Which three configuration options are available for configuring the l2tp-class command in L2TPv3？（）

单项选择题WhichBGPattributecanbeusedtoinfluenceinboundtrafficflow？（）

A.cluster ID
B.Weight
C.MED
D.local preference
E.aggregate

多项选择题Whatarethetwobenefitsofgracefulrestart？（）

A.Graceful restart allows session information recovery without disruption to the network.
B.A node can perform a graceful restart to help a neighbor recover its state. The label bindings are kepton state information， which helps the failed node recover faster and does notaffect the current for wardtraffic.
C.Graceful restart allows a node to recover state from its neighbor when there is no RP or before thedevice undergoes SSO.
D.Graceful restart does not allow session information recovery.
E.During a graceful restart， the router removes any stale prefixes after a timer for stale entries expires

多项选择题WhichthreearetheATMcellheaderfields？（）

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）

多项选择题WhenyoudesignQoSonCEforanMPLSLayer2VPN，whichthreethingsshouldbeconsidered？（）

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

单项选择题WhichdescriptionofBGPauthenticationistrue？（）

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.