Pass the Cisco CCNP Enterprise 300-410 Questions and answers with ValidTests

If we modify the weight, increase local preference or use AS path prepending then we can only

make MPLS B prefer over MPLS A. But when MPLS B is down then MPLS A will be used which

does not meet the requirement of this question. Only with AS path filtering we can deny prefixes

from certain AS and make sure branch B never uses MPLS A to reach HQ.

https://community.cisco.com/t5/other-network-architecture/out-of-band-router-access/td-p/333295

The “transport output none” command prevents any protocol connection made from R1.

Therefore our SSH connection to 192.168.12.2 was refused. In order to fix this problem we can

configure “transport output ssh” under “line console 0” of R1.

Note: The parameter “-l” specifies the username to log in as on the remote machine.

The IPv6 Router Advertisement Guard feature provides support for allowing the network administrator to block or reject unwanted or rogue router advertisement guard messages that arrive at the network device platform. Router Advertisements are used by devices to announce themselves on the link. The IPv6 Router Advertisement Guard feature analyzes these router advertisements and filters out router advertisements that are sent by unauthorized devices.

Certain switch platforms can already implement some level of rogue RA filtering by the administrator configuring Access Control Lists (ACLs) that block RA ICMP messages that might be inbound on “user” ports.

Command Default

Accounting port: 1813

Authentication port: 1812

Accounting: enabled

Authentication: enabled

Retransmission count: 1

Idle-time: 0

Server monitoring: disabled

Timeout: 5 seconds

Test username: test

Test password: test

Restrictions for IPv6 RA Guard

The IPv6 RA Guard feature does not offer protection in environments where IPv6 traffic is tunneled.

This feature is supported only in hardware when the ternary content addressable memory (TCAM) is programmed.

This feature can be configured on a switch port interface in the ingress direction.

This feature supports host mode and router mode.

This feature is supported only in the ingress direction; it is not supported in the egress direction.

This feature is not supported on EtherChannel and EtherChannel port members.

This feature is not supported on trunk ports with merge mode.

This feature is supported on auxiliary VLANs and private VLANs (PVLANs). In the case of PVLANs, primary VLAN features are inherited and merged with port features.

Packets dropped by the IPv6 RA Guard feature can be spanned.

Explanation

To avoid having to rebuild the LDP session altogether, you can protect it. When the LDP session

between two directly connected LSRs is protected, a targeted LDP session is built between the two

LSRs. When the directly connected link does go down between the two LSRs, the targeted LDP session

is kept up as long as an alternative path exists between the two LSRs.

For the protection to work, you need to enable it on both the LSRs. If this is not possible, you can

enable it on one LSR, and the other LSR can accept the targeted LDP Hellos by configuring the

command mpls ldp discovery targeted-hello accept.