does link layer topology need discovery

Drawing a full network maps requires that Link-Layer Topology Discovery (LLTD) is enabled on the requesting PC, and that the responder is enabled on all responding PCs. Windows Vista and Windows 7 provide the related elements by default. There is a hotfix to enable the feature in Windows XP SP3.

Full Answer

How can you discover network topology?

• Start with a device scan. ...
• Give more details. ...
• Discover the network with one or a combination of the following methods, ARP, SNMP, SSH, PING, and LLDP.
• Document and create an inventory of the results, including devices and their connectivities.
• The network map and inventory can help you visualize the entire topology. ...
• Run more discoveries. ...

What is the best network topology?

Which is the Best Network Topology?

• Scalability. While choosing a network topology, consider network scalability. ...
• Cable type. As explained above, nodes within a network are connected using coaxial, fiber-optic, or twisted-pair cables.
• Cable length. More cables mean more complexity. ...
• Cost. Budget is one of the most important factors when you want to install a network topology. ...

What are the types of network topology?

Types of Network Topology: Bus, Ring, Star, Mesh, Tree Diagram

• Types of Networking Topologies. Logical topology gives insight’s about network’s physical design.
• Point to Point (P2P) Point-to-point topology is the easiest of all the network topologies. ...
• Bus Topology. ...
• Ring Topology. ...
• Star Topology. ...
• Mesh Topology. ...
• Tree Topology. ...
• Hybrid Topology. ...
• Summary. ...

What is network and network topology?

• Network Topology is the manner in which nodes/devices and links are arranged in a network.
• Types of network topologies are – Bus Topology, Ring Topology, Star Topology, Mesh Topology, Tree Topology.
• Every topology has some strengths and weaknesses. ...

More items...

Can I disable Link Layer Topology Discovery?

Individual users with administrative rights may also disable the ability to map their computers, regardless of Network profile, by merely disabling the Link-Layer Topology Discovery Responder. You may change the default behavior through local (as well as site, domain, or OU based Group Policy).

What is Link Layer Topology Discovery Responder?

The Link-Layer Topology Discovery (LLTD) is a component of the Windows networking implementation that allows computers and other devices to be represented on a map. Windows Vista, Windows Server 2008, and Windows 7 computers can natively populate the Network Map.

What is Microsoft Link Layer Discovery Protocol?

The LLTD protocol enables applications to quickly discover devices at the data-link layer, and it enables a central, graphical view of everything that is connected to the network.

What is the purpose of Lldp?

LLDP enables Ethernet network devices, such as switches and routers, to transmit and/or receive descriptive information, and to store such information learned about other devices. The data sent and received by LLDP is useful for many reasons: ∎ devices can discover neighbors—other devices directly connected to it.

How do I enable mapping on my domain?

Enable Network Mapping on Domain and Public NetworksOpen gpedit. ... Navigate to Computer Configuration\Administrative Templates\Network\Link-Layer Topology Discovery.Double-click the Turn On Mapper I/O (LLTDIO) Driver policy, select Enabled, and then select Allow Operation While In Domain.More items...•

What is Microsoft network Client?

The "Client for Microsoft Networks" is the basic component of Windows networking. It allows a computer to access resources on a Microsoft network, and is installed by default. If your computer is connected to your cable modem by Ethernet, you need to leave this item checked.

Is LLDP needed?

You might need LLDP , which is the standardized equivalent of CDP, when you need interoperability btwn non-Cisco boxes and also when you have IP-Phones connected to to access switches. Newer Ip-Phones use LLDP-MED. LLDP, like CDP is a discovery protocol used by devices to identify themselves.

How do I enable LLDP?

To enable LLDP on the device, use “lldp run” on the global configuration mode. Again, “no lldp run” is used to disable lldp on that device. To specify the TLVs on the device, use “lldp med-tlv-select tlv” command. Here, tlv can be inventory-management, power-management, network-policy, location etc.

Is LLDP a security risk?

LLDP is used mainly to identify neighbors in the network so that security risks can be exposed.

Can I disable LLDP?

Disabling and Enabling LLDP on an interface Enter global configuration mode. Issue interface interface-id command. This will specify the interface on which you are disabling LLDP. Issue no lldp transmit or no lldp receive.

Is LLDP enabled by default on Cisco?

LLDP is enabled by default on all supported interfaces to send and to receive LLDP information. If the interface is configured as a tunnel port, LLDP is automatically disabled. Beginning in privileged EXEC mode, follow these steps to disable LLDP on an interface. configure terminal Enter global configuration mode.

What is the difference between LLDP and CDP?

LLDP is a layer two discovery protocol, similar to Cisco's CDP. The big difference between the two is that LLDP is a standard while CDP is a Cisco proprietary protocol. Cisco devices support the IEEE 802.1ab version of LLDP. This allows non-Cisco devices to advertise information about themselves to our network devices.

What is LLDP snooping?

BTI7800 transport interfaces configured for Ethernet (10ge and 100ge) can be provisioned to snoop Link Layer Discovery Protocol (LLDP) frames to gather information about attached equipment.

Does LLDP use multicast?

LLDP frames use the IEEE 802.3 format, which consists of the following fields: • Destination address (6 bytes)—Uses a multicast address of 01-80-C2-00-00-0E.

What is LLDP multicast?

LLDP Multicast address is 01-80-C2-00-00-0E. LLDP provides support for a set of attributes used to discover neighbor devices. These attributes are referred to as TLVs, which contain type, length, and value descriptions.

What is LLTD in networking?

Link Layer Topology Discovery (LLTD) is a proprietary link layer protocol for network topology discovery and quality of service diagnostics. Microsoft developed it as part of the Windows Rally set of technologies. The LLTD protocol operates over both wired (such as Ethernet (IEEE 802.3) or power line communication) as well as wireless networks (such as IEEE 802.11 ).

What is LLTD in Windows Vista?

Link Layer Topology Discovery in Windows Vista consists of two components. The LLTD Mapper I/O component is the master module which controls the discovery process and generates the Network Map. Appropriate permissions for this may be configured with Group Policy settings. It can be allowed or disallowed for domains, and private and public networks. The Mapper sends discovery command packets onto the local network segment via a raw network interface socket. The second component of LLTD are the LLTD Responders which answer Mapper requests about their host and possibly other discovered network information.

Which end is similar to LLTD?

Cisco Discovery Protocol - Similar end as LLTD which is based on CDP.

Does Windows XP have LLTD?

Windows XP does not contain the LLTD protocol as a standard component and as a result, Windows XP computers do not appear on the Network Map unless the LLTD responder is installed on Windows XP computers. LLTD is available for download for 32-bit editions of Windows XP with Service Pack 2 (as a publicly released update) ...

Does LLTD responder work on IPv6?

The LLTD responder for Windows XP only supports reporting of IPv4 addresses and not IPv 6.

What is device location discovery?

Device location discovery to allow creation of location databases and, in the case of Voice over Internet Protocol (VoIP), Enhanced 911 services.

Where is LLDP stored?

Information gathered with LLDP can be stored in the device management information base (MIB) and queried with the Simple Network Management Protocol (SNMP) as specified in RFC 2922. The topology of an LLDP-enabled network can be discovered by crawling the hosts and querying this database. Information that may be retrieved include:

What is LLDP in networking?

The Link Layer Discovery Protocol ( LLDP) is a vendor-neutral link layer protocol used by network devices for advertising their identity, capabilities, and neighbors on a local area network based on IEEE 802 technology, principally wired Ethernet. The protocol is formally referred to by the IEEE as Station and Media Access Control Connectivity Discovery specified in IEEE 802.1AB with additional support in IEEE 802.3 section 6 clause 79.

How is LLDP information sent?

LLDP information is sent by devices from each of their interfaces at a fixed interval, in the form of an Ethernet frame. Each frame contains one LLDP Data Unit (LLDPDU). Each LLDPDU is a sequence of type-length-value (TLV) structures.

hazelnut

Firstly saurabhdua we don't allow direct downloads of things like installers or a pdf to be posted on forum. I'm sure you understand why.

Andavari

Messing around in the Network in my opinion requires making a System Restore Point beforehand, even for people who think they know what they're doing.

saurabhdua

I were expecting the Volunteers out there on this Forum to be BOLD in their approach, & will never wary to try & suggest something New! :-)

saurabhdua

So Mta...That affirms the point that Most of these entries are of No Use to a Normal Web surfer. Enough of Sharing takes place through "Facebook" & "Twitter"; & similarly, My ISP is there to throttle down the Bandwidth limits after a certain allocation.....Then Why CHOKE my own neck by enabling "QoS Packet Scheduler"!? :-)

streetskater

This is a little old, but saurabhdua, I want to re-enforce the "rightness" of your "natural" inclination to want to CLEAN UP the mess Redmond has been creating for LOW these last nearly 40 years. I'm not questioning the advice here to be circumspect with delving in where you're not sure what the consequence will be.

What is link layer topology?

The Link-Layer Topology Discovery Mapper (lltdsvc) service creates a network map, which includes computer and device connectivity information and metadata that describes each computer and device. If this service is disabled, the network map does not function properly.

What is the default startup type for Link-Layer Topology Discovery Mapper?

This service is installed by default and its startup type is Manual. When the Link-Layer Topology Discovery Mapper service is started in its default configuration, it logs on by using the Local Service account.

What is LLTD in network maps?

Drawing a full network maps requires that Link-Layer Topology Discovery (LLTD) is enabled on the requesting PC, and that the responder is enabled on all responding PCs. Windows Vista and Windows 7 provide the related elements by default. There is a hotfix to enable the feature in Windows XP SP3.

How to see network map in Windows 7?

One of my favorite Windows 7 tools is the ability to display an entire network map by navigating to the Network and Sharing Center in the Control Panel and clicking “See Full Map”. The tool provides an excellent means to view either ad hoc or infrastructure network elements.

What is an unknown NIC driver?

In some cases an unknown NIC driver or secondary NIC devices may be identified as an ‘Unidentified Network’ . This most commonly occurs when a device contains both a wired and wireless NIC. If both are enabled simultaneously after one has been configured, the second may show up as Unidentified or Public. In some cases, the Network and Sharing Center interface will not allow a change to the Network profile classification. Without a Network profile or with a Public profile, LLTD is likely to be blocked by security, firewall, or group policy settings.

Do NICs interfere with link layer topology?

In some instances, NICs support their own configuration management features that will interfere with Link Layer Topology. For instance, NVIDIA Ethernet drivers will need VLAN capabilities disabled.

Can you add network maps to troubleshooting tools?

With just a little effort, you should be able to add Network Maps to your arsenal of troubleshooting tools.

Is link layer topology still enabled?

While Link-Layer Topology Discovery is still enabled within the Network stack for Windows 8, the ability to draw full network maps has been removed from the Network and Sharing Center. Microsoft suggests using Network discovery and looking for Network computers via Windows explorer. It does not appear that the feature will become available in Windows 8.

Overview

Link Layer Topology Discovery (LLTD) is a proprietary link layer protocol for network topology discovery and quality of service diagnostics. Microsoft developed it as part of the Windows Rally set of technologies. The LLTD protocol operates over both wired (such as Ethernet (IEEE 802.3) or power line communication ) as well as wireless networks (such as IEEE 802.11).
LLTD is included in Windows 7, Windows Vista and Windows 10. It is used by their Network Map f…

Information gathered

Applications

Notes

The Link Layer Discovery Protocol (LLDP) is a vendor-neutral link layer protocol used by network devices for advertising their identity, capabilities, and neighbors on a local area network based on IEEE 802 technology, principally wired Ethernet. The protocol is formally referred to by the IEEE as Station and Media Access Control Connectivity Discovery specified in IEEE 802.1AB with additional support in IEEE 802.3 section 6 clause 79.

External links