# When Switches Flood LLDP Traffic

DevFeed: [When Switches Flood LLDP Traffic](<https://devfeed.tech/articles/when-switches-flood-lldp-traffic-11231.md>)

Original publisher: [Read original article](<https://blog.ipspace.net/2025/08/switches-flood-lldp/>)

Published: 2025-08-25T07:13:00Z

Content type: article

Language: en

Sources: [ipSpace.net blog](<https://devfeed.tech/sources/ipspace-net-blog.md>)

Topics: [networking](<https://devfeed.tech/topics/networking.md>), [Cisco](<https://devfeed.tech/topics/cisco.md>), [datacenter](<https://devfeed.tech/topics/datacenter.md>), [Server](<https://devfeed.tech/topics/server.md>)

Tags: [bridging](<https://devfeed.tech/tags/bridging.md>), [cisco](<https://devfeed.tech/tags/cisco.md>), [data-center](<https://devfeed.tech/tags/data-center.md>), [ethernet](<https://devfeed.tech/tags/ethernet.md>), [network](<https://devfeed.tech/tags/network.md>), [networking](<https://devfeed.tech/tags/networking.md>), [servers](<https://devfeed.tech/tags/servers.md>), [standards](<https://devfeed.tech/tags/standards.md>)

## AI overview

The article examines why Cisco switches in a data center network flood LLDP packets between servers, potentially causing DCBX parameters to be negotiated between servers and leading to NIC resets. It compares IEEE LLDP requirements with Cisco TAC's explanation for flooding on NCS equipment and discusses the role of MEF standards.

## Source excerpt

A networking engineer (let's call him Joe1) sent me an interesting challenge: they built a data center network with Cisco switches, and the switches flood LLDP packets between servers. That would be interesting by itself (the whole network would appear as a single hub), but they're also using DCBX (which is riding in LLDP TLVs), and the DCBX parameters are negotiated between servers (not between servers and adjacent switches), sometimes resulting in NIC resets2. Read more ...