RP/0/0/CPU0:02-PE2#show cef 172.16.21.3/32 detail
Mon Jul 7 13:08:51.966 UTC
172.16.21.3/32, version 3138, internal 0x4004001 0x0 (ptr 0xacbb75a4) [1], 0x0 (0xacbb2d24), 0x410 (0xacc338bc)
Updated Jul 7 12:59:17.265
Prefix Len 32, traffic index 0, precedence n/a, priority 4
gateway array (0xacb6405c) reference count 15, flags 0xf0, source rib (6), 0 backups
[6 type 5 flags 0x10111 (0xacc38408) ext 0x0 (0x0)]
LW-LDI[type=5, refc=3, ptr=0xacbb2d24, sh-ldi=0xacc38408]
via 172.16.10.3, 3 dependencies, recursive [flags 0x6000]
path-idx 0 NHID 0x0 [0xacec1a24 0x0]
next hop 172.16.10.3 via 16008/0/21
local label 16019
next hop 172.16.10.3/32 tt31 labels imposed {ImplNull 300640} <========== goes via RSVP tunnel 31
Load distribution: 0 (refcount 6)
Hash OK Interface Address
0 Y Unknown 16008/0
RP/0/0/CPU0:02-PE2#show mpls traffic-eng tunnels 31 detail
Mon Jul 7 13:11:55.793 UTC
Name: tunnel-te31 Destination: 172.16.10.3
Signalled-Name: LSP-COR-PE2--->ASBR1
Status:
Admin: up Oper: up Path: valid Signalling: connected
path option 1, type dynamic (Basis for Setup, path weight 1000)
Last Signalled Error: Mon Jul 7 09:35:12 2014
Info: [40] PathErr(23,4)-(system) at 10.1.0.11
G-PID: 0x0800 (derived from egress interface properties)
Bandwidth Requested: 0 kbps CT0
Creation Time: Wed Jul 2 15:50:21 2014 (4d21h ago)
Config Parameters:
Bandwidth: 0 kbps (CT0) Priority: 7 7 Affinity: 0x0/0xffff
Metric Type: TE (default)
Hop-limit: disabled
AutoRoute: enabled LockDown: disabled Policy class: not set
Forward class: 0 (default)
Forwarding-Adjacency: disabled
Loadshare: 0 equal loadshares
Auto-bw: disabled
Fast Reroute: Disabled, Protection Desired: None
Path Protection: Not Enabled
BFD Fast Detection: Disabled
Reoptimization after affinity failure: Enabled
Soft Preemption: Disabled
SNMP Index: 13
History:
Tunnel has been up for: 00:13:04 (since Mon Jul 07 12:58:52 UTC 2014)
Current LSP:
Uptime: 00:12:55 (since Mon Jul 07 12:59:01 UTC 2014)
Reopt. LSP:
Last Failure:
LSP not signalled, identical to the [CURRENT] LSP
Date/Time: Mon Jul 07 12:59:01 UTC 2014 [00:12:55 ago]
Prior LSP:
ID: 44 Path Option: 1
Removal Trigger: reoptimization completed
Current LSP Info:
Instance: 45, Signaling Area: OSPF core area 0
Uptime: 00:12:55 (since Mon Jul 07 12:59:01 UTC 2014)
Outgoing Interface: GigabitEthernet0/0/0/3, Outgoing Label: implicit-null <===================== tunnel has implicit null
Router-IDs: local 172.16.10.2
downstream 172.16.10.3
Soft Preemption: None
Path Info:
Outgoing:
Explicit Route:
Strict, 10.1.0.11
Strict, 172.16.10.3
Record Route: Empty
Tspec: avg rate=0 kbits, burst=1000 bytes, peak rate=0 kbits
Session Attributes: Local Prot: Not Set, Node Prot: Not Set, BW Prot: Not Set
Soft Preemption Desired: Not Set
Resv Info:
Record Route:
IPv4 10.1.0.11, flags 0x0
Fspec: avg rate=0 kbits, burst=1000 bytes, peak rate=0 kbits
Displayed 1 (of 3) heads, 0 (of 0) midpoints, 0 (of 3) tails
Displayed 1 up, 0 down, 0 recovering, 0 recovered heads
I have even captured the LSP ping itself, and see following:
Multiprotocol Label Switching Echo
Version: 1
Global Flags: 0x0000
0000 0000 0000 0... = Reserved: 0x0000
.... .... .... ...0 = Validate FEC Stack: False
.... .... .... ..0. = Respond only if TTL expired: False
.... .... .... .0.. = Validate Reverse Path: False
Message Type: MPLS Echo Request (1)
Reply Mode: Reply via an IPv4/IPv6 UDP packet (2)
Return Code: No return code (0)
Return Subcode: 0
Sender's Handle: 0x000052cd
Sequence Number: 1
Timestamp Sent: Jul 6, 2014 19:10:49.967036000 UTC
Timestamp Received: Jan 1, 1970 00:00:00.000000000 UTC
Vendor Private
Type: Vendor Private (64512)
Length: 12
Vendor Id: ciscoSystems (9)
Value: 0001000400000004
Target FEC Stack
Type: Target FEC Stack (1)
Length: 12
FEC Element 1: BGP labeled IPv4 prefix
Type: BGP labeled IPv4 prefix (12)
Length: 5
IPv4 Prefix: 172.16.21.3 (172.16.21.3)
Prefix Length: 32
Padding
Downstream Mapping
Type: Downstream Mapping (2)
Length: 28
MTU: 1500
Address Type: IPv4 Numbered (1)
DS Flags: 0x00
0000 00.. = MBZ: 0x00
.... ..0. = Interface and Label Stack Request: False
.... ...0 = Treat as Non-IP Packet: False
Downstream IP Address: 10.1.0.11 (10.1.0.11)
Downstream Interface Address: 10.1.0.11 (10.1.0.11)
Multipath Type: no multipath (0)
Depth Limit: 0
Multipath Length: 0
Downstream Label Element 1, Label: 3 (Implicit-Null), Exp: 0, BOS: 0, Protocol: 0 (Unknown)
Downstream Label: Implicit-Null (3)
Downstream Exp: 0
Downstream BOS: 0
Downstream Protocol: Unknown (0)
Downstream Label Element 2, Label: 3 (Implicit-Null), Exp: 0, BOS: 0, Protocol: 0 (Unknown)
Downstream Label: Implicit-Null (3)
Downstream Exp: 0
Downstream BOS: 0
Downstream Protocol: Unknown (0)
Downstream Label Element 3, Label: 304336, Exp: 0, BOS: 1, Protocol: 0 (Unknown) <=========================
Downstream Label: 304336
Downstream Exp: 0
Downstream BOS: 1
Downstream Protocol: Unknown (0)
So, two ImpNull Downstream Label Elements are included.
Why?