Supported Ethernet card standard

[sairfan1]

I'm setting up OPNsense on Core i7 6700 HP G2 Elite 800 machine for learning purpose

This machine has a built in Intel Ethernet card, additionally i installed an Intel PCIe Ethernet card
After installing OPNsense I came to know that it only picked up additional PCIe Intel card but could not recognize built in card.

Now I want to buy a quad or dual Ethernet card for my machine I dont know what standards or types it supports, please let me know what parameters should I consider to choose an Ethernet (NIC) card/adapter.

[PacketChomper]

Now I want to buy a quad or dual Ethernet card for my machine I dont know what standards or types it supports, please let me know what parameters should I consider to choose an Ethernet (NIC) card/adapter.

Pretty much anything that is supported by Freebsd13.1 as defined in https://www.freebsd.org/releases/13.1R/hardware/#support

The Intel PRO/1000 series is popular and well regard, but of course there are other good vendors.

If you've installed OPNSense or have access to a Freebsd 13 system, you could read the man pages for igc, em or ix as they list the supported chipsets. From there you can search for cards that suit your needs.

You can also search the popular online stores for quad cards and pfSense, since it runs the same OS.