A.Attempt to TELNET from the router connected to the inside of the firewall to the router connected to theoutside of the firewall. If telnet works， BGP will work， since telnet and BGP both use TCP to transportdata.
B.Ping from the router connected to the inside interface of the firewall to the router connected to theoutside interface of the firewall. If you can ping between them， BGP should work， since BGP uses IP totransport packets.
C.There is no way to make BGP work across a firewall without special configuration， so there is no simpletest that will show you if BGP will work or not， other than trying to start the peering session.
D.There is no way to make BGP work across a firewall.

A.ip pim rp-address
B.ip pim ssm
C.ip pim sparse-mode
D.ip pim passive

A.MD5
B.There is no Type 0 authentication
C.SHA1
D.Null

A.UDP/1812
B.UDP/1813
C.TCP/1812
D.TCP/1813

A.The MPLS header is 2 bytes，and the EXP field is 3 bits long.
B.The MPLS header is 1 byte，and the EXP field is 3 bits long.
C.The MPLS header is 4 bytes，and the EXP field is 3 bits long.
D.The MPLS header is 3 bytes，and the EXP field is 3 bits long.