How to build a triple "ethernet repeater station"?

[RegTester]

Hi,

I've got three embedded devices which are p2p connected to each other, meaning:

A <> B

A <> C

B <> C

Now I want to be a "ethernet repeater" between all three connections.

A <> me <> B

A <> me <> C

B <> me <> C

meaning, that all trafic goes through me. So I can delay, discard or alter the telegrams at my will.

I want to do this because my task is to test the reliabilty, robustness, timing, ... of those three connections.

I will use three IP aliases, so that A, B and C will communicate with normal IP-Adresses as before,

but those telegrams will get to me and I decide what to do with those telegrams.

Normally I will send the telegram to the normal destination, as a "ether repeater" would do.

I have got a HP 1810-8G and now I want to figure out how to configure the switch.

Net1: A and me

Net2: B and me

Net3: C and me

A, B and C should not be able to communicate directly with each other,

but me should be able to communicate to A, B and C, depending on their IP-addresses.

Therefor I will propably have to set permanently the correct mac-adresses via

arp -s ip-A mac-A

arp -s ip-B mac-B

arp -s ip-C mac-C

to assure that the mac-address-based switching will go to the right port of the switch.

If A, B or C sends a telegram he can do this only with the mac address of me, because the arp-telegrams

can only be answered by me.

So, if A sends a telegram to B, I will get it, and I will decide if I send it to B or instead to C, delay it, alter it, ...

In every Net (1, 2 or 3) my communication partner (A, B oder C) will think he is normally connected and

he communicates with B, C or A.

I've tried the task with VLANs but i cannot configure the me-port into three vlans, and if I use an "old school" ethernet hub to "triple me to three ports", I will have every telegramm from me in every single net (1, 2 and 3), which I NOT want.

How do I have to configure the 1810 (Trunk, VLAN, tagged/untagged, management port, ...)?

Kind regards

Martin, hoping you can help me

[Vince-Whirlwind]

The hardest part of what you are trying to do is this:

"if A sends a telegram to B, I will get it, and I will decide if I send it to B or instead to C,delay it, alter it, "

You might be able to do some of this at Layer2 (A, B, & C are on the same subnet and communicate by addressing each other's MAC), using Policy-based routing and Layer2 access lists, and NOT, 

"If A, B or C sends a telegram he can do this only with the mac address of me".

Alternatively, if you want, 
"If A, B or C sends a telegram he can do this only with the mac address of me"
to be true, then you need A, B, and C to all be in different subnets, with the switch performing the routing.

Essentially, 

"I want to be a "ethernet repeater" between all three connections."

contradicts

"If A, B or C sends a telegram he can do this only with the mac address of me"

You're either a layer2 device, with all devices in the same subnet, or you are Layer3, with all devices in 3 different subnets joined by a router.

The 1810 is a very basic switch which doesn't allow a whole lot of network management - just a bit of stuff you can change in the GUI. I'm pretty sure it's not going to support policy-based routing, let alone this "delay it, alter it" stuff..