多选题If the OSPF protocol is used to connect customer edge （CE） routers to service provider edge（PE） routers in the VPN backbone， which two options best describe the use of SHAM links？（）AA sham-link is created between any twoo VPN sites that belong to the s

第1题：

第2题：

第3题：

第4题：

Which four statements about the Carrier Supporting Carrier （CSC） feature are true？ （）

• A、MPLS is required between the PE and CE routers that connect the backbone carrier to the customer carrier.
• B、The backbone carrier must enable the PE router to check that the packets it receives from the CErouter contain only the labels that the PE router advertised to the CE router.
• C、Every packet that crosses the backbone carrier must be encapsulated so that the packet includes MPLS labels
• D、AII PE routers that link the backbone carrier to the customer carrier must run Route Target Rewrite.
• E、Arouting protocol is required between the PE and CE routers that connect the backbone carrierto thecustomer carrier. The routing protocol enables the customer carrier to exchange IGP routing information with the backbone carrier.

第5题：

Which two features prevent routing loops between the OSPF sites of a customer when the sites aremultihomed or a backdoor link is used between the sites？ （）

• A、sham link
• B、down bit
• C、virtual link
• D、Site of Origin
• E、domain tag

第6题：

第7题：

If the OSPF protocol is used to connect customer edge （CE） routers to service provider edge（PE） routers in the VPN backbone， which two options best describe the use of SHAM links？（）

• A、A sham-link is created between any twoo VPN sites that belong to the same OSPF area and share an OSPF backdoor link
• B、A sham-link is seen as an intra-area link between PE routers，an OSPF adjacency is created and data base is exchanged
• C、A SHAM link is created between two directly connected PE routers so that it is preferred over the low speed backdoor door
• D、A SHAM link is part of OSPF network of MPLS-VPN provider

第8题：

第9题：

When implementing MPLS VPNs between CE and PE routers, which of these statements is correct? As a Network Engineer, it is necessary for you to know how to implement MPLS VPNs between Customer Edge and Provider Edge routers. Refer to the following descriptions, which one is making sense?（）

• A、If using OSPF or EIGRP as the PE-CE routing protocol, redistribution is not required, but any other protocol or static route will require redistribution
• B、If using IS-IS as the PE-CE routing protocol, no redistribution is required
• C、If using static routes between the CE and PE routers, no redistribution of other VPN routes is required
• D、If PE-CE protocol is not BGP, redistribution of other VPN routes from MP-BGP is required

第10题：

When BGP is used as the PE-CE routing protocol, which of these statements is correct?（）

• A、On the CE router, PE neighbors must be configured in the VRF context on the CE router
• B、On PE routers, the CE IBGP neighbors are configured in the global BGP configuration
• C、On PE routers, the CE EBGP neighbors are configured in the VRF context
• D、A separate BGP process must be used on the PE routers for CE routers so that they do not use the same BGP routing process as that used for the PE router's other provider neighbors