Mdns port

Author: a | 2025-04-24

A. mDNS uses only UDP port 5436 as a destination port. B. mDNS cannot use UDP port 5353 as the destination port. C. mDNS is not supported on FlexConnect APs with a locally switched serial: port: mdns: //slzb-06 port: mdns://uzg-01 port: mdns://czc Optional: disable LED of the adapter if supported (default: false) disable_led: false Optional: Baud rate speed for serial

MDNS: KC Port Orchard Project

VLAN, trunk configurations, Wireless mode settings etc. Upon successfully implementing the solution, the network administrator may optionally prune the Wired VLAN from AP trunk port if configured to enabled flood-n-learn based mDNS. Table – 2 below describes side-by-side comparison between unicast-based Local Area Bonjour and classic flood-n-learn based mDNS solution: Table 2. Unicast vs Flood-n-Learn mDNS Comparison Unicast mDNS Service-Routing Flood-n-Learn mDNS Service Management Unicast Service-Routing Flood-n-Learn Based L2 Switch Role Service-Peer Pass-Thru L2 WLC Role N/A N/A Access-Distribution Connection mDNS Trusted Trunk Standard L2 Trunk L2 Switch Flood Application Broadcast Unknown Unicast Link-Local Multicast (non-mDNS) Broadcast Unknown Unicast Link-Local Multicast Layer 2 mDNS Route – IPv4 and IPv6 Flood – IPv4 and IPv6 Service Boundary Policy-Based – Wired and Wireless Individual – Switch | VLAN | Port-Group | Port Entire Layer 2 Broadcast Domain Service Policy Security IT defined on Service-Peer Unsupported Location-Based Service Policy-Based – Wired and Wireless Individual – Switch | VLAN | Port-Group | Port Unsupported Policy management The network remains unsecure and vulnerable to manage mDNS security with classic flood-n-learn based networks. The network administrators have limited controls and visibility to identify, secure and manage mDNS services in Layer-2 network environments. As Cisco Catalyst LAN switching and Wireless portfolio introduces unicast-based mDNS service management it enables new possibilities for IT organizations to build secure and end-to-end service-routing enterprise networks. The Cisco IOS-XE 17.6.2 software version introduces new flexible policy configuration model providing network administrator to design and build simplified or custom tailored mDNS service-routing Wired This post has been republished via RSS; it originally appeared at: Microsoft Tech Community - Latest Blogs - .James Kehr here with the Windows networking support team. This article covers details about mDNS and recommended best practices when trying to control the protocol designed to make life easier.What is mDNS?Starting with Windows 10 1703 Microsoft has included native support for multicast DNS, or mDNS. The protocol was developed by Apple, via RFC 6762 and RFC 6763, as a method to perform local network name and service discovery without the need for central name resolution, such as a DNS Server, and without user interaction. Simply put, it is how Apple made AirPlay2-based services perform seamless setup via the Bonjour service.mDNS worked so well for Apple that it subsequently became the most popular many-to-many network name resolver because it uses regular old DNS over regular old IP multicast. This makes creating mDNS resolvers extremely easy as there are tons of DNS engines out there, and all major operating systems have mature multicast capabilities.Just about everything uses mDNS these days. Seriously… everything. Pop open Wireshark on your home computer, set the capture filter to “udp port 5353”, which is the mDNS protocol (UDP) and port (5353), start the capture, then wait.Devices and services from Microsoft, Apple, Google, and Amazon all use mDNS in some capacity. SmartTVs, Miracast (wireless screen mirroring), printers, set top boxes, wireless speakers, operating systems, and more all use mDNS. Most use it to resolve service records for device discovery. Others to resolve network names. Some do both. Our modern connected life wouldn’t be the same without mDNS.mDNS is everywhere these days because it is a simple, easy to build, user friendly – as in users do not need to know or do anything with mDNS for it to “just work” – network discovery protocol. Everyone in the tech industry loves mDNS, whether they know the protocol exists or not … except corporate security.Corporate security folks, in general, distrust anything that involves decentralized name resolution and multicast/broadcast in the same sentence. This includes mDNS because it is possible to poison name and service resolution with a cleverly written malicious script or program. Granted, a malicious mDNS resolver must first be on your network to do so and that, by itself, is a different kind of nightmare.There is a magic registry value in Windows that will disable mDNS in the Windows DNS client resolver. I am not going to tell you what it is, but I will tell you why you should not rely on it to disable mDNS.I mentioned that mDNS is easy to implement in the introduction of this article. In fact, it is so easy to implement that any given operating system, Windows included, could have multiple mDNS resolvers running at the same time. Chromium-based browsers (Chrome, Edge, etc.) have an mDNS resolver. Microsoft Teams has been known to use mDNS. Third-party apps and services can contain their own resolver. Oh, and those malicious programs can run their

How do I disable/block mDNS or port 5353 (mDNS) on an iPhone

Or Custom. Default Tag (0) or custom tag assigned to Wired Port and FlexConnect/EWC Mode AP Location-group based service-routing The classic mDNS flood-n-learn based Cisco Wireless FlexConnect or EWC network deployments unable to provide location-based mDNS solution for Wired and Wireless mDNS endpoints. The key challenge on LAN side is to dynamically identify, tag and extend granular location details for Wired mDNS services connection. In a Layer 2 mDNS flood environment it has not been possible to detect exact mDNS endpoint connection across Wired Layer 2 networks and distributing with granular details to FlexConnect or EWC mode Wireless endpoints. Cisco DNA Service for Bonjour solution enables zero-configuration vision with introduction of mDNS service-routing based on Location-Tag mapped to Wired LAN Ports and Cisco Wireless Access-Points. The Cisco Catalyst 9000 series LAN switches expands policy tuple with inclusion to assign Location- Group tag for service discovery and distribute mDNS services matching administrator defined tags. The mDNS service Location-Tag on Wired LAN Ports and Wireless Access Points are dynamically synchronized across complex Enterprise network environments and without introducing forklift changes impacting mission-critical network environments. Figure 7. Location-tag based service-routing As end-to-end mDNS processing transforms to unicast-based service and provides flexibility to tag mDNS services for granular service-routing, the Cisco DNA Service for Bonjour enables new possibilities for IT organization to design and implement end-to-end, secure, and scalable service-oriented solution. To provide the best-in-class user-experience the IT administrator can design and build Location-tag based dynamic mDNS service boundaries at individual building, floor, or. A. mDNS uses only UDP port 5436 as a destination port. B. mDNS cannot use UDP port 5353 as the destination port. C. mDNS is not supported on FlexConnect APs with a locally switched

Teamviewer Service listening on UDP port 5353 (mDNS)

Own mDNS resolver, too.How is this possible?Because mDNS uses the connectionless UDP protocol, and not TCP, you can have multiple listeners on UDP port 5353. I have a PowerShell command I use to demonstrate this, with sample output.Get-NetUDPEndpoint -LocalPort 5353 | Select-Object LocalAddress,LocalPort,OwningProcess,@{ Name="ProcessName"; Expression={((Get-Process -Id $_.OwningProcess).Name )} }Sample Output:LocalAddress LocalPort OwningProcess ProcessName------------ --------- ------------- -----------:: 5353 18080 msedge:: 5353 3592 svchost #DNSCache service, to confirm: tasklist /SVC /FI "PID eq "0.0.0.0 5353 55708 Teams0.0.0.0 5353 5512 chrome0.0.0.0 5353 18080 msedgeDisabling mDNS via the registry will only remove one line from that output, the svchost where the DNSCache service lives. It will not stop other first- (Microsoft) and third-party (anyone else) mDNS resolvers. It will not stop devices on your network from reaching your Windows systems with mDNS. It honestly does not do a lot if your goal is to lock down mDNS on your corporate network.What to do? What to do?The Microsoft recommendation for locking down mDNS is to use Windows Defender Firewall. This is the best tool for the job and most corporations already manage the firewall through GPOs. This makes the lock down process a matter of modifying an existing well-known process.Warning! Disabling mDNS can have unexpected negative consequences. Wireless screen sharing/mirroring in conference rooms may stop working. Accessing printers may break. Any number of other issues may creep up given broad service dependencies on mDNS.Block InboundTo completely lock down mDNS, disable the inbound “mDNS (UDP-In)” rules in Windows Defender Firewall for all profiles (Public, Private, and Domain). This will prevent all inbound mDNS traffic from being processed and effectively disable mDNS. This is not recommended for mobile workers who may need to use a device at home or client office that relies on mDNS for service discovery.To disable mDNS within corporate offices only, disable mDNS (UDP-In) for just the Domain profile. This will allow mobile workers to connect at home and on the road, but not in your offices where there is domain connectivity. This is the recommended best practice for mobile workforces.You can optionally disable mDNS (UDP-In) for the Public profile, too. This might interfere with Miracast screen sharing, which relies on the Public profile, and homes where the Private profile is not selected, but it does add an extra measure of security in public places, like a coffee shop.What About Outbound?We do not recommend blocking outbound unless your company needs the absolute strictest of network controls due to a high security requirement. Blocking inbound mDNS is sufficient for nearly all use cases.mDNS plays a critical role in modern computing. It is not like previous multicast- and broadcast-based name resolution protocols, like LLMNR, SSDP, and NbtNS, which had limited adoption and usefulness. mDNS has near universal adoption within the tech industry which makes controlling it less cut and dry. Hopefully this article will make mDNS decision process a bit easier. WLC listens for Bonjour services, caches these Bonjour advertisements (AirPlay, AirPrint, and so on) from the source/host. For example, Apple TV and responds back to Bonjour clients when they ask/request for a service. This way you can have the sources and clients in different subnets.Configure Network DiagramPacket Flow with DebugsThere are basic four steps which take place when mDNS runs on a Cisco WLC. These steps are described as follows:Step 1. When You Globally Enable mDNS on the WLCWLC listens to these default services if you does not have a customized mDNS profile created as shown in the image.Each of these services has a service string associated with it. Service strings are used to match service instances to service queries. A service type always contains the service name and the protocol. Additionally, it can contain one or more subtype identifiers. AppleTV service uses: _airplay._tcp.local.When mDNS is enabled globally, the controller sends mDNS queries to 224.0.0.251 for all the services on wired (management and dynamic interfaces) and wireless network.In this capture at WLC switch port, packets 80, 81 and 82 show WLC sends a query to 224.0.0.251 over the wired network with source IP of the management (10.48.39.142) and dynamic interfaces(192.168.232.11 and 192.168.239.8) as shown in the image.Packet 83 shows that WLC sends a query over the wireless. The inner packet shows WLC query to 224.0.0.251 from management interface. Since this query is over the wireless, capwap header is added to the packet with outer source IP still to be that

Avahi blocks mDNS port - Apps and Virtualization - TrueNAS

That advertises or queries mDNS services conforming to RFC 6762. The mDNS endpoints can be in either LANs or WLANs. The Cisco Wide Area Bonjour solution is designed to integrate with RFC 6762 compliant Bonjour services, including AirPlay, Google Chrome cast, AirPrint, Dante Audinate and more. Cisco FlexConnect Wireless Design The Cisco FlexConnect wireless network can be deployed in central-switching or local-switching modes. The fundamental design principle to align the IP gateway and mDNS gateway on Cisco Catalyst switch remains consistent regardless of the wireless deployment modes. The core benefits of designing and implementing mDNS gateway on Cisco Catalyst 9000 series Ethernet switches is that it enables unicast-based services rich wired and wireless networks within Local Area Bonjour domain. The IT organizations no need to merge Wired and Wireless VLANs or extend Wired VLANs to Cisco Wireless Access-Points for endpoints to discover mDNS services using flood-and-learn model. The Layer 2 trunk port connecting to Cisco Wireless FlexConnect or EWC AP mode shall only require carrying Wireless users VLAN providing better security, AP scalability and may improve Wireless network performance. The Cisco Wireless LAN Controller supporting FlexConnect mode Access-Points can be deployed in following supported two modes: ● Appliance-based Controller – A physical appliance system deployed in central-site supporting control-plane processing to network-wide distributed Cisco Access Points in FlexConnect Local-Switching mode. The WLC physical appliance could be next-generation Cisco Catalyst 9800 series WLC or classic Cisco AireOS series WLC. ● Cloud-based Controller – A virtual Catalyst 9800 series WLC controller system

Port 5353 (UDP) - Multicast DNS (mDNS) - WhatPortIs.com

And Wireless networks. Figure 6 – below illustrates the new Cisco IOS-XE built-in and default policy model to activate unicast-based mDNS service-routing on intended Wired VLAN or Wireless Profile. The Cisco Catalyst switch and WLC continue to support custom policy when upgrading from previous software version or need tailored policies solution. Figure 6. Flexible Cisco IOS-XE service-routing policy model The Cisco IOS-XE provides support co-existence of Default and Custom policy on same system. Based on requirement the administrator can implement policy in either or both mode on per Wired VLAN and Wireless Profile basis: Table 3. Flexible Cisco IOS-XE service-routing policy comparison Default Policy Custom Policy Local Area Bonjour – Service-List Permit Built-In. Default bi-directional services permitted * Custom. User-defined uni-directional custom service permission Local Area Bonjour – Service-Policy Built-In. Automatically binds default Service-List Custom. User-defined custom service-list binding Local Area Bonjour – Service-Policy Built-In. Automatically associates default policy to mDNS gateway enabled Wired VLAN and Wireless Profile Custom. User-defined manual policy association to mDNS gateway enabled Wired VLAN and Wireless Profile * Apple TV, AirPrint, Apple HomeSharing, Apple Remote Login (SSH), Apple ScreenShare, Apple-Windows-FileShare (SMB), Google ChromeCast, Google Expeditions, Multifunction Printers (Print, Scan, Fax), Secure-Printing services are by default permitted in service-list policy. Default Policy Custom Policy Local Area Bonjour – Wired Inter-VLAN Service-Proxy Built-In. Automatic Inter-VLAN Service-Proxy on L2 Switch Custom. User-Defined manual inter-VLAN location-filter on L2 Switch Location-Tag – Wired Port and FlexConnect/EWC Mode AP Built-In. Default Tag (0) to Wired Port and FlexConnect/EWC Mode AP Built-In. A. mDNS uses only UDP port 5436 as a destination port. B. mDNS cannot use UDP port 5353 as the destination port. C. mDNS is not supported on FlexConnect APs with a locally switched serial: port: mdns: //slzb-06 port: mdns://uzg-01 port: mdns://czc Optional: disable LED of the adapter if supported (default: false) disable_led: false Optional: Baud rate speed for serial

About MDN - The MDN project

Same subnet network.Open the Control Center and select AirPlay Mirroring on the iOS device (e.g., iPhone/iPad).Find a device prefixed with “Cast-xxxx”.If “Cast-xxxx” is showing then this confirms that vCast is broadcasting AirPlay services.Click on the broadcasted “Cast-xxxx” device to mirror your iOS device to the ViewBoard®.Chromecast ServiceViewBoard® Cast software supports native Chromecast screen sharing via the Chrome browser casting with the Chromecast feature enabled.Note: Please ensure that mDNS is enabled on the network/access point/wireless controller (if applicable).Network InformationPorts: TCP 8008 & 8009 UDP 5353 (mDNS to broadcast CCast)How to Verify Chromecast is Broadcasting:Ensure that your Chromebook and ViewBoard® are connected to the same subnet network.Bandwidth: At least 2~5 Mbps per user in a typical deployment. Latency should be less than 100 ms when pinging Google’s public DNS server at 8.8.8.8; for HD video streaming > 5 Mbps is required.Access points:For small deployments of under 30 devices, consumer-grade networking equipment is sufficient.For deployments greater than 30 devices or involving multiple rooms, enterprise-grade, centrally managed networking equipment is recommended.Note:It is recommended to use Wi-Fi 802.11n 5 GHz.Please refer to a 5 GHz channel guide for a table on non-DFS channels in your country. In the USA, those channels are 36~48 and 149~165.Display ServicemyViewBoard Display allows users to mirror their desktop wirelessly to supported Interactive Flat Panels (IFP) and Wireless Presentation Displays (WPD).myViewBoard Display comes pre-installed on select ViewBoard® hardware, but can also be installed manually on any IFP or WPD that runs Android 6 or higher.Once myViewBoard Display is installed on an IFP or WPD, users will only need to use a compatible browser to start mirroring their device screen to the host.Network InformationPorts: TCP Port 443 (HTTPS): outbound UDP and TCP port 3478 bidirectional to the WebRTC servers UDP Ports 50,000 – 65,535 (RTP/sRTP/RTCP) bidirectional to the WebRTC servers (These ports are optional; if blocked, media will be proxied using TURN on port 3478.)Manager ServicemyViewBoard Manager is a tool for Entity Administrators to remotely manage multiple installations of ViewSonic visual solution devices such as a ViewBoard®.To access, select the Entity Management tile, then All Devices on the side panel.Note: This option is only available for users signed in using an Entity Administrator account. To learn more, visit: InformationPorts: TCP Port 443 (HTTPS): bidirectionalWhitelist Domains: *.myviewboard.com *.myviewboard.cloud myviewboardclips.com *firebraseio.com *amazonaws.comMiracast ServiceMiracast helps you wirelessly stream content from Windows and Android devices to an Interactive Flat Panel (IFP) or Wireless Presentation Display (WPD).Note: Please ensure that mDNS is enabled on the network/access point/wireless controller (if applicable).Network InformationPorts: TCP Port 7236 : Wi-Fi direct control port used to establish and manage sessions between the source device and ViewBoard. UDP port 21200 for RTP packets and UDP port 21201 for RTCP packets. UDP 5353 for