Help me understand LACP
Help me understand LACP
Hey guys, So I am planning to use LACP on my servers, but I'm a bit confused as to how LACP or ethernet bonding works. 1. Are the connections bonded, between two machines, or between a server and a switch? 2. What if a non-LACP machine wants to connect to a LACP bonded connection? Will it have reduced speed, or no connection at all? 3. So if I have a LACP bonded link with 2 connections bonded together(1 Gigabit each) and if 2 separate machines(Also 1 Gb each) try to download data from the server, will the bandwidth be shared between the two separate clients? (So, basically, its a 2:1 connection) (Also assuming the server can saturate the effectively 2Gbit link) 4. If anyone has used this, let me know any other nuances or /things/ that I need to know before jumping on LACP. My use case is for performance improvement(No redundancy etc) Thanks!
They connect through the server and the switch. If you need to use a port channel with two gigabit ports, you can send traffic from the server to the switch using two gigabits. LACP is applied on the server's NIC and the switch's interface. It acts as a bonding method for those ports. The devices themselves aren't "LACP machines." In this case, each machine will be limited to one gigabit. If you have four machines attempting to download LACP, it may try to balance the load but won't be flawless—still aiming for about 500 Mbps per device, depending on timing. Now it's simpler and more affordable to buy a switch with two 10Gb ports and let it operate normally. You can get them for under $200. LACP can be tricky on some systems (like certain servers), but it works fine and is a solid protocol. I hope this clarifies things.
If your switch supports a 10GbE port, consider installing a 10GbE card on your server and linking it to the switch, then extending it to all connected devices. LACP should function, but if the server encounters issues with the NIC card—perhaps due to a malfunction—it may drop connections and you might need to restart the server or adjust the NIC settings. This is something that could occur occasionally. Another concern arises because LACP distributes traffic based on various protocols, defaulting to destination MAC addresses. With many devices constantly sending large amounts of data, traffic can become unevenly balanced across the two 1Gb ports, leading to performance hiccups. If you have the option, opt for 10GbE; otherwise, LACP still works but comes with its own characteristics.
I've been experimenting with LAG and found it quite cumbersome. Perhaps LACP would be more dependable, though it required several attempts to get it up and running. I'm not fully confident in its stability. There are occasional packet drops on the interface. I intend to upgrade to 10Gb as soon as I can afford it—it just doesn't seem worth the effort. If it's mission-critical, I shouldn't compromise on quality.