Is it possible to set up the same VLANs on two different switches with same IPs, but different MACs on dual port network cards of servers? In case switch 1 is down or needs maintenance I would like switch 2 to take over the communication between servers and vice versa as I do not want the entire network of servers to have no connectivity between each other as they are either replicas of each other or shards receiving older data, I need to make the network highly available - redundant. The whole purpose of my network is 3 shards with 3 replicas each and shards of the same app data distributed to make it fail safe, but the network is not fail safe with 1 switch in my engineering plan, yet.
Something like this:
Shard I - fresh data replicated, new incoming data - 3 servers to make it fail safe on server level server1 + server2 + server3
Shard II - server4 (less accessed data) - data moved regularly from fresh data Shard I - replica not needed (redundancy on RAID level)
Shard III - same server4, but data on Modular Storage Arrays attached to server4 - data moved here regularly from Shard II (least accessed data) - replica not needed (redundancy on RAID level)
So I need to make the network fail-safe. My idea is 2nd same switch, but have questions on the setup. Still researching how to achieve. Best method to achieve assuming both switches are not connected? Would it work, if each server is connected to both switches at the same time from different ports on their network cards? Switch used, if matters - Quanta LB6M. Any better switch to recommend for the use case? Do switches need be connected to each other? Then I could possibly try with Dell EMC PowerSwitch S4048-ON 48 10GbE SFP+, 6 40Gbps QSFP+ and use the 40GbE QSFP+ to interconnect the switches and the 10Gbe SFP+ to connect the servers to the switches. Thanks!
Yes, just make sure you trunk the VLANs to both switches (using 802.1Q tagging), see below.
Yes - if you're using different MACs, the failover isn't actually up to the switches but the hosts. Switches only care for MAC addresses and as long any of those isn't visible on different switch ports they'll be fine.
What you're looking for is called NIC teaming with one port active and the other in standby, in case the active port loses its link. Most dual-port NICs support teaming but that may also be up to the server's operating system.
Likely, you'd not only want to make the switch redundant but also the individual server links, which requires connecting the switches with a VLAN trunk.
If you can't tolerate a redunction in overall bandwidth, you may need to make sure that the link between the switches is fast enough to handle your workloads, in case traffic splits across the switches - one or more ports going down with some servers failing over. Commonly, a dual, aggregated link is used (which also handles a single link failure at that place).