Check Point Software Technologies Ltd
Palo Alto Networks
Symantec Corp.
Fortinet, Inc.
FireEye, Inc.
Proofpoint
Imperva, Inc.
AVG Technologies
Synamtac
CISCO
Juniper
Pulse secure
Forscout
Extreme networks
Aruba
Bradford networks
InfoExpress
Impulse
Auconet
Pulse secure
Dell Sonicwall
CISCO
Citrix VPN
Aruba (Wireless Access Point)
Nokia (mobile network security)
Samsung (mobile network security)
Palo-alto
Cisco
Fortinet
Checkpoint
Paypal
Visa
Amazon (amazon pay)
Samsung (Samsung pay)
Aquasec
Sysdig
Refer here for more listings
Please refer https://www.thesoftwarereport.com/top-25-cybersecurity-companies-of-2018/
Many more are listed here
https://www.esecurityplanet.com/products/top-network-access-control-solutions.html
https://www.eletimes.com/10-biggest-cyber-security-companies-to-watch-out-for