I need to open my outbound traffic on my firewall to permit two internal (in LAN) Cisco VPN Client to connect to their VPN over Internet.
I've already open 500/UDP port, but they aren't able to connect. If I open all outbound ports, they're able to connect.
What are the ports used by Cisco VPN Client?
You need to open:
You may also need to open UDP port 4500 (if NAT-T is being used).
Further, if the clients are connecting to a VPN 3000 series Concentrator and it is configured for any of the other NAT-Transparency options, corresponding ports need to be opened. By default:
1. If IPSec over TCP 10000 is being used, then open TCP 10000.
2. If IPSec over UDP 10000 is being used, open UDP 1000.