ldp-treetrace {prefix ip-prefix/mask} [downstream-map-tlv {dsmap|ddmap}] [fc fc-name [profile profile]] [max-path max-paths] [max-ttl ttl-value] [retry-count retry-count] [timeout timeout]
oam
7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C
This command configures LDP treetrace to perform a single run of the LDP ECMP OAM tree trace. LDP treetrace tests are run to discover all ECMP paths of an LDP FEC.
Specifies the address prefix and subnet mask of the target BGP IPv4 label route.
Specifies which format of the Downstream Mapping TLV to use in the LSP trace packet. Use dsmap for the original DSMAP TLV format defined in RFC 4379. Use ddmap for the enhanced DDMAP TLV format defined in RFC 6424.
Specifies the forwarding class of the MPLS echo request packet.
When an MPLS echo request packet is generated in the CPM and forwarded to the outgoing interface, the packet is queued in the egress network queue corresponding to the specified fc and profile parameter values. The LSP-EXP mappings on the outgoing interface control the marking of the packet EXP.
When the MPLS echo request packet is received on the responding node, the LSP-EXP mappings of the incoming interface determine the fc parameter values.
When an MPLS echo reply packet is generated in the CPM and forwarded to the outgoing interface, the packet is queued in the egress network queue corresponding to the fc parameter. The parameter values is determined by the classification of the echo request packet being replied to at the incoming interface control the marking of the packet. The LSP-EXP mappings on the outgoing interface. The TOS byte is not modified. The following table summarizes the MPLS echo request packet behavior.
Node |
Packet and description of behavior |
|---|---|
CPM (sender node) |
Echo request packet:
|
Outgoing interface (sender node) |
Echo request packet:
|
Incoming interface (responder node) |
Echo request packet:
|
CPM (responder node) |
Echo reply packet:
|
Outgoing interface (responder node) |
Echo reply packet:
|
Incoming interface (sender node) |
Echo reply packet:
|
Specifies the profile state of the MPLS echo request packet.
Specifies the maximum number of paths for an LDP treetrace test, expressed as a decimal integer.
Specifies the maximum TTL value in the MPLS label for the LSP trace test, expressed as a decimal integer.
Specifies the maximum number of consecutive MPLS echo requests, expressed as a decimal integer, that do not receive a reply before the trace operation fails for a specific TTL.
Specifies the timeout, in seconds, expressed as a decimal integer. This value overrides the default timeout value. It specifies the amount of time the router waits for a message reply after sending the message request. When the message timeout expires, the requesting router assumes that the message response has not been received. Any response received after the request times out is silently discarded.
The following output is an example of LDP treetrace information.
Sample output*A:Dut-A# oam ldp-treetrace prefix 10.20.1.6/32
ldp-treetrace for Prefix 10.20.1.6/32:
127.0.0.1, ttl = 3 dst = 127.1.0.255 rc = EgressRtr status = Done
Hops: 127.0.0.1 127.0.0.1
127.0.0.1, ttl = 3 dst = 127.2.0.255 rc = EgressRtr status = Done
Hops: 127.0.0.1 127.0.0.1
ldp-treetrace discovery state: Done
ldp-treetrace discovery status: ' OK '
Total number of discovered paths: 2
Total number of failed traces: 0
[no] ldp-treetrace
config>test-oam
7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C
This command configures the LDP ECMP OAM tree trace, which includes LDP ECMP path discovery and path probing.
The no form of this command deletes the configuration for the LDP ECMP OAM tree discovery and path probing.
The following output is an example of LDP treetrace information over a numbered IP interface.
Sample output*A:Dut-B# oam ldp-treetrace prefix 10.20.1.5/32
ldp-treetrace for Prefix 10.20.1.5/32:
10.10.131.2, ttl = 2 dst = 127.1.0.253 rc = EgressRtr status = Done
Hops: 11.1.0.2
10.10.132.2, ttl = 2 dst = 127.1.0.255 rc = EgressRtr status = Done
Hops: 11.1.0.2
10.10.131.2, ttl = 2 dst = 127.2.0.255 rc = EgressRtr status = Done
Hops: 11.2.0.2
10.10.132.2, ttl = 2 dst = 127.2.0.253 rc = EgressRtr status = Done
Hops: 11.2.0.2
ldp-treetrace discovery state: Done
ldp-treetrace discovery status: ' OK '
Total number of discovered paths: 4
Total number of failed traces: 0
fc fc-name
no fc
config>test-oam>ldp-treetrace
7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C
This command configures the forwarding class of the MPLS echo request packet.
When an MPLS echo request packet is generated in the CPM and forwarded to the outgoing interface, the packet is queued in the egress network queue corresponding to the specified fc parameter values. The LSP-EXP mappings on the outgoing interface control the marking of the packet EXP.
When the MPLS echo request packet is received on the responding node, the LSP-EXP mappings of the incoming interface determine the fc parameter values.
When an MPLS echo reply packet is generated in the CPM and forwarded to the outgoing interface, the packet is queued in the egress network queue corresponding to the fc parameter. The classification of the echo request packet being replied to at the incoming interface determines the value of the fc parameter. The LSP-EXP mappings on the outgoing interface control the marking of the packet header MPLS EXP field. The TOS byte is not modified. Table: Request packet and behavior for sender and responder nodes summarizes this behavior.
The no form of this command reverts the FC type to the default value.
be
Specifies the forwarding class of the MPLS echo request packets.
path-discovery
config>test-oam>ldp-treetrace
7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C
Commands in this context configure LDP ECMP OAM path discovery.
The ingress LER sends LSP Trace messages, including the LDP IPv4 Prefix FEC TLV and DSMAP TLV to the downstream LSR to build the ECMP tree for a specific FEC (egress FEC). It also inserts an IP address range drawn from the 127/8 space. The downstream LSR uses the address range to determine the ECMP path exercised by an IP address or a subrange of addresses within the specified range based on its internal hash routine. When the ingress LER receives the MPLS echo reply, it records this information and sends the next echo request message to a node that is downstream of the first LSR node along one of the ECMP paths. The subrange of IP addresses indicated in the initial reply allows the LSR downstream of the ingress LER to pass this message to its downstream node along the first ECMP path.
Use the interval command to configure the frequency of running tree discovery.
The ingress LER gets the list of FECs from the LDP FEC database. New FECs are added to the discovery list at the next tree discovery, and not when they are learned and added into the FEC database. Use the policy-statement command to configure FECs to include or exclude the use of a policy profile.
interval minutes
no interval
config>test-oam>ldp-treetrace>path-discovery
7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C
This command configures the frequency of the LDP ECMP OAM path-discovery process. At every interval, the node sends LSP trace messages to discover the entire ECMP path tree for a specific destination FEC.
The no form of this command reverts the interval to its default value.
60
Specifies the number of minutes to wait before repeating the LDP tree auto-discovery process.
max-path max-paths
config>test-oam>ldp-treetrace>path-discovery
7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C
This command configures the maximum number of ECMP paths that can be discovered for each interval.
The no form of this command reverts the maximum number of ECMP paths to the default value.
16
Specifies the maximum number of paths for the tree discovery.
max-ttl ttl-value
config>test-oam>ldp-treetrace>path-discovery
7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C
This command configures the maximum number of hops that are traced in the path of each FEC to be discovered.
The no form of this command reverts to the maximum time-to-live (TTL) default value.
255
Specifies the maximum label TTL value for an LSP trace request during the tree discovery.
policy-statement policy-name [...(up to 5 max)]
config>test-oam>ldp-treetrace>path-discovery
7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C
This command configures FEC policy to determine which routes are imported from the LDP FEC database for the purpose of discovering the paths and probing them.
If no policy is specified, the ingress LER imports the full list of FECs from the LDP FEC database. New FECs are added to the discovery list at the next path discovery, and not when they are learned and added into the FEC database. A maximum of 500 FECs can be discovered using path discovery.
The user can configure the FECs to be included or excluded in the LDP FEC database.
Policies are configured in the config>router>policy-options context. A maximum of five policy names can be specified.
The no form of this command removes the policy from the configuration.
no policy-statement
Specifies the route policy name to filter LDP imported address FECs. Allowed values are any string up to 32 characters composed of printable, 7-bit ASCII characters. If the string contains special characters (#, $, spaces, and so on), the entire string must be enclosed within double quotes. The specified policy names must already be defined.
retry-count retry-count
no retry-count
config>oam-test>ldp-treetrace>path-discovery
config>oam-test>ldp-treetrace>path-probing
7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C
In the config>oam-test>ldp-treetrace>path-discovery context, this command configures the number of retransmissions of an LSP trace message to discover the path of an LDP FEC when no response is received within the timeout period.
In the config>oam-test>ldp-treetrace>path-probing context, this command configures the number of retransmissions of an LSP ping message to probe the path of an LDP FEC when no response is received within the timeout period.
The no form of this command reverts the retry count to the default value.
3
Specifies the maximum number of consecutive timeouts allowed before a path probe fails.
timeout timeout
no timeout
config>test-oam>ldp-treetrace>path-discovery
7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C
This command configures the maximum amount of time, in seconds, that the node waits for a response after sending an LSP Trace message sent to discover the path of an LDP FEC before it declares failure. After consecutive failures equal to the value configured for the retry-count command, the node stops sending echo requests and returns either the available results or a failure message to the user.
The no form of this command reverts the timeout period to the default value.
30
Specifies the timeout period, in seconds.
path-probing
config>test-oam>ldp-treetrace
7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C
Commands in this context configure LDP tree trace path probing.
The validation process for LDP FEC ECMP paths runs in the background to test the LDP ECMP paths discovered by the path discovery capability. The probe used is an LSP Ping message with an IP address drawn from the subrange of 127/8 addresses indicated by the output of the tree discovery for this FEC.
Use the interval command to configure the frequency of running path probes. If an interface is down on the ingress LER that is performing the LDP tree trace, LSP ping probes from the interface are not sent, but the ingress LER node does not raise alarms.
The LSP ping routine updates the content of the MPLS echo request message, specifically the IP address, as soon as the LDP ECMP path discovery phase has output the results of a new computation for the path in question.
interval minutes
no interval
config>test-oam>ldp-treetrace>path-probing
7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C
This command configures the frequency of the LSP Ping messages used to probe the paths of all LDP FECs discovered during LDP tree trace path discovery.
The no form of this command resets the interval to the default value.
1
Specifies the number of minutes to wait between probing all active ECMP paths for each LDP FEC.
timeout timeout
no timeout
config>test-oam>ldp-treetrace>path-probing
7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C
This command configures the maximum amount of time, in minutes, that the node waits for a response after sending an LSP Ping message to probe the path of an LDP FEC before declaring failure. After consecutive failures equal to the value configured for the retry-count command, the node gives up.
The no form of the command resets the timeout period to its default value.
1
Specifies the timeout period, in minutes.
[no] shutdown
config>test-oam>ldp-treetrace
7210 SAS-K 2F6C4T and 7210 SAS-K 3SFP+ 8C
This command suspends the background process running the LDP ECMP OAM tree discovery and path probing features. The configuration is not deleted.
The no form of this command enables the background process.