L2VPN

Hi, please your help

Which of the following statements about the L2VPN are true?

a. If the length of a L2VPN packet that arrives at a P node exceeds the maximum transmission unit (MTU) of relevant interfaces of the P node, the packet will be fragmented and then forwarded.

b. When a traditional L2VPN (ATM and FR) is upgraded to an MPLS L2VPN, the network topology does not need to be adjusted.

a.  When providing the MPLS L2VPN service for enterprise users, the carrier must filter user route advertisements. Otherwise, flapping of user routes may lead to flapping of network routes.

d. On a L2VPN, routing information of users does not need to be maintained or managed.