多项选择题
A.cell loss priority （CLP） B.discard eligibility （DE） C.head error control （HEC） D.generic flow control （GFC） E.forward explicit congestion notification （FECN）
A.Layer 2 access link QoS design B.enterprise-to-service-provider mapping models C.Layer 3 link access QoS design D.service provider service level agreements E.Layer 2 link access load balancing
A.MD5 has been used by BGP to encrypt BGP update packets. B.BGP uses a message-digest algorithm to authenticate BGP peers C.A plain-text password authentication is an option of BGP authentication D.EBGP peers authentication is faster than IBGP peers authentication E.BGP uses public key and private key to authenticate BGP peers.