What does CDP mean in networking?

Cisco Discovery Protocol
Cisco Discovery Protocol (CDP) is a proprietary Data Link Layer protocol developed by Cisco Systems in 1994 by Keith McCloghrie and Dino Farinacci. It is used to share information about other directly connected Cisco equipment, such as the operating system version and IP address.

What are three features of CDP?

CDP runs over the data link layer only. Therefore, two systems that support different network-layer protocols can learn about each other. Mismatched Port-duplex states between connected devices….Information.

How does Cisco CDP work?

When a Cisco device boots up, CDP starts up by default. CDP automatically discovers neighboring Cisco devices running CDP, regardless of which protocol or suites are running. CDP exchanges hardware and software device information with its directly connected devices. CDP message is sent every 60 seconds on interfaces.

What is CDP in switch?

CDP is a device discovery protocol that runs over Layer 2 (the data link layer) on all Cisco-manufactured devices (routers, bridges, access servers, and switches) and allows network management applications to discover Cisco devices that are neighbors of already known devices.

Should I disable CDP?

By default, most people leave CDP running. CDP contains juicy information regarding hostname, management IP, local and remote interfaces, IOS version, platform and VTP domain. However, unless the device has all interfaces facing the Internet, there is no real need to disable CDP across the entire platform.

Is CDP enabled by default?

After CDP is running on your device, by default, CDP is enabled on all interfaces of the device. At times, you may want to disable CDP — for example, on the external interface of the Internet router connected to your ISP because the ISP does not need the details about the internal network configuration.

What layer of OSI is CDP?

Layer 2
Cisco Discovery Protocol (CDP) is a Layer 2 OSI model Cisco proprietary protocol used to find a Cisco neighbor device and learn about the type of hardware, software version, and active interfaces.

What is LLDP and CDP?

LLDP (Link Layer Discovery Protocol) and CDP (Cisco Discovery Protocol) are link layer protocols for directly-connected LLDP and CDP-capable neighbors to advertise themselves and their capabilities. CDP/LLDP can be enabled or disabled globally or per port.

Should I turn on IGMP snooping?

IGMP snooping is an important feature of network switches. When it is enabled, the bandwidth consumption will be reduced in a multi-access LAN environment so as to avoid flooding the entire VLAN, and network information security can also be improved at the same time.

Is IGMP snooping required for multicast?

In order for IGMP, and thus IGMP snooping, to function, a multicast router must exist on the network and generate IGMP queries. Without a querier IGMP membership reporting may be incomplete and the tables associating member ports and multicast groups are potentially incomplete and snooping will not work reliably.

How are multicast packets distributed in a network?

Where broadcast packets are received by all receivers in a particular network segment (or broadcast domain), multicast packets are received only by receivers that want them. Also, multicast receivers can be distributed throughout a larger network behind routers.

Which is an example of a multicast address?

Multicast frames have a value of 1 in the least-significant bit of the first octet of the destination address. This helps a network switch to distinguish between unicast and multicast addresses. One example of an Ethernet multicast address would be 01:00:0C:CC:CC:CC, which is the address used by CDP (Cisco Discovery Protocol).

What kind of media does CDP run on?

CDP runs on all media that support Subnetwork Access Protocol (SNAP), including local-area network (LAN), Frame Relay, and Asynchronous Transfer Mode (ATM) physical media. CDP runs over the data link layer only.

Where do Cisco devices send CDP announcements to?

Cisco devices send CDP announcements to the multicast destination address 01-00-0c-cc-cc-cc, out each connected network interface. These multicast frames may be received by Cisco switches and other networking devices that support CDP into their connected network interface.