depending on the age of the data.

When zooming into a specific time window, packet and byte counters are
shown for this specific time interval only. Since the time resolution
available internally might be coarser than the selected zoom level,
the shown packet and byte values might not exactly represent the time
interval.

If this is the case, the actual interval time is shown in square
brackets (for example [120s]). This means that the value represents
the time between the end of the selected interval (the right end of
the graph) and the shown number of seconds in the past.

This value is shown to avoid confusion about unexpected values due to
interactive graph zooming.

==== How can I print statistics? ====

The Allegro Network Multimeter web interface can be printed by using
the built-in printing support of your browser. Just navigate to the desired
statistics and click on the printing button (Ctrl+P in most browsers). The pages
are optimized for printing. Tabs, PCAP and navigation buttons are hidden in
print mode.

If the browser is truncating the page in print preview, you can try to use
'''Shrink to fit''' option (Firefox) or use a smaller scaling than 100% (Chrome).
You can also use another page orientation and change between '''landscape''' or '''portrait'''.

== Packet ring buffer ==

==== Which time stamps are used during packet ring buffer replay? ====

Packet ring buffer replay will use the original time stamps of the packets as they were captured. Therefore the replay
recreates the original sequence and timing of packets in the displayed statistics.

== Capturing ==

==== How many captures can be used in parallel? ====

The Allegro Network Multimeter 200 supports up to 3 parallel and the
1000/3000 model supports up to 4 parallel captures. If the memory
usage is too high, the number of parallel captures might be lower.