4 nines = 99.99 %.
That means the probability that a link fail is 0.01 % or 0.0001 in terms of probability (scale 0 - 1).
Assuming independence, The probability that both link fails is 0.0001 x 0.0001 = 10-8, which gives back 99.999999.
Yup, that's 8 nines and not 5, but we usually don't consider more than 5 nines.
Note that Assuming independence, is in ...
A link that is 99.99% reliable is down 0.01% or 0.0001 of the time. So if the downtime of the two links is independent then both lines will be simultaneously down 0.00000001 of the time. Your link is in-theory up 99.999999% of the time.
In practice though you don't usually get the full benefits because of other factors.
Do you know how independent the ...
MSTP/RSTP isn't required when all multiple links are aggregated.
However, you'd likely want to activate and configure STP anyway as it protects your network in case an accidental loop is created. Without STP, the loop causes a broadcast storm, bringing down your network. Note that xSTP must be active on the device creating the loop, so you need to configure ...
If your are having two route for different gateways for same destination . Then one route will act as active and another one as passive this can be accomplished by adding AD value higher than one ..
route add 172.20.100.4 mask 255.255.255.255 10.22.0.9 1
route add 172.20.100.4 mask 255.255.255.255 10.192.168.18 2
If you have a fully switched ring MSTP/RSTP is required to avoid the otherwise resulting bridge loop. xSTP blocks one of the links, so it can't be used any more. The routers (L3) can only use what the switches (L2) allow them to.
You have two basic choices:
(best) Migrate to routed links. Routed links can be all activate without a problem. Additionally, ...
If you plan to create a ring of switches, all those switches need to support RSTP or MSTP.
That is, unless all the unmanaged switches completely ignore IEEE 802.1D and actually forward the RSTP BPDUs - which is very ugly but quite common. (That way, the RSTP switch sees its own BPDUs from one ring port coming in through the other one, and blocks the one with ...
I'm adding an answer to the question as the supplier found the solution to the issue we were experiencing. I'm merely adding here his explanation, it could be useful to anyone else incurring in this event. Thank you again!
[13 April 2021 12:31]
I found the solution that you need to add the Virtual MAC address on one of the interfaces of both EDR.