Port 915 RIFT-TIES
Port 915 is the IANA-assigned rift-ties port for Routing in Fat Trees Topology Information Element (UDP).
What is port 915 used for?
Port 915 is assigned to rift-ties and uses UDP. The IANA registry describes the service as “Routing in Fat Trees Topology Information Element”. It sits in the well-known range, which operating systems reserve for core network services, so software expects it at this number by default.
Ports are the transport-layer address a service listens on. This entry has no TCP assignment: UDP is connectionless, so a client that gets no reply may be hitting either an idle service or a firewall drop. That is why a port conflict appears whenever two processes try to bind the same number.
Use the commands below to confirm whether port 915 is actually in use before you change firewall rules. Blocking the port stops new inbound traffic at the firewall, but it does not stop a local process from listening, and it does not remove the service from the machine.
Browse all Networking and proxies ports
Source: IANA Service Name and Transport Protocol Port Number Registry. Registered assignee: [IESG]. Reference: [RFC 9692].
Check and block port 915
Copy-ready commands for the protocols assigned to this port. Run the check first, then block only what should not be reachable.
Check on Linux
sudo ss -ulpn 'sport = :915'Check on Windows
Get-NetUDPEndpoint -LocalPort 915 -ErrorAction SilentlyContinueBlock with UFW
sudo ufw deny 915/udpBlock with iptables
sudo iptables -A INPUT -p udp --dport 915 -j DROPThese commands are examples for a typical host. Check the listener before you change firewall rules, and persist iptables rules with iptables-save or netfilter-persistent. On Windows, use Windows Defender Firewall or New-NetFirewallRule for persistent blocks. The iptables rules here cover IPv4; mirror them with ip6tables if IPv6 is enabled.
Is port 915 safe to expose?
This port is not on our curated list of services with a widely exploited profile. Exposure is only safe when the listening service is intended, patched and protected by a firewall. Keep the listening service patched and remove it if unused. A default-deny firewall policy with explicit allow rules is still the safest baseline.
Where port 915 is usually used
Most traffic on port 915 falls into these scenarios. The demo below is a safe way to confirm the listener before you change anything.
- Routers, switches and proxies exchanging routing or session information.
- Clients sending traffic through a forward or reverse proxy on port 915.
- Troubleshooting path selection, NAT or proxy rules during an outage.
Confirm the UDP listener
This port is not registered for TCP, so an nc TCP probe cannot confirm it. Run this on the host that runs the service; empty output means nothing is bound to port 915.
sudo ss -ulpn 'sport = :915'Common problems with port 915
No reply from the service
Because UDP has no handshake, a missing reply can mean the service is idle, the packet was dropped, or the client sent it to the wrong interface. Check the listener locally before blaming the network.
Port already in use
Find the process holding the port with sudo ss -ulpn 'sport = :915' or sudo lsof -i :915. Stop that process or configure it to bind another port; killing it without identifying it can take down a production service.
Firewall rule did not survive a reboot
UFW and Windows Firewall keep rules across restarts. Raw iptables rules do not: save them with iptables-save or the netfilter-persistent package, and re-apply after upgrades that reset the ruleset.
The port is blocked but still reachable
A firewall rule filters inbound traffic; it does not close the listener. Confirm with the check command above and bind the service to 127.0.0.1 when only local clients need it.
Port 915 at a glance
| Port number | 915 |
|---|---|
| Service name | rift-ties |
| Transport protocol | UDP |
| Category | Networking and proxies |
| Range | Well-known port (0–1023) |
| Risk level | Standard/Low |
| Registered assignee | [IESG] |
| Reference | [RFC 9692] |
| Registry description | Routing in Fat Trees Topology Information Element |
| Source | IANA Service Name and Transport Protocol Port Number Registry |
Frequently asked questions
What is port 915 used for?
Port 915 (RIFT-TIES) uses UDP. Routing in Fat Trees Topology Information Element.
How do I check if port 915 is open?
On Linux run `sudo ss -ulpn 'sport = :915'`. On Windows run `Get-NetUDPEndpoint -LocalPort 915 -ErrorAction SilentlyContinue` in PowerShell. If the port is open, the output shows a process listening on port 915; empty output usually means nothing is bound to it.
How do I block port 915?
With UFW run `sudo ufw deny 915/udp`. With iptables run `sudo iptables -A INPUT -p udp --dport 915 -j DROP`. Persist the iptables rules with your distribution's netfilter-persistent or iptables-save tooling so they survive a reboot.
Is port 915 safe to expose?
This port is not on our curated list of services with a widely exploited profile. Exposure is only safe when the listening service is intended, patched and protected by a firewall. Nevertheless, keep the listening service patched and remove it if unused. A default-deny firewall policy with explicit allow rules is still the safest baseline.
Related ports
Primary data: IANA Service Name and Transport Protocol Port Number Registry.
Last reviewed 2026-10-30 · Methodology · About · Privacy