EOIP

RouterOS Beginner Basics
1

Greetings to everyone!

I need to know is eoip tunnel decreasing MTU on the interfaces? what if i have 30 bridged eoip tunnels on one machine?

I want to start using eoip tunnels instead transparent bridges on my network, so i need to know is there some better solution to use than EOIP?

Thanks in advance!

2

EoIP doesn’t “decrease the MTU” on any interface. The EoIP interface itself will transport a 1500 byte MTU just fine. Since the EoIP interface is encapsulating Ethernet frames in IP packets and sending those IP packets on networks supporting 1500 byte MTU’s (usually) then the IP layer will fragment the packet into two when the encapsulated Ethernet packet is over 1448 bytes (if I remember correctly). The packets gets reessembled at the other side and the original Ethernet frame is, thus, transported correctly. The only side affect is that your overhead goes up because of the IP fragment.

Bridge together 30 EoIP’s? Sure its possible but it sounds like you’re building a large layer-2 network. Do so at your own risk.

3

Hi!

Thank you for the quick answer!

I need to know what other thing can i do instead bridging those 30 EOIP’s?
1 EOIP = 1 AP in my network.
I’m bridging these tunnels in concentrator.

Best regards!

4

bridge an l2tp tunnel directly using ppp profiles. only in 3.x however.

5

Setup a layer-3 routed network.

6

Nightstar, i’ve a deployed network with the layout you are looking for..
One PPPoE Concentrator, EoIPs to APs carried by a OSPF routed network.
But i’m planning to implement VPLS and replacing EoIPs once i’m sure VPLS is reliable enough. (at least as EoIPs are)