L2 & L3 VPN

[haytham elsamadony]

Hi Guys

my question i know may be not new ..... but i really can`t find a suitable and full answer on it
i ask about the difference between MPLS L2 VPN and MPLS L3 VPN

I know about L3 VPN and understand it

but i can`t understand the L2 VPN

i can`t understand the concept .....

what is MPLS L2 VPN ..... why we use it .... why we don`t use only L3 VPN at all cases

which scenarios we must use L2 and which one we must use L3

which features on L2 can`t find on  L3

[Philip D'Ath]

A L2 service provides something that looks like a long patch lead.

It is very common between data centres, so you can have the same IP addressing at each site.

[David_Che]

Sometimes SAN servers in different data center need to communicate with each other, the only way is ethernet access as they only have MAC address and no IP address. In this scenario, only L2 VPN is feasible and possible. with L2 VPN expansion, SAN servers in different DC can communicate with each other if they are in same VLAN. 

with L2 mpls vpn, you do not need setup routing neighboring relationship with ISP PE, it can be seen as only one physical cable. you can setup routing neighboring with remote peer owned by your company.