The following operating guidelines apply to lsp-ping and lsp-trace:
The sender node builds the target FEC stack TLV with a single FEC element corresponding to the destination node SID of the SR-ISIS or SR-OSPF tunnel.
A node SID label swapped at the LSR results in return code 8, ‟Label switched at stack-depth <RSC>” in accordance with RFC 4379.
A node SID label that is popped at the LSR results in return code 3, ‟Replying router is an egress for the FEC at stack-depth <RSC>”.
The lsp-trace command is supported with the inclusion of the DSMAP TLV, the DDMAP TLV, or none. If none is configured, no map TLV is sent. The downstream interface information is returned, along with the egress label for the node SID tunnel and the protocol that resolved the node SID at the responder node.
The following figure shows a sample topology for an lsp-ping and lsp-trace for SR-ISIS node SID tunnels.
Example
Given this topology, the following output is an example of LSP-PING on DUT-A for target node SID on DUT-F.
*A:Dut-A# oam lsp-ping sr-isis prefix 10.20.1.6/32 igp-instance 0 detail
LSP-PING 10.20.1.6/32: 80 bytes MPLS payload
Seq=1, send from intf int_to_B, reply from 10.20.1.6
udp-data-len=32 ttl=255 rtt=3.2ms rc=3 (EgressRtr)
---- LSP 10.20.1.6/32 PING Statistics ----
1 packets sent, 1 packets received, 0.00% packet loss
round-trip min = 3.2ms, avg = 3.2ms, max = 3.2ms, stddev = 0.000ms
Example
The following output is an example of LSP-TRACE on DUT-A for target node SID on DUT-F (DSMAP TLV).
*A:Dut-A# oam lsp-trace sr-isis prefix 10.20.1.6/32 igp-instance 0 detail
lsp-trace to 10.20.1.6/32: 0 hops min, 0 hops max, 108 byte packets
1 10.20.1.2 rtt=2.29ms rc=8(DSRtrMatchLabel) rsc=1
DS 1: ipaddr=10.10.4.4 ifaddr=10.10.4.4 iftype=ipv4Numbered MRU=1496
label[1]=26406 protocol=6(ISIS)
2 10.20.1.4 rtt=3.74ms rc=8(DSRtrMatchLabel) rsc=1
DS 1: ipaddr=10.10.9.6 ifaddr=10.10.9.6 iftype=ipv4Numbered MRU=1496
label[1]=26606 protocol=6(ISIS)
3 10.20.1.6 rtt=4.97ms rc=3(EgressRtr) rsc=1
Example
The following output is an example of LSP-TRACE on DUT-A for target node SID on DUT-F (DDMAP TLV).
*A:Dut-A# oam lsp-trace sr-isis prefix 10.20.1.6/32 igp-instance 0 downstream-map-
tlv ddmap detail
lsp-trace to 10.20.1.6/32: 0 hops min, 0 hops max, 108 byte packets
1 10.20.1.2 rtt=2.56ms rc=8(DSRtrMatchLabel) rsc=1
DS 1: ipaddr=10.10.4.4 ifaddr=10.10.4.4 iftype=ipv4Numbered MRU=1496
label[1]=26406 protocol=6(ISIS)
2 10.20.1.4 rtt=3.59ms rc=8(DSRtrMatchLabel) rsc=1
DS 1: ipaddr=10.10.9.6 ifaddr=10.10.9.6 iftype=ipv4Numbered MRU=1496
label[1]=26606 protocol=6(ISIS)
3 10.20.1.6 rtt=5.00ms rc=3(EgressRtr) rsc=1