Vtp Feature Support - Cisco Nexus 7000 Series Configuration Manual

VTP Feature Support

You can use CDP to discover and view information about all the Cisco devices that are directly attached to
the device.
CDP gathers protocol addresses of neighboring devices and discovers the platform of those devices. CDP
runs over the data link layer only. Two systems that support different Layer 3 protocols can learn about each
other.
Each device that you configure for CDP sends periodic advertisements to a multicast address. Each device
advertises at least one address at which it can receive SNMP messages. The advertisements also contain
hold-time information, which indicates the length of time that a receiving device should hold CDP information
before removing it. You can configure the advertisement or refresh timer and the hold timer.
CDP Version-2 (CDPv2) allows you to track instances where the native VLAN ID or port duplex states do
not match between connecting devices.
CDP advertises the following type-length-value fields (TLVs):
• Device ID
• Address
• Port ID
• Capabilities
• Version
• Platform
• Native VLAN
• Full/Half Duplex
• MTU
• SysName
• SysObjectID
• Management Address
• Physical Location
• VTP
All CDP packets include a VLAN ID. If you configure CDP on a Layer 2 access port, the CDP packets sent
from that access port include the access port VLAN ID. If you configure CDP on a Layer 2 trunk port, the
CDP packets sent from that trunk port include the lowest configured VLAN ID allowed on that trunk port.
The trunk port can receive CDP packets that include any VLAN ID in the allowed VLAN list for that trunk
port. For more information on VLANs, see the Cisco Nexus 7000 Series NX-OS Layer 2 Switching Configuration
Guide.
VTP Feature Support
CDP sends the VLAN Trunking Protocol (VTP) type-length-value field (TLV) if the following conditions
are met:
• CDP Version 2 is enabled
• The VTP feature is enabled
Cisco Nexus 7000 Series NX-OS System Management Configuration Guide
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Configuring CDP