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I need to buy multiport NIC, because I need to replace 4 NIC with one. For example they are:

https://www.amazon.com/HP-NC364T-Gigabit-Server-Adptr/dp/B000P0NX3G

https://www.amazon.com/Intel-1000-Server-Adapter-EXPI9404VT/dp/B002JLKNIW/ref=pd_sim_147_3?_encoding=UTF8&psc=1&refRID=76TR3GM741H58F7MFJXZ

but the question is: Because this need to change multiple network cards, every port will be connected to the different network. Are those ports only for load balancing or they can work as separate ports (have different IPs)?

And how would, for example, Xen Server recognise this card, will it add 4 ports?

Marko Farkas
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  • I suggest https://forums.servethehome.com/index.php?threads/cheapskates-guide-to-intel-nics-aka-friends-dont-let-friends-buy-realtek.2663/ as great reading when it comes to selecting multiport NICs. TL;DR: If you want intel and your version of xenserver supports it, consider the i350-T4 . – rackandboneman Nov 20 '17 at 15:19
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    Just a quick warning, the HP card you've linked has some interesting issues with some versions of Linux, unless you're using a kernel/distro version that has drivers explicitly listed on the HP website the kernel will only recognise 2 ports of the card, rendering the other 2 useless. (I've had this issue and am yet to find a solution to it) – RobbG Nov 20 '17 at 17:07
  • You might wish to explore trunking of VLANs and bonding instead of separate disjoint physical interfaces for each network. Depends on decent managed switching though, ideally stacked for redundancy. – Criggie Nov 21 '17 at 03:08

3 Answers3

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These devices are typically seen in the OS as four separate network devices and they can be used just like the four separate NICs you had before.

Sven
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As others have already mentioned, yes, a 4-port network card will be recognized and usable just like 4 separate network interfaces.

However, in particular with 4-port cards, you should pay attention to the bus bandwidth the card is capable of. For example, the Intel EXPI9404VT in your second link has a PCIe 1.1 x4 bus interface, meaning that it has a total bandwidth of about 1 gigabyte per second in each direction. That's plenty for four 1-gigabit network interfaces.

Sometimes there are cheaper multi-port network cards whose bus bandwidth is less than the total bandwidth of their network ports. These can be useful if you need only connectivity to several networks, not sustained full performance. With today's PCIe bus, you're not too likely to come across this until you work with 10Gig network ports, but it's a thing to keep in mind if you need a lot of network ports in an older server.

telcoM
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    1 Gigabyte bus bandwidth to support half a gigabyte of actual traffic is only "plenty" if the drivers are programmed and used in a very very efficient manner. This is more like a road exactly two cars wide... – rackandboneman Nov 20 '17 at 17:56
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yes it will be recognized as 4 different ports, with 4 different mac addresses, and you should see 4 interfaces where you can assign 4 IPs

olivierg
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