- Bind the service to localhost or a private network, never to a public address.
- Enable authentication, use per-application accounts and require TLS.
- Watch for exposed Docker ports: publish them on 127.0.0.1 only.
Port 25100: IBM Db2 Client Interface - Encrypted
Port 25100 is assigned by IANA to db2c-tls (IBM Db2 Client Interface - Encrypted).
25100
How db2c-tls works
Databases & cachesThe application sends a SQL query to the db2c-tls server on port 25100, which returns rows from its tables. Everything is encrypted: someone on the path only sees unreadable bytes.
- Transport
- TCP
- Exposure risk
- not rated depends on the program listening
- Encryption
- EncryptedTLS or built-in crypto
- IANA status
- Assigned1 registered service
- Range
- Registered (1024-49151)
- Category
- Databases & caches
Is port 25100 dangerous?
We have no specific security note for port 25100. Its risk depends on the program actually listening on it. General advice for databases & caches services:
IANA registry entries for port 25100
| Service | Port | Transport | Description | Reference | Updated |
|---|---|---|---|---|---|
| db2c-tls | 25100 | TCP | IBM Db2 Client Interface - Encrypted | - | 2024-03-05 |
| - | 25100 | - | Reserved | - | - |
// source: IANA service name and port number registry
Which program uses port 25100, and is it reachable?
Linux
sudo ss -ltnup 'sport = :25100' # process listening on 25100
sudo lsof -nP -i :25100macOS
sudo lsof -nP -i :25100
Windows (PowerShell)
Get-NetTCPConnection -LocalPort 25100 -State Listen | Select LocalAddress, OwningProcess Get-NetUDPEndpoint -LocalPort 25100 netstat -ano | findstr :25100
From another machine
nmap -p 25100 -sV <host> nc -zv <host> 25100
Block it in the firewall
sudo ufw deny 25100/tcp # Linux (ufw) New-NetFirewallRule -DisplayName "Block 25100" -Direction Inbound -LocalPort 25100 -Protocol TCP -Action Block # Windows
What is port 25100 used for?
Port 25100 is assigned by IANA to db2c-tls (IBM Db2 Client Interface - Encrypted).
Is port 25100 TCP or UDP?
Port 25100 is registered for TCP.
Is it safe to open port 25100?
It depends on the program that listens on it. Open it only for a service you know and only to the networks that need it. Bind the service to localhost or a private network, never to a public address.
How do I check if port 25100 is open?
On Linux run "ss -ltnup 'sport = :25100'", on macOS "lsof -nP -i :25100", and on Windows "netstat -ano | findstr :25100" to see the local process. From another machine, "nmap -p 25100 <host>" shows whether it is reachable.
Other databases & caches ports
:3306 MySQL / MariaDB tcp · udp · high risk :1433 Microsoft SQL Server tcp · udp · high risk :5432 PostgreSQL tcp · udp · high risk :6379 Redis tcp · critical risk :27017 MongoDB tcp · critical risk :9200 Elasticsearch tcp · udp · critical risk :1521 Oracle Database tcp · udp · high risk :11211 Memcached tcp · udp · high risk