Cisco Updated 300-410 Exam Questions and Answers by nahla

The first 20 bits constitute a label, which can have 2^20 values. Next comes 3 bit value called Traffic Class. It was formerly called as experimental (EXP) field. Now it has been renamed toTraffic Class (TC). This field is used for QoS related functions. Ingress router can classify the packet according to some criterion and assign a 3 bit value to this filed. If an incoming packet is marked with some IP Precedence or DSCP value and the ingress router may use such a field to assign an FEC to the packet. Next bit is Stack bit which is called bottom-of-stack bit. This field is used when more than one label is assigned to a packet, as in the case of MPLS VPNs or MPLS TE. Next byte is MPLS TTL field which serves the same purpose as that of IP TTL byte in the IP header

From the output we can see there are 2 NHRP Peers. The first one with the NBMA Address of

172.18.16.2 and the “Attribute” (Attrb) of Static (S) so we can deduce it is the Hub device.

Therefore the second one must be the remaining Spoke device with the attribute of Dynamic

(D).

-- > S - Static, D - Dynamic, I - Incomplete

N - NATed, L - Local, X - No Socket

# Ent -- > Number of NHRP entries with same NBMA peer

NHS Status: E -- > Expecting Replies, R -- > Responding, W -- > Waiting

UpDn Time -- > Up or Down Time for a Tunnel

========================================================================

==

Interface: Tunnel1, IPv4 NHRP Details

Type:Spoke, NHRP Peers:2,

# Ent Peer NBMA Addr Peer Tunnel Add State UpDn Tm Attrb

----- --------------- --------------- ----- -------- -----

1 44.44.44.4 192.168.100.254 UP 00:03:40 S

1 12.12.12.2 192.168.100.2 UP 00:03:20 D

debug ip routing This command enables debugging messages related to the routing table.