This modular adapter has a DB9 female connector that plugs into DB9 RS232 serial port and converts it to an RJ45 connection. These modular adapters convert from a DB9 to an RJ45 socket jack (female).
eBay
2Pcs BNC Female to RJ45 Male Adapter Connector,RF Female To RJ45 Male Plug Coaxial Chassis Panel Mount Monitor Accessorie
Aliexpress UK
This modular adapter has a DB9 female connector that plugs into DB9 RS232 serial port and converts it to an RJ45 connection. These modular adapters convert from a DB9 to an RJ45 socket jack (female).
eBay
USB 3.2 Type C To RJ45 Network Card 5Gbps USB to Ethernet Adapter 100/1000/5000Mbps RJ45 Lan Gigabit Converter For PC Laptop
Aliexpress UK
This modular adapter has a DB9 female connector that plugs into DB9 RS232 serial port and converts it to an RJ45 connection. These modular adapters convert from a DB9 to an RJ45 socket jack (female).
eBay
Rj45 to screw terminal Block 8p connector ethernet rj45 Male Female to 8 pin screw terminal network adapter cable for CCTV DVR
Aliexpress UK
This modular adapter has a DB9 female connector that plugs into DB9 RS232 serial port and converts it to an RJ45 connection. These modular adapters convert from a DB9 to an RJ45 socket jack (female).
eBay
1080P HD 4K HDMI-compatible Extender RJ45 Ports Network 30M to RJ45 Over CAT5e / 6 UTP LAN Extender Cable Adapters
Aliexpress UK
Type: to DB9 female, to DB9 male(optional). Length: 50cm, 1m, 1.5m, 2m, 3.0m, 5m(optional). Multilayer shielding, fast speed transmission.
eBay
1000Mbps 1 in 4 Out Ethernet Adapter 1 to 2/4 RJ45 LAN Internet Splitter Cat 6 RJ45 Gigabit Switch for PC Laptop TV Box Router
Aliexpress UK
9 Pin RS232 Serial to RJ45 Ethernet Cable Adapter Port for Cisco Console1.5METER
eBay
5Pin XLR to RJ45 Adapter Cable,XLR 5Pin Male to RJ45 CAT5/6 Male Connector Extension Ethernet Cord for Amplifier,KTV Equipment
Aliexpress UK
This modular adapter has a DB9 female connector that plugs into DB9 RS232 serial port and converts it to an RJ45 connection. These modular adapters convert from a DB9 to an RJ45 socket jack (female).
eBay
XLR 5Pin to RJ45 Ethernet Cable,XLR 5Pin Female to UTP RJ45 CAT5/6 Male Network Extension Adapter Converter for Speaker Mixer
Aliexpress UK
Model: US013. Interface Type: USB to RJ45. Item Type: Adapter Cable. Colour: Black. 1 x Adapter Cable. Cable Length: Approx. 1.5m / 1.6yd. Support System: For /OS X / System.
eBay
2.5G Gigabit PCI-E To RJ45 Network Card Ethernet PCIE 100/1000/2500Mbps 1 Port RJ45 LAN Card Controller Adapter For Win7/8/10/11
Aliexpress UK