Introduction to IS-IS
NANOG 20, Washington DC
October 22-24
Abe Martey
amartey@cisco.com
Presentation_ID
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Topics
1. IS-IS Overview
2. IS-IS Protocol Concepts
3. CLNP Addressing
4. IS-IS Database
5. MPLS TE Extensions for IS-IS
6. ISP Network Design Considerations
7. Configuration Examples
8. Basic Troubleshooting
9. Further Reading
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1. IS-IS Overview
Terminology and Acronyms
Intermediate system (IS)- Router
Designated Intermediate System (DIS) - Designated Router
Pseudonode - Broadcast link emulated as virtual node by DIS
End System (ES) - Network Host or workstation
Network Service Access Point (NSAP) - Network Layer Address
Subnetwork Point of attachment (SNPA) - Datalink interface
Packet data Unit (PDU) - Analogous to IP Packet
Link State PDU (LSP) - Routing information packet
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IS-IS Overview
• The Intermediate Systems to Intermediate
System Routing Protocol (IS-IS) was originally
designed to route the ISO Connectionless Network
Protocol (CLNP) . (ISO10589 or RFC 1142)
• Adapted for routing IP in addition to CLNP
(RFC1195) as Integrated or Dual IS-IS
• IS-IS is a Link State Protocol similar to the Open
Shortest Path First (OSPF). OSPF supports only IP
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IS-IS Overview
• IS-IS is an Interior Gateway Protocol (IGP) - for
Intra-domain (AS) routing
• BGP provides inter-domain routing for IP
networks
• ISO-IGRP is a Cisco proprietary routing
protocol that can be used between CLNP
domains
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IS-IS Overview
• 3 network layer protocols play together to
deliver the ISO defined Connectionless
Network Service
- CLNP
- IS-IS
- ES- IS - End System to Intermediate System
Protocol
• All 3 protocols independently go over
layer 2
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IS-IS Overview
• CLNP is the ISO equivalent of IP for datagram
delivery services (ISO 8473, RFC 994)
• ES-IS is designed for routing between network
hosts and routers (ISO9542, RFC 995).
• IS-IS for layer 3 routing between routers. (ISO
10589/RFC 1142). Integrated IS-IS (RFC 1195) works
within the ISO CNLS framework even when used for
routing only IP.
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IS-IS Overview
• End System Hellos (ESH) from Hosts and
Intermediate System Hellos (ISH) from Routers
used for ES-IS neighbor discovery
• Intermediate System to Intermediate Systems
Hellos (IIH) are used for establishing IS-IS layer3
adjacencies
• ES-IS is somehow tied into IS-IS layer 3
adjacency discovery. ES-IS enabled automatically
when IS-IS is configured on Ciscos
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2. IS-IS Protocol Concepts
• Nodes
• Links
• Areas and Adjacencies
• Level-1 and level-2 routing
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IS-IS Protocol Concepts
Network Nodes
• Hosts
• Level-1 Routers
• Level-2 Routers
• Level-1 and Level-2 Pseudonodes on
broadcast links only
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IS-IS Protocol Concepts
Network Nodes
DIS
DIS
PSN
• Broadcast link represented as virtual node, referred to as
Pseudonode (PSN)
• PSN role played by the Designated Router (DIS)
• DIS election is preemptive, based on interface priority with
highest MAC address being tie breaker
• IS-IS has only one DIS. DIS/PSN functionality supports
database synchronization between routers on a broadcast type
link
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IS-IS Protocol Concepts
Network/Link Types
• Point-to-Point Links (PoS, ptp FR, ptp ATM)
• Broadcast Links (Multi-point/multi-access, ie
Ethernet, mpt FR, mpt ATM or Cisco DPT)
• Non-broadcast multi-access treated as broadcast or
point-to-point by configuration
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IS-IS Protocol Concepts
Areas
Area 49.001
Level-1
Area
L1
L1L2
Level-2
Backbone
Area 49.0002
Level-1
Area
L1
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L1L2
Area 49.003
L1L2
Level-1
Area
L1
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IS-IS Protocol Concepts
IS-IS Adjacencies
• IIH advertised for detecting neighbor
and forming network layer
adjacencies
• 3 types of IIHs:
– Point-to-point
– LAN Level-1
– LAN Level-2
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IS-IS Protocol Concepts
Point-to Adjacencies
Bytes
R
Intra-domain Routing Protocol Discriminator
1
Length Indicator
1
Version/Protocol ID Extension
1
ID Length
1
R
R
PDU Type
1
Reserved
1
Maximum Area Addresses
1
Circuit Type
Source ID
Only two way communication
required on pt-to-pt links by ISO
10589
•
3-way reliable process recently
proposed for standardization in
the IETF. Introduces pt-to-pt
adjacency state TLV (Type 240)
ID Length
2
PDU Length
2
Local Circuit ID
1
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•
1
Holding Time
TLV Fields
Pt-to-pt IIH used to establish
level-1 or Level-2 pt-to-point
adjacency
1
Version
Reserved (6 bits)
•
Variable Length
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IS-IS Protocol Concepts LAN
(Broadcast link) Adjacencies
bytes
Lenth Indicator
1
1
Version/Protocol ID Extension
1
ID Length
1
Intradomain Routing Protocol Descr.
R
R
R
PDU Type
Maximum Area Addresses
1
1
1
1
Reserved/Circuit type
1
Version
Reserved
Source ID
Priority
ID Length
2
2
1
Lan ID
ID Length + 1
Holding Time
PDU Length
R
TYPE LENGTH FIELDS
Holding Time = Hello Interval x Hello Multiplier
Priority - Interface Priority for DIS arbitration
LAN ID - System ID of DIS + PSN number
• LAN Level-1 and LAN Level-2 IIH
multicast independently to AllL1ISs
(01-80-C2-00-00-14) and AllL2ISs (0180-C2-00-00-14)
• 3-way reliable adjacency formation
can be enforced due to IS neighbors
TLV (Type 2) appended to LAN IIHs
Variable
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IS-IS Protocol Concepts
Hierarchical Routing
Backbone
Area 49.0002
Area 49.001
Level-1
Routing
Level-1
Routing
Level-2
Routing
• IS-IS supports 2-level routing hierarchy
• Routing domain is carved into areas. Routing in an area is
level-1. Routing between areas is level-2
• All ISO 10589/RFC1195 areas are stubs
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IS-IS Protocol Concepts
IS-IS Packet Types
• IS-IS Hello Packets (IIH)
Level 1 LAN IS-IS Hello
Level 2 LAN IS-IS Hello
Point-to-point Hello
• Link State Packets (LSP)
Level 1 and Level 2
• Complete Sequence Number packets (CSNP)
Level 1 and Level 2
• Partial Sequence Number Packets (PSNP)
Level 1 and Level 2
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3. CLNS Addressing
• NSAP Format
• AFI Values
• Requirements and Caveats
• Examples
• Globally unique NSAPs
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CLNS Addressing
NSAP Format
Area ID
AFI
Variable length Area address
1 byte
1 - 12 bytes
Sys ID
NSEL
System ID
NSEL
6 bytes
1 byte
• NSAP format has 3 main components
– Area ID
– System ID
– N-Selector (NSEL) - value is 0x00 on a router
• NSAP of a router is also called a NET
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CLNS Addressing
AFI Values
Address Domain
AFI Value
X.121
ISO DCC
ISO 6523
Local
37
39
47
49
• X.121 - Int’l plan for public data networks
• ISO DCC - Data country code
• IS0 6523 ICD - Telex
• Local - For local use within network domain only
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CLNS Addressing
Requirements and Caveats
• At least one NSAP is required per node
• All routers in the same area must have a common
Area ID
• Each node in an area must have a unique System ID
• All level 2 routers in a domain must have unique
System IDs relative to each other
• All systems belonging to a given domain must have
System IDs of the same length in their NSAP
addresses
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CLNS Addressing
Requirements and Caveats
• Multiple NSAPs allowed on Cisco routers for
merging, splitting or renumbering
• All NSAPs on the same router must have the
same system ID.
• The maximum size of an NSAP is 20 bytes
• Minimum of 8 bytes allowed on Ciscos.
1 byte for area, 6 bytes for system ID and 1 byte for N-selector.
AFI prefix recommended to make minimum of 9 bytes
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CLNS Addressing
NSAP Examples
Example 1
47.0001.aaaa.bbbb.cccc.00
Area = 47.0001, SysID = aaaa.bbbb.cccc, NSel = 00
Example 2
39.0f01.0002.0000.0c00.1111.00
Area = 39.0f01.0002, SysID = 0000.0c00.1111, NSel = 00
Example 3.
49.0002.0000.0000.0007.00
Area = 49.0002, SysID = 0000.0000.0007, Nsel = 00
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CLNS Addressing
How do most ISP define System IDs?
Router A#
Interface Loopback 0
IP address 192.168.3.25
Router isis
Net 49.0001.1921.6800.3025.00
IP Address conversion process:
192.168.3.25 -> 192.168.003.025
|
V
1921.6800.3025
|
V
49.001.1921.6800.3025.00
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CLNS Addressing
Globally Unique NSAPs
• AFI 47 (ISO 6523 ICD) is allocated via national
sponsoring authority of the International
Registration Authority (RA), usually a national
standards body
NIST - allocated IDI 0005 and 0006
BSI subsidiary IOTA allocated 0124 for assignment of
ATM End Systems Addresses
• AFI 39 also administered through national
institutions
IDI 0840 allocated to ANSI
NIST - United States National Institute of Standards
BSI - British Standards Institute
IOTA -Identifiers for Organizations for Telecommunications Addressing
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CLNS Addressing
Globally Unique NSAPs
47 0124 XXXXX YYYYYYYYYYYYYY AABBCCDDEEFF 00
AFI
IDI
ORG ID
ORG ASSIGNED
SYS ID
NSEL
Globally unique NSAPs make sense for interconnected
telecommunications systems such as ATM switches, SONET/SDH
ADMs that use CLNS based applications for management. For ISP
networks, the local AFI (49) would just be fine! Why?
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4. IS-IS Link State Database
• Link State Packets
• Sequence Number Packets
• More on IS- IS Metrics
• Flooding
• Database Parameters, Flags and Timers
• SPF Algorithm
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IS-IS LS Database
Link State Packets
LSP: RTB.00-00
LSP: RTC.00-00
RTC
RTB.
RTA
LSP: RTA.00-00
RTD.
LSP: RTD.00-00
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RTE
LSP: RTE.00-00
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IS-IS LS Database
IS-IS Packet Format
IS-IS Packets are made of the following:
• A Fixed Header
Contains generic packet information and
other specific information about the packet
• Type, Length, Value (TLV) Fields
TLVs are blocks of specific routing-related
information in IS-IS packets
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IS-IS LS Database
Generic Packet Format
No. of Octets
Intra-domain Routing Protocol Discriminator
1
Length Indicator
1
R
Version/Protocol ID Extension
1
ID Length
1
R
R
PDU Type
1
Version
1
Reserved
1
Maximum Area Addresses
1
Packet-Specific Header Fields
TLV Fields
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IS-IS LS Database
LSP Format
Octets
Intradomain Routing Proto Descriminator
Lenth Indicator
Version/Protocol ID Extension
R
R
1
1
1
PDU Type
Version
Reserved
1
Maximum Area Addresses
2
PDU Length
2
ID Length + 2
4
2
Remaining Lifetime
LSP ID
Sequence Number
Checksum
P
ATT
LSPDBOL
1
1
ID Length
R
1
1
1
IS Type
Variable
TYPE LENGTH VALUE FIELDS
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IS-IS LS Database
LS Packet Identifier (LSPID)
00c0.0040.abcd.02-01
Sys ID
PSN
ID
LSP
No.
• Sys ID - System ID of IS or DIS in case of PSN LSP.
• PSN ID - Zero for Non-PSN LSP and Non-zero for PSN LSP
• LSP Number - Fragmentation number
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Complete Sequence Number Packets
(CSNPs)
• Describes all known LSPs in the LS Database
• Standard IS-IS packet format
Fixed Header and
TLV Fields
• Each TLV includes the following info about each known
LSP:
LSP ID
Remaining Lifetime
Sequence number
Checksum
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Partial Sequence Number Packets
(PSNPs)
• PSNPs are similarly constructed as
CSNPs but have summaries of only
specific LSPs
• PSNPs are used in 2 ways:
– To acknowledge receipt of LSP on pt-to-pt links
– To request transmission of the latest version of an
LSP
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Level-1 TLVs
TLV Name
Area Address
Type
Origin
1
2
ISO 10589
3
ISO 10589
10
ISO 10589
IP Internal Reachability Information
128
RFC 1195
Protocols Supported
129
RFC 1195
IP Interface Address
132
RFC 1195
Intermediate System Neighbors
End System Neighbors
Authentication information
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ISO 10589
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Level-2 TLVs
TLV Name
Area Address
Type
Origin
1
2
ISO 10589
ISO 10589
4
5
10
ISO 10589
ISO 10589
ISO 10589
IP Internal Reachability Information
128
RFC 1195
Protocols Supported
129
RFC 1195
IP External Reachability Information
130
RFC 1195
Inter-domain Routing Protocol Information
131
IP Interface Address
132
RFC 1195
RFC 1195
Intermediate System Neighbors
Partition Designated Level-2 IS
Prefix Neighbors
Authentication information
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New TLVs
TLV Name
Extended IS Reachability Information
Type
22
Comments
TE Extension. Replaces TLV 2
Router-Id
134
TE Extension
Extended IP Reachability Information
135
TE extension used in place of
TLV 128 or 130
Dynamic Hostname Information
137
For dynamic distribution of
Hostname to NET mapping via
LSP Flooding
Point-to-Point Adjacency State
240
Reliable Pt-to-pt adjacency
formation
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Old IS-IS Metrics
• ISO 10589 specifies 4 metric types
Default - Supported by all routers.
Delay - measures transit delay
Expense - Measures the monetary cost of link utilization
Error - measures error probability
• Default metric type must be supported by all
implementations
• Other metric types specified for QoS
routing. Not supported in Cisco IOS and
most other vendor implementations
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Old IS-IS Metrics
• Metric Information is carried in the
following TLVs:

IS Neighbors

ES Neighbors

Prefix Neighbors

IP Internal Reachability

IP External Reachability

Extended IP Reachability

Extended IS Reachability
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Old IS-IS Metrics
Byte(s)
0
S
I/E
I/E
S
S
Default Metric (6 bits)
1
1
I/E
Delay Metric
Expense Metric
I/E
Error Metric
1
1
IP Address
4
Subnet Mask
4
• Maximum metric per interface is 63
• Maximum path metric is 1023
• There is no automatic assignment based on interface bandwidth
• Cisco uses default of 10 on all interfaces regardless of bandwidth
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Flooding and LSDB
synchronization
• Acknowledgement-based reliable
mechanism on pt-to-point links
• Flooding on broadcast links depends on
periodic advertisements of CSNPs for
reliable flooding and synchronization
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SRM and SSN Flags
.
• Send Routing Message flag (SRMflag) and
Send Sequence Number flag (SSNflag) are
used by the Update Process to control
delivery and acknowledgement of LSPs
SRMFlag - If set for a LSP on a specific
link, indicates the LSP should be flooded
on that link
SSNFlag - If set for a LSP on a link, means
send a PSNP over that link to acknowledge
receipt of LSP
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Flooding on Pt-to-pt links
RTA
RTB
RTC
Interface 1
Interface 4
Interface 2
LSP
RTA.00-00
SEQ#100
PSNP
RTA.00-00
SEQ#100
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Interface 3
LSP
RTA.00-00
SEQ#100
PSNP
RTA.00-00
SEQ#100
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Flooding on Broadcast Links
RTX
RTA (DIS)
RTB
RTC
RTX
LSP
RTX.00-00
SEQ#1
PSNP
RTX.00-00 RTA
SEQ#1
RTA
RTA
LSP
RTX.00-00
SEQ#1
CSNP
RTA.00
RTB.00
RTC.00
RTX.00
RTA
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X
PSNP
RTX.00-00
SEQ#1
RTB
PSNP
RTX.00-00
SEQ#1
RTC
LSP
RTX.00-00
SEQ#1
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IS-IS Database Timers
Timer
Maxage
LSP Refresh Interval
LSP Transmission Interval
Default Value Cisco IOS Command
1200s
isis max-lsp-interval
isis refresh-interval
900s
33ms
isis lsp-interval
LSP Retransmit Interval
5s
isis retransmit-interval
CSNP Interval
10s
isis csnp-interval
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SPF Algorithm
• Shortest Path First Algorithm (SPF), also known
as Dijkstra (named after Dutch Mathematician) is
used by link state protocols to obtain best paths
through network
• Works by building shortest path tree from
calculating router (root) to all destinations in the
network
• SPF Process runs over level-1 and level-2
databases separately
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SPF Algorithm
• In default mode, SPF process runs no
frequent than every 5s
• Full SPF is run when topology changes
• When leaf elements such as IP prefixes
change, routing table is adjusted with Partial
Route Calculation (PRC)
• PRC evaluates only routes that changed
hence less CPU intensive and relatively
fast
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SPF Algorithm
• Duration of SPF depends on many factors
such as:
Number of nodes
Number of links
Number of IP prefixes
Degree of mesh (especially for NBMA)
Speed of Route Processor
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5. IS-IS Extensions for MPLS TE
• Wide Metrics
• Extended IS Reachability Information
• Extended IP Reachability Information
• Sub TLVs
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IS-IS Extensions for MPLS TE
Wide Metric
TLV Name
Type
Extended IS Reachability Information
22
Extended IP Reachability Information
135
Comments
TE Extension to replace
TLV 2
TE extension to IS-IS, used
in place of TLV 128 or 130
• Traffic engineering extensions to IS-IS introduces reuse
fields for non-implemented QoS metrics for larger Default
metric values in TLV 22 and TLV 135
• 3 byte metric field in TLV 22
• 4 byte metric field in TLV 135
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IS-IS Extensions for MPLS TE
TLVs 22
• Type (1 byte): 22
• Length (1 byte): Total Length of Value Field
• Value:
3 bytes default metric information
7 bytes of system ID + pseudonode number
1 byte of length of sub-TLVs
0-244 bytes of sub-TLVs
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IS-IS Extensions for MPLS TE
TLVs 135
• Type (1 byte): 135
• Length (1 byte): Total Length of Value Field
• Value:
4 bytes default metric information
1 byte of control information
1 bit up/down status
1 bit sub-TLV presence indication
6 bits prefix length
0-4 bytes of IPV4 Prefix
0-250 bytes of optional sub-TLVs
1 byte to specify length of sub-TLVs
0-249 bytes of sub-TLVs
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IS-IS Extensions for MPLS TE
Sub-TLVs
Sub-TLV Name
Type
Length (bytes)
IPV4 Interface Address
3
6
4
4
IPV4 Neighbor Address
8
4
Maximum Link Bandwidth
9
4
Reservable Link Bandwidth
Unreserved Link Bandwidth
10
11
4
Administrative Group ( color )
32
• Sub-TLVs are used to flood MPLS TE resource
information and link attributes
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6. ISP Network Design
Considerations
• Sub-Optimal Level 1 Routing
• 2 Layer Domain-wide Prefix
distribution
• Running IS-IS over NBMA
• Routing Convergence
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ISP Network Design Considerations
Sub-optimal level-1 routing
• IS - IS Areas in 1142 and RFC 1195 are
stubs.
• No inter-area routes leaked from L-1-2
• L-1 routers point default to nearest L-1-2
router based on attach bit set in L-1 LSP
by level-1-2 routers
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ISP Network Design Considerations
Sub-optimal level-1 routing
Area 49.001
RTA
L1
Backbone Area 49.0002
RTC
10
OC12
RTE
RTF
L1L2
L1
L1L2
10
RTB
L1
L1L2
10
OC48
RTD
• RTA points default towards RTC because it is closer
• Nearest L2 Router may not be best path out
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ISP Network Design Considerations
Sub-optimal level-1 routing
Area 49.001
RTA
L2
RTC
10
OC12
RTE
RTF
L2
10
L2
RTB
L2
L2
10
L2
OC48
RTD
• Workaround is to put every router into single area
and run level-1 or level-2 routing
• Make every router level-1 or level-2 only. By
default Cisco routers come up as level-1-2
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ISP Network Design Considerations
Domain Wide Prefix Distribution
• AKA Route Leaking
• Allows L-1-2 routers to advertise inter-area
routes into L1
• L1 routers can then determine optimal
paths for destinations in other areas
• Allows scaling IS-IS networks by building
hierarchy into network architecture
• draft-ietf-isis-domain-wide-02.txt
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ISP Network Design Considerations
Mesh-group
RTA
RTB
RTC
RTD
RTE
• Configure RTA, RTB,RTC, RTD into mesh-group to
reduce redundant flooding. RTE on Redundant path
• LSPs received from a member of mesh-group will be
flooded to only non-members
• draft-balya-parker-mesh-00.txt
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ISP Network Design Considerations
Routing Convergence
• Current networks configured for stability
and decent convergence
• Optimizing for faster convergence
desirable given improved quality of optical
links
• Risks in case of unexpected instabilities
Constant LSP regeneration
Extra Flooding
Processor intensive SPF runs, etc
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ISP Network Design Considerations
Routing Convergence
• Challenges with SPF reduced by PRC
• Redundant flooding can be alleviated with mesh-groups
• Distributed or separate forwarding engines should take
load off Route Processors
• Above gains have been leveraged to improve routing
convergence in some versions of Cisco IOS.
• How? By using small hold-downs and short interval
between SPF runs and intelligent stabilization algorithms
in case of persistent churns
• Enhancements in Cisco IOS 12.1 provide 8x faster
convergence than current 12.0S releases for large
networks of the order of 1000s
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7. Configuring IS-IS on Ciscos
• Basic Configuration
• Multi-point configuration (ATM and FR)
• Typical ISP router configuration
• Default route
• Redistribution and Summarization
• MPLS TE Configuration
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Basic Configuration
GSR1 12.1.1.0/24
.8
GSR2
.2
e0
GSR4
.5
198.168.1.4/30
Pos1/0
hostname GSR2
clns routing
!
interface Loopback0
ip address 13.1.1.2 255.255.255.0
ip router isis SJ
interface Ethernet0
ip address 12.1.1.2 255.255.255.0
ip router isis SJ
!
interface POS2/0
ip address 10.1.1.1 255.255.255.252
ip router isis SJ
!
router isis SJ
net 49.0001.0000.0000.0002.00
!
clns host GSR1 49.0001.0000.0000.0008.00
© 1999, Cisco Systems, Inc.
.6
Pos1/0
hostname GSR4
clns routing
!
interface Loopback0
ip address 13.1.1.2 255.255.255.0
ip router isis SJ
!
interface POS2/0
ip address 10.1.1.2 255.255.255.0
ip router isis SJ
!
router isis SJ
net 49.0002.0000.0000.0004.00
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Verifying Operation
show clns neighbors
GSR2#show clns neighbors
System Id
GSR1
GSR4
Interface SNPA
State Holdtime Type Protocol
Et0
00d0.58eb.d601 Up 8
L1L2 IS-IS
PO2/0
*HDLC*
Up 25
L2 IS-IS
GSR2#show clns neighbors detail
System Id Interface SNPA
State Holdtime Type Protocol
GSR1
Et0
00d0.58eb.d601 Up 9
L1L2 IS-IS
Area Address(es): 49.0001
IP Address(es): 12.1.1.8*
Uptime: 00:08:57
GSR4
PO2/0
*HDLC*
Up 24
L2 IS-IS
Area Address(es): 49.0002
IP Address(es): 10.1.1.2*
Uptime: 00:24:08
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Verifying operation
show clns interface
GSR2#sh clns interface pos2/0
POS2/0 is up, line protocol is up
Checksums enabled, MTU 4470, Encapsulation HDLC
ERPDUs enabled, min. interval 10 msec.
RDPDUs enabled, min. interval 100 msec., Addr Mask enabled
Congestion Experienced bit set at 4 packets
CLNS fast switching disabled
CLNS SSE switching disabled
DEC compatibility mode OFF for this interface
Next ESH/ISH in 43 seconds
Routing Protocol: IS-IS
Circuit Type: level-1-2
Interface number 0x0, local circuit ID 0x100
Level-1 Metric: 10, Priority: 64, Circuit ID: GSR4.00
Number of active level-1 adjacencies: 0
Level-2 Metric: 10, Priority: 64, Circuit ID: GSR2.00
Number of active level-2 adjacencies: 1
Next IS-IS Hello in 2 seconds
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Verifying operation
show clns interface
GSR2#sh clns interface e0
Ethernet0 is up, line protocol is up
Checksums enabled, MTU 1497, Encapsulation SAP
ERPDUs enabled, min. interval 10 msec.
RDPDUs enabled, min. interval 100 msec., Addr Mask enabled
Congestion Experienced bit set at 4 packets
CLNS fast switching disabled
CLNS SSE switching disabled
DEC compatibility mode OFF for this interface
Next ESH/ISH in 4 seconds
Routing Protocol: IS-IS
Circuit Type: level-1-2
Interface number 0x1, local circuit ID 0x1
Level-1 Metric: 10, Priority: 64, Circuit ID: GSR1.01
Number of active level-1 adjacencies: 1
Level-2 Metric: 10, Priority: 64, Circuit ID: GSR1.01
Number of active level-2 adjacencies: 1
Next IS-IS LAN Level-1 Hello in 3 seconds
Next IS-IS LAN Level-2 Hello in 5 seconds
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Verifying operation
show clns protocol
GSR2#sh clns protocol
IS-IS Router: SJ
System Id: 0000.0000.0002.00 IS-Type: level-1-2
Manual area address(es):
49.0001
Routing for area address(es):
49.0001
Interfaces supported by IS-IS:
Loopback0 - IP
Ethernet0 - IP
POS2/0 - IP
Redistributing:static
Distance: 110
RRR level: none
Generate narrow metrics: level-1-2
Accept narrow metrics: level-1-2
Generate wide metrics: none
Accept wide metrics: none
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Verifying Operation
show isis topology
GSR2#sh isis topology
IS-IS paths to level-1 routers
System Id
Metric Next-Hop
GSR2
-GSR1
10
GSR1
IS-IS paths to level-2 routers
System Id
Metric Next-Hop
GSR2
-GSR4
10
GSR4
GSR1
10
GSR1
© 1999, Cisco Systems, Inc.
Interface
SNPA
Et0
00d0.58eb.d601
Interface
SNPA
PO2/0
Et0
*HDLC*
00d0.58eb.d601
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Verifying Operation
show isis database level-n detail <lspid>
GSR2#show isis database level-1 detail GSR2.00-00
IS-IS Level-1 LSP GSR2.00-00
LSPID
LSP Seq Num LSP Checksum LSP Holdtime
GSR2.00-00
* 0x0000000E 0xDAE4
1197
Area Address: 49.0001
NLPID:
0xCC
Hostname: GSR2
IP Address: 13.1.1.2
Metric: 10
IP 12.1.1.0 255.255.255.0
Metric: 10
IP 10.1.1.0 255.255.255.252
Metric: 10
IP 13.1.1.2 255.255.255.255
Metric: 10
IS GSR2.02
Metric: 10
IS GSR1.01
Metric: 0
ES GSR2
© 1999, Cisco Systems, Inc.
ATT/P/OL
1/0/0
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Verifying Operation
show isis database level-n detail <lspid>
GSR2#show isis database level-2 detail GSR2.00-00
IS-IS Level-2 LSP GSR2.00-00
LSPID
LSP Seq Num LSP Checksum LSP Holdtime
GSR2.00-00
* 0x0000000E 0x08B5
986
Area Address: 49.0001
NLPID:
0xCC
Hostname: GSR2
IP Address: 13.1.1.2
Metric: 10
IS GSR2.02
Metric: 10
IS GSR1.01
Metric: 10
IS GSR4.00
Metric: 10
IP 10.1.1.0 255.255.255.252
Metric: 10
IP 12.1.1.0 255.255.255.0
Metric: 10
IP 13.1.1.2 255.255.255.255
© 1999, Cisco Systems, Inc.
ATT/P/OL
0/0/0
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Verifying Operation
show isis database level-n detail <lspid>
GSR2#sh isis dat level-1 detail GSR1.01-00
IS-IS Level-1 LSP GSR1.01-00
LSPID
LSP Seq Num LSP Checksum LSP Holdtime
GSR1.01-00
0x00000007 0xAF8E
616
Metric: 0
IS GSR1.00
Metric: 0
IS GSR2.00
ATT/P/OL
0/0/0
• Pseudonode LSP (GSR1.01-00) is generated by GSR1
which is DIS on ethernet0 of GSR2
• PSN LSP Lists all known routers connected to LAN
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Verifying Operation
show ip route [isis]
GSR2#sh ip route
Codes: C - connected, S - static,
i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
10.0.0.0/30 is subnetted, 1 subnets
C
10.1.1.0 is directly connected, POS2/0
12.0.0.0/24 is subnetted, 1 subnets
C
12.1.1.0 is directly connected, Ethernet0
13.0.0.0/32 is subnetted, 3 subnets
i L1 13.1.1.8 [115/20] via 12.1.1.8, Ethernet0
i L2 13.1.1.4 [115/20] via 10.1.1.2, POS2/0
C
13.1.1.2 is directly connected, Loopback0
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ATM Multi-pt Configuration
GSR3
GSR4
.3
10.1.1.0/24
.4
hostname GSR3
!
clns routing
hostname GSR4
!
clns routing
!
!
interface ATM6/0.1 multipoint
interface ATM6/0.1 multipoint
ip address 10.1.1.3 255.255.255.0
ip address 10.1.1.4 255.255.255.0
no ip directed-broadcast
no ip directed-broadcast
ip router isis
ip router isis
atm pvc 1 0 8 aal5snap
atm pvc 1 0 8 aal5snap
map-group GSR_Lab
map-group GSR_Lab
!
!
router isis
router isis
net 49.0001.0000.0000.0003.00
net 49.0001.0000.0000.0004.00
is-type level-2-only
is-type level-2-only
!
!
map-list GSR_Lab
map-list GSR_Lab
ip 10.1.1.4 atm-vc 1 broadcast
ip 10.1.1.3 atm-vc 1 broadcast
clns 49.0001.0000.0000.0004.00 atm-vc 1 broadcast clns 49.0001.0000.0000.0003.00 atm-vc 1 broadcast
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ATM Multi-pt Configuration
GSR3#sh clns neighbors
System Id
Interface SNPA
GSR4
AT6/0.1 VC 1
State Holdtime Type Protocol
Up 7
L2 IS-IS
GSR3#show clns int atm6/0.1
ATM6/0.1 is up, line protocol is up
Checksums enabled, MTU 4467, Encapsulation ATM
ERPDUs enabled, min. interval 10 msec.
RDPDUs enabled, min. interval 100 msec., Addr Mask enabled
Congestion Experienced bit set at 4 packets
CLNS fast switching disabled
CLNS SSE switching disabled
DEC compatibility mode OFF for this interface
Next ESH/ISH in 8 seconds
Routing Protocol: IS-IS
Circuit Type: level-1-2
Interface number 0x0, local circuit ID 0x1
Level-2 Metric: 10, Priority: 64, Circuit ID: GSR4.01
Number of active level-2 adjacencies: 1
Next IS-IS LAN Level-2 Hello in 7 seconds
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ATM Pt-to-pt Configuration
GSR3
GSR4
.3
10.1.1.0/24
hostname GSR3
!
clns routing
!
interface ATM6/0.2 point-to-point
ip address 192.168.1.1 255.255.255.252
no ip directed-broadcast
ip router isis
atm pvc 2 0 10 aal5snap
!
router isis
net 49.0001.0000.0000.0003.00
is-type level-2-only
© 1999, Cisco Systems, Inc.
.4
hostname GSR4
!
clns routing
!
interface ATM6/0.2 point-to-point
ip address 192.168.1.2 255.255.255.252
no ip directed-broadcast
ip router isis
atm pvc 2 0 10 aal5snap
!
router isis
net 49.0001.0000.0000.0004.00
is-type level-2-only
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ATM Point-pt Configuration
GSR3#show clns neighbors
System Id
Interface SNPA
GSR4
AT6/0.2 VC 2
GSR4
AT6/0.1 VC 1
State Holdtime Type Protocol
Up 26
L2 IS-IS
Up 9
L2 IS-IS
GSR3#show clns int atm6/0.2
ATM6/0.2 is up, line protocol is up
Checksums enabled, MTU 4467, Encapsulation ATM
ERPDUs enabled, min. interval 10 msec.
RDPDUs enabled, min. interval 100 msec., Addr Mask enabled
Congestion Experienced bit set at 4 packets
CLNS fast switching disabled
CLNS SSE switching disabled
DEC compatibility mode OFF for this interface
Next ESH/ISH in 16 seconds
Routing Protocol: IS-IS
Circuit Type: level-1-2
Interface number 0x1, local circuit ID 0x100
Level-2 Metric: 10, Priority: 64, Circuit ID: GSR3.00
Number of active level-2 adjacencies: 1
Next IS-IS Hello in 3 seconds
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Frame Relay Multi-pt Configuration
RTA
.1
RTB
FR CLOUD
.2
192.168.1.0/24
hostname RTA
!
clns routing
!
interface Serial0
ip address 192.168.1.1 255.255.255.0
ip router isis
encapsulation frame-relay
frame-relay map clns 200 broadcast
frame-relay map ip 192.168.1.2 200
!
router isis
net 49.0002.0000.0000.0001.00
is-type level-2-only
© 1999, Cisco Systems, Inc.
Hostname RTB
!
clns routing
!
interface Serial0
ip address 192.168.1.2 255.255.255.0
ip router isis isp
encapsulation frame-relay
frame-relay map clns 200 broadcast
frame-relay map ip 192.168.1.1 200
!
router isis
net 49.0001.0000.0000.0002.00
is-type level-2-only
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Typical ISP Router Configuration
GSR1#
interface Loopback0
ip address 172.160.250.1 255.255.255.255
!
interface POS1/0
ip address 192.168.1.1 255.255.255.0
isis metric 100 level-2
isis hello-interval 12 level-2
isis hello-multiplier 5 level-2
isis retransmit-interval 100
!
router isis SJ
summary-address 172.160.0.0 255.255.0.0
passive-interface Loopback0
distance 15 ip
net 49.0001.0001.0000.0001.0002.0001.1721.6025.0001.00
is-type level-2-only
metric-style wide
spf-interval 30
log-adjacency-changes
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default-information originate
Used for originating default into level-2
Level-1 routers automatically point default to nearest
level-2 router based on attach bit information
Hostname RTE
!
router isis SJ
default-information originate
net 49.0002.0000.0000.0002.00
!
© 1999, Cisco Systems, Inc.
RTB#sh isis database RTE.00-00 detail level-2
IS-IS Level-2 LSP RTE.00-00
LSPID
LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
RTE.00-00
* 0x0000008D 0xDBD0
848
0/0/0
Area Address: 49.0002
NLPID:
0x81 0xCC
IP Address: 172.16.2.2
Metric: 10 IS RTE.01
Metric: 10 IS RTB.00
Metric: 0 IP-External 0.0.0.0 0.0.0.0
Metric: 20 IP 172.16.5.16 255.255.255.252
Metric: 20 IP 172.16.5.12 255.255.255.252
Metric: 10 IP 172.16.5.4 255.255.255.252
Metric: 10 IP 172.16.2.0 255.255.255.0
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Verifying Operation
show isis database
GSR2#sh isis database
IS-IS Level-1 Link State Database
LSPID
LSP Seq Num LSP Checksum
GSR2.00-00
* 0x00000008 0x7399
GSR1.00-00
0x00000002 0x7307
GSR1.01-00
0x00000003 0xB78A
LSP Holdtime
716
545
574
ATT/P/OL
1/0/0
1/0/0
0/0/0
IS-IS Level-2 Link State Database
LSPID
LSP Seq Num LSP Checksum
GSR2.00-00
* 0x00000009 0xC049
GSR4.00-00
0x00000009 0x71D6
GSR1.00-00
0x0000626A 0x1963
GSR1.01-00
0x0000696F 0x32C2
LSP Holdtime
1054
999
701
906
ATT/P/OL
0/0/0
0/0/0
0/0/0
0/0/0
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Summarization
RTB
172.16.5.0/30
172.170.1.0/24
.5
RTE
.
6
hostname RTB
!
interface Ethernet0
ip address 172.170.1.1 255.255.255.0
ip router isis SJ
!
router isis SJ
summary-address 172.170.0.0 255.255.0.0
net 49.0001.0000.0000.0001.00
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Summarization
RTE#sh ip route
Gateway of last resort is not set
i L2 172.170.0.0/16 [115/20] via 172.16.5.5, Serial 0
172.16.0.0/16 is subnetted, 1 subnets
C
172.16.5.4/30 is directly connected, Serial0
RTB#sh isis dat RTB.00-00 l2 detail
IS-IS Level-2 LSP RTB.00-00
LSPID
LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
RTB.00-00
* 0x00000096 0x86F6
877
0/0/0
Area Address: 49.0001
NLPID:
0x81 0xCC
IP Address: 172.170.1.1
Metric: 10 IS RTB.02
Metric: 10 IS RTE.00
Metric: 10 IS RTF.00
Metric: 10 IP 172.16.5.4 255.255.255.252
Metric: 10 IP 172.170.0.0 255.255.0.0
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Redistribution
IS-IS Domain
RTB
RTE
172.16.5.0/30
.5
172.170.1.0/24
OSPF Domain
.6
.3
.4
172.16.2.0/24
RTG
172.80.1.1/24
RTE
router ospf 1
network 172.16.2.0 0.0.0.255 area 0
!
router isis SJ
redistribute ospf 1 metric 20 metric-type internal level-2
net 49.0002.0000.0000.0002.00
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Redistribution
RTE#sh isis dat rte.00-00 level-2 detail
IS-IS Level-2 LSP RTE.00-00
LSPID
LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
RTE.00-00
* 0x000003B3 0x66A7
859
0/0/0
Area Address: 49.0002
NLPID:
0x81 0xCC
IP Address: 172.16.2.2
Metric: 10 IS RTE.01
Metric: 10 IS RTB.00
Metric: 20 IP-External 172.180.0.0 255.255.0.0
Metric: 20 IP 172.16.5.16 255.255.255.252
Metric: 20 IP 172.16.5.12 255.255.255.252
Metric: 10 IP 172.16.5.4 255.255.255.252
Metric: 10 IP 172.16.2.0 255.255.255.0
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MPLS TE Configuration
10.1.1.0/30
Pos 2/0 .1
.9
GSR1
GSR4 12.1.1.0/30
GSR2
.2
Pos 3/0
Pos 2/0
.4
Eth 0
Pos 4/0
.8
Eth 0
.5
10.1.1.8/30
Pos 2/2
Pos 4/0
.10
.6
10.1.1.4/30
GSR6
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MPLS TE Configuration
IS-IS configuration
hostname GSR2
!
mpls traffic-eng tunnels
interface Loopback0
ip address 13.1.1.2 255.255.255.255
no ip directed-broadcast
ip router isis SJ
!
interface POS2/0
ip address 10.1.1.1 255.255.255.252
ip router isis SJ
mpls traffic-eng tunnels
isis metric 100 level-2
ip rsvp bandwidth 10000 10000
!
interface POS3/0
ip address 10.1.1.9 255.255.255.252
ip router isis SJ
mpls traffic-eng tunnels
isis metric 100 level-2
© 1999, Cisco Systems, Inc.
ip rsvp bandwidth 10000 10000
!
router isis SJ
net 49.0001.0000.0000.0002.00
is-type level-2-only
metric-style wide
log-adjacency-changes
mpls traffic-eng router-id Loopback0
mpls traffic-eng level-2
!
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MPLS TE Configuration
Dynamic Path
hostname GSR2
!
interface Tunnel1
ip unnumbered Loopback0
no ip directed-broadcast
tunnel destination 13.1.1.4
tunnel mode mpls traffic-eng
tunnel mpls traffic-eng autoroute announce
tunnel mpls traffic-eng bandwidth 10000
tunnel mpls traffic-eng path-option 1 dynamic
• Tunnel is configured on head end router
• For dynamic path discovery, dynamic path option is used
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MPLS TE Configuration
Explicit Path
hostname GSR2
!
interface Tunnel2
ip unnumbered Loopback0
no ip directed-broadcast
tunnel destination 13.1.1.4
tunnel mode mpls traffic-eng
tunnel mpls traffic-eng autoroute announce
tunnel mpls traffic-eng path-option 1 explicit name ViaGSR6
!
ip explicit-path name ViaGSR6 enable
next-address 13.1.1.6
next-address 13.1.1.4
!
ip route 192.168.5.0 255.255.255.0 Tunnel2
• Tunnel is configured on head end router
• Explicit path defined
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MPLS TE Configuration
GSR2#show mpls traffic-eng tunn brief
Signalling Summary:
LSP Tunnels Process:
running
RSVP Process:
running
Forwarding:
enabled
Periodic reoptimization:
every 3600 seconds, next in 1180 seconds
TUNNEL NAME
DESTINATION STATUS STATE
GSR2_t1
13.1.1.4
up
up
GSR2_t2
13.1.1.4
up
up
Displayed 2 (of 2) heads, 0 (of 0) midpoints, 0 (of 0) tails
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MPLS TE Configuration
GSR2#sh mpls traffic-eng tunnels name GSR2_t1
Name: GSR2_t1
Status:
Admin: up
Oper: up
(Tunnel1) Destination: 13.1.1.4
Path: valid
Signalling: connected
path option 1, type dynamic (Basis for Setup, path weight 100)
Config Paramters:
Bandwidth: 1000 Priority: 7 7 Affinity: 0x0/0xFFFF
AutoRoute: enabled LockDown: disabled
InLabel : OutLabel : POS2/0, implicit-null
RSVP Signalling Info:
Src 13.1.1.2, Dst 13.1.1.4, Tun_Id 1, Tun_Instance 1
RSVP Path Info:
My Address: 13.1.1.2
Explicit Route: 10.1.1.2 13.1.1.4
Record Route: NONE
Tspec: ave rate=1000 kbits, burst=1000 bytes, peak rate=1000 kbits
RSVP Resv Info:
Record Route: NONE
Fspec: ave rate=1000 kbits, burst=1000 bytes, peak rate=Inf
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MPLS TE Configuration
Tunnel1
GSR2#sh mpls traffic-eng tunnels name GSR2_t1
Name: GSR2_t1
Status:
Admin: up
Oper: up
(Tunnel1) Destination: 13.1.1.4
Path: valid
Signalling: connected
path option 1, type dynamic (Basis for Setup, path weight 100)
Config Paramters:
Bandwidth: 1000 Priority: 7 7 Affinity: 0x0/0xFFFF
AutoRoute: enabled LockDown: disabled
InLabel : OutLabel : POS2/0, implicit-null
RSVP Signalling Info:
Src 13.1.1.2, Dst 13.1.1.4, Tun_Id 1, Tun_Instance 1
RSVP Path Info:
My Address: 13.1.1.2
Explicit Route: 10.1.1.2 13.1.1.4
Record Route: NONE
Tspec: ave rate=1000 kbits, burst=1000 bytes, peak rate=1000 kbits
RSVP Resv Info:
Record Route: NONE
Fspec: ave rate=1000 kbits, burst=1000 bytes, peak rate=Inf
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MPLS TE Configuration
Tunnel 2
GSR2#sh mpls traffic-eng tunnels name GSR2_t1
Name: GSR2_t2
Status:
Admin: up
Oper: up
(Tunnel2) Destination: 13.1.1.4
Path: valid
Signalling: connected
path option 1, type explicit ViaGSR6 (Basis for Setup, path weight 110)
Config Paramters:
Bandwidth: 0
Priority: 7 7 Affinity: 0x0/0xFFFF
AutoRoute: enabled LockDown: disabled
InLabel : OutLabel : POS3/0, 26
RSVP Signalling Info:
Src 13.1.1.2, Dst 13.1.1.4, Tun_Id 2, Tun_Instance 1
RSVP Path Info:
My Address: 13.1.1.2
Explicit Route: 10.1.1.10 10.1.1.5
Record Route: NONE
Tspec: ave rate=0 kbits, burst=1000 bytes, peak rate=0 kbits
RSVP Resv Info:
Record Route: NONE
Fspec: ave rate=0 kbits, burst=1000 bytes, peak rate=Inf
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MPLS TE Configuration
show isis database verbose
GSR2#show isis database verbose GSR2.00-00
IS-IS Level-2 LSP GSR2.00-00
LSPID
LSP Seq Num LSP Checksum LSP Holdtime ATT/P/OL
GSR2.00-00
* 0x00000009 0x5304
1125
0/0/0
Area Address: 49.0001
NLPID:
0xCC
Hostname: GSR2
Router ID: 13.1.1.2
IP Address: 13.1.1.2
Metric: 100
IS-Extended GSR6.00
Affinity: 0x00000000
Interface IP Address: 10.1.1.9
Neighbor IP Address: 10.1.1.10
Physical BW: 622000000 bits/sec
Reservable BW: 10000000 bits/sec
BW Unreserved[0]: 10000000 bits/sec, BW Unreserved[1]: 10000000 bits/sec
BW Unreserved[2]: 10000000 bits/sec, BW Unreserved[3]: 10000000 bits/sec
BW Unreserved[4]: 10000000 bits/sec, BW Unreserved[5]: 10000000 bits/sec
BW Unreserved[6]: 10000000 bits/sec, BW Unreserved[7]: 10000000 bits/sec
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MPLS TE Configuration
show isis database verbose cont’d
GSR2#show isis database verbose GSR2.00-00
[snip]
Metric: 100
IS-Extended GSR4.00
Affinity: 0x00000000
Interface IP Address: 10.1.1.1
Neighbor IP Address: 10.1.1.2
Physical BW: 2488000000 bits/sec
Reservable BW: 10000000 bits/sec
BW Unreserved[0]: 10000000 bits/sec, BW Unreserved[1]: 10000000 bits/sec
BW Unreserved[2]: 10000000 bits/sec, BW Unreserved[3]: 10000000 bits/sec
BW Unreserved[4]: 10000000 bits/sec, BW Unreserved[5]: 10000000 bits/sec
BW Unreserved[6]: 10000000 bits/sec, BW Unreserved[7]: 9000000 bits/sec
Metric: 100
IP 10.1.1.8/30
Metric: 100
IP 10.1.1.0/30
Metric: 10
IP 13.1.1.2/32
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MPLS TE
IS-IS show commands
GSR2#sh isis mpls traffic-eng ?
adjacency-log Adjacency Log
advertisements Agent advertisements
downstream-tree MPLS TE Optimized Autoroute Calculation downstream tree
tunnel
Tunnel Information
GSR2#sh isis mpls traffic-eng adjacency-log
IS-IS MPLS TE log
When Neighbor ID
IP Address
Interface Status Level
00:50:13 GSR4.00
10.1.1.2
PO2/0 Up level-2
00:50:12 GSR6.00
10.1.1.10
PO3/0 Up level-2
GSR2#sh isis mpls traffic-eng tunnel
GSR2#sh isis mpls traffic-eng tunnel
System Id
Tunnel Name Bandwidth Nexthop
GSR4.00
Tunnel2
0
13.1.1.4
Tunnel1
1000
13.1.1.4
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MPLS TE Configuration
hostname GSR4
mpls traffic-eng tunnels
!
interface Loopback0
ip address 13.1.1.4 255.255.255.255
ip router isis SJ
!
interface Loopback5
ip address 192.168.5.1 255.255.255.0
!
interface Ethernet0
ip address 12.1.1.4 255.255.255.0
ip router isis SJ
!
interface POS2/0
ip address 10.1.1.2 255.255.255.252
ip router isis SJ
mpls traffic-eng tunnels
ip rsvp bandwidth 1000 1000
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interface POS4/0
ip address 10.1.1.5 255.255.255.252
no ip directed-broadcast
ip router isis SJ
mpls traffic-eng tunnels
ip rsvp bandwidth 1000 1000
!
router isis SJ
net 49.0001.0000.0000.0004.00
is-type level-2-only
metric-style wide
mpls traffic-eng router-id Loopback0
mpls traffic-eng level-2
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MPLS TE Configuration
hostname GSR6
!
mpls traffic-eng tunnels
!
interface Loopback0
ip address 13.1.1.6 255.255.255.255
ip router isis SJ
!
interface POS4/0
ip address 10.1.1.6 255.255.255.252
no ip directed-broadcast
ip router isis SJ
mpls traffic-eng tunnels
ip rsvp bandwidth 1000 1000
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interface POS2/2
ip address 10.1.1.10 255.255.255.252
no ip directed-broadcast
ip router isis SJ
mpls traffic-eng tunnels
ip rsvp bandwidth 1000 1000
router isis SJ
net 49.0001.0000.0000.0006.00
is-type level-2-only
metric-style wide
mpls traffic-eng router-id Loopback0
mpls traffic-eng level-2
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MPLS TE Configuration
show ip route
GSR2#sh ip route
Codes: C - connected, S - static, i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area
Gateway of last resort is not set
S
192.168.5.0/24 is directly connected, Tunnel2
10.0.0.0/30 is subnetted, 3 subnets
C
10.1.1.8 is directly connected, POS3/0
C
10.1.1.0 is directly connected, POS2/0
i L2 10.1.1.4 [115/20] via 10.1.1.10, POS3/0
[115/20] via 13.1.1.4, Tunnel2
12.0.0.0/24 is subnetted, 1 subnets
i L2 12.1.1.0 [115/20] via 13.1.1.4, Tunnel2
13.0.0.0/32 is subnetted, 3 subnets
i L2 13.1.1.4 [115/20] via 13.1.1.4, Tunnel2
i L2 13.1.1.6 [115/20] via 10.1.1.10, POS3/0
C
13.1.1.2 is directly connected, Loopback0
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8. Basic Troubleshooting
• Show Commands
• Debugging Commands
• Error logs
• MPLS TE troubleshooting
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Troubleshooting
CLNS Commands
show clns int
show clns protocol
show clns neighbors detail
show clns is-neighbors
show clns es-neighbors
show clns route
show clns cache
show clns traffic
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Troubleshooting
show isis commands
show isis spf-log
show isis database detail
show isis database<lspid>
show isis route
show isis database L1|L2
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Troubleshooting
Debugging Commands
debug clns:
events CLNS error events
filters CLNS filters
packets CLNS packet switching activity
routing CLNS routing table activity
debug isis:
adj-packets IS-IS Adjacency related packets
checksum-errors IS-IS LSP checksum errors
local-updates IS-IS local update packets
snp-packets IS-IS CSNP/PSNP packets
spf-events IS-IS Shortest Path First Events
spf-statistics IS-IS SPF Timing and Statistic Data
spf-triggers IS-IS SPF triggering events
update-packets IS-IS Update related packet
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Troubleshooting
Error Logging
log-adjacency-changes Command
Used to keep track of changes in the state of adjacent neighbors
Helpful in tracking connectivity problems
RTX#show log
%CLNS-5-ADJCHANGE: ISIS: Adjacency to 0000.0000.0001 (ethernet 0)
%CLNS-5-ADJCHANGE: ISIS: Adjacency to 0000.0000.0002 (ethernet 0)
BAD Clns Packet Errors
Nov 16 02:18:04.848 EDT: %CLNS-4-BADPACKET: ISIS: P2P hello, option 8
length 53 remaining bytes (51) from VC 2 (ATM4/0.2)
Nov 16 02:18:04.848 EDT: ISIS: P2P hello, option 8 length 53 > remaining
bytes (51) from VC 2 (ATM4/0.2)
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Troubleshooting
SPF Logs
RTB#sh isis spf-log
Level 1 SPF log
When
Duration Nodes Count Triggers
00:25:27 8
4
1
PERIODIC
00:18:09 12
5
2
NEWLSP TLVCONTENT
00:10:27 8
5
1
PERIODIC
Level 2 SPF log
When
Duration Nodes Count Triggers
00:40:35 8
3
1
PERIODIC
00:25:35 8
3
1
PERIODIC
00:18:17 8
3
1
TLVCONTENT
00:10:34 8
3
1
PERIODIC
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Troubleshooting
MPLS TE
• Show mpls traffic-eng tunnel
• show mpls traffic-eng topology
• show mpls traffic-eng autoroute
• show mpls traffic-eng link advertisements
• show isis traffic-eng tunnels
• show isis database [verbose|detail]
• show ip rsvp
• Debug traffic-eng path calc
• debug ip rsvp
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9. Further Reading
• ISO 8473 Connectionless Network Protocol (CNLP)
• ISO 10589 ISO IS-IS Routing Protocol
• ISO 9542 ES-IS Routing Protocol
• ISO 8348/Ad2 Network Services Access Points
• RFC 1195 Integrated (Dual) IS-IS
• RFC 1237 Guidelines for OSI NSAP allocation in the Internet
• http://www.cisco.com/univercd/cc/td/doc/product/software/i
os113ed/113ed_cr/np1_c/1cisis.htm
• http://www.cisco.com/univercd/cc/td/doc/product/software/i
os121/121newft/121t/121t3/traffeng.htm
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9. Further Reading
• RFC Drafts:
• draft-ietf-isis-traffic-02.txt
• draft-ietf-isis-3way-01.txt
• draft-ietf-isis-domain-wide-01.txt
• draft-ietf-isis-dyname-01.txt
• draft-hsmit-mpls-igp-spf-00.txt
• draft-ietf-isis-hmac-00.txt
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Q and A
•Thank You
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