Using Ping to Monitor Link Connectivity on an MPLS Network
Ping operations can be used to check the connectivity of label distribution protocol (LDP) label switched path (LSPs) that carry IPv4 or IPv6 packets and TE tunnels that carry IPv4 packets.
Prerequisites
Before you start a test, run the lspv mpls-lsp-ping echo enable/lspv mpls-lsp-ping echo enable ipv6 command to enable the device to respond to MPLS echo request/MPLS echo request IPv6 packets.
As NQA is deployed on the main control board of a device, both the initiator and responder of an LSP ping test need to send LSP ping test packets to the main control board for processing. If a large number of packets are sent to the main control board, the CPU usage of the main control board increases, which adversely affects device operation. To prevent this problem, run the lspv mpls-lsp-ping cpu-defend cpu-defend command to set an upper limit for the rate of sending MPLS Echo Request packets to the main control board.
If the MPLS packet length of an NQA test instance is greater than the MTU of a specified MPLS tunnel, MPLS packets fail to pass through the tunnel. To allow the packets to pass through the tunnel, run the fragment enable command to enable MPLS packet fragmentation.
Procedure
- To test the connectivity of an LDP LSP that carries IPv4 packets, run:
ping lsp [ -a source-ip | -c count | -exp exp-value | -h ttl-value | -m interval | -r reply-mode | -s packet-size | -t time-out | -v | -g ] * ip destination-iphost mask-length [ ip-address ] [ nexthop nexthop-address ] [ remote remote-address ]
For example:
<HUAWEI> ping lsp -v ip 3.3.3.3 32 LSP PING FEC: IPV4 PREFIX 3.3.3.3/32 : 100 data bytes, press CTRL_C to break Reply from 3.3.3.3: bytes=100 Sequence=1 time = 4 ms Return Code 3, Subcode 1 Reply from 3.3.3.3: bytes=100 Sequence=2 time = 4 ms Return Code 3, Subcode 1 Reply from 3.3.3.3: bytes=100 Sequence=3 time = 4 ms Return Code 3, Subcode 1 Reply from 3.3.3.3: bytes=100 Sequence=4 time = 4 ms Return Code 3, Subcode 1 Reply from 3.3.3.3: bytes=100 Sequence=5 time = 5 ms Return Code 3, Subcode 1 --- FEC: IPV4 PREFIX 3.3.3.3/32 ping statistics --- 5 packet(s) transmitted 5 packet(s) received 0.00% packet loss round-trip min/avg/max = 4/4/5 ms - To test the connectivity of a TE tunnel (RSVP-TE tunnel, static TE tunnel, or dynamic TE tunnel) that carries IPv4 packets, run:
ping lsp [ -a source-ip | -c count | -exp exp-value | -h ttl-value | -m interval | -r reply-mode | -s packet-size | -t time-out | -v | -g ] * te { tunnelName | ifType ifNum } [ hot-standby | primary ] [ compatible-mode ] | auto-tunnel auto-tunnelname }
For example:
<HUAWEI> ping lsp te Tunnel 1 LSP PING FEC: TE TUNNEL IPV4 SESSION QUERY Tunnel1 : 100 data bytes, press CTRL_C to break Reply from 1.1.1.1: bytes=100 Sequence=1 time = 4 ms Reply from 1.1.1.1: bytes=100 Sequence=2 time = 2 ms Reply from 1.1.1.1: bytes=100 Sequence=3 time = 2 ms Reply from 1.1.1.1: bytes=100 Sequence=4 time = 2 ms Reply from 1.1.1.1: bytes=100 Sequence=5 time = 2 ms --- FEC: RSVP IPV4 SESSION QUERY Tunnel1 ping statistics --- 5 packet(s) transmitted 5 packet(s) received 0.00% packet loss round-trip min/avg/max = 2/2/4 ms - Test SR-MPLS TE IPv4 tunnel connectivity.
To test the connectivity of an SR-MPLS TE tunnel dynamically created, run the ping lsp [ -a source-ip | -c count | -exp exp-value | -h ttl-value | -m interval | -s packet-size | -t time-out | -v | -g ] * segment-routing { { auto-tunnel auto-tunnelname [ version { draft2 | draft4 } ] } } [ remote remote-address ] [ hot-standby | primary ] command and specify auto-tunnelname on the ingress to initiate a ping test to the egress.
<HUAWEI> ping lsp -c 3 segment-routing auto-tunnel Tunnel10 version draft4 LSP PING FEC: AUTO TE TUNNEL IPV4 SESSION QUERY Tunnel10 : 100 data bytes, press CTRL_C to break Reply from 10.1.1.2: bytes=100 Sequence=1 time=11 ms Reply from 10.1.1.2: bytes=100 Sequence=2 time=9 ms Reply from 10.1.1.2: bytes=100 Sequence=3 time=6 ms --- FEC: AUTO TE TUNNEL IPV4 SESSION QUERY Tunnel10 ping statistics --- 3 packet(s) transmitted 3 packet(s) received 0.00% packet loss round-trip min/avg/max = 6/8/11 msTo test the connectivity of an SR-MPLS TE IPv4 tunnel manually configured, run the ping lsp [ -a source-ip | -c count | -exp exp-value | -h ttl-value | -m interval | -s packet-size | -t time-out | -v | -g ] * segment-routing te { tunnelName | ifType ifNum } [ draft2 ] [ remote remote-address ] [ hot-standby | primary ] command to initiate a ping test to the egress.
<HUAWEI> ping lsp -c 3 segment-routing te Tunnel10 LSP PING FEC: TE TUNNEL IPV4 SESSION QUERY Tunnel10 : 100 data bytes, press CTRL_C to break Reply from 10.1.1.2: bytes=100 Sequence=1 time=11 ms Reply from 10.1.1.2: bytes=100 Sequence=2 time=9 ms Reply from 10.1.1.2: bytes=100 Sequence=3 time=6 ms --- FEC: TE TUNNEL IPV4 SESSION QUERY Tunnel10 ping statistics --- 3 packet(s) transmitted 3 packet(s) received 0.00% packet loss round-trip min/avg/max = 6/8/11 ms
- Test SR-MPLS BE IPv4 tunnel connectivity.
To test the connectivity of an SR-MPLS BE IPv4 tunnel, run the ping lsp [ -a source-ip | -c count | -exp exp-value | -h ttl-value | -m interval | -s packet-size | -t time-out | -v | -g ] * segment-routing ip destination-address mask-length [ flex-algo flex-algo-id ] [ version draft2 ] [ bypass ] [ remote remote-ip ] command.
<HUAWEI> ping lsp segment-routing ip 3.3.3.9 32 version draft2 LSP PING FEC: SEGMENT ROUTING IPV4 PREFIX 3.3.3.9/32 : 100 data bytes, press CTRL_C to break Reply from 3.3.3.9: bytes=100 Sequence=1 time=13 ms Reply from 3.3.3.9: bytes=100 Sequence=2 time=9 ms Reply from 3.3.3.9: bytes=100 Sequence=3 time=2 ms Reply from 3.3.3.9: bytes=100 Sequence=4 time=3 ms Reply from 3.3.3.9: bytes=100 Sequence=5 time=6 ms --- FEC: SEGMENT ROUTING IPV4 PREFIX 3.3.3.9/32 ping statistics --- 5 packet(s) transmitted 5 packet(s) received 0.00% packet loss round-trip min/avg/max = 2/6/13 ms - Test the connectivity of a BGP LSP that carries IPv4 packets.
To test the connectivity of a BGP LSP that carries IPv4 packets, run the ping lsp [ -a source-ip | -c count | -exp exp-value | -h ttl-value | -m interval | -r reply-mode | -s packet-size | -t time-out | -v | -g ] * bgp destination-iphost mask-length [ vpn-instance vpn-name ] [ ip-address ] [ nexthop nexthop-address ] command.
<HUAWEI> ping lsp -c 2 bgp 4.4.4.4 32 LSP PING FEC: BGP LABELED IPV4 PREFIX 4.4.4.4/32/ : 100 data bytes, press CTRL_C to break Reply from 4.4.4.4: bytes=100 Sequence=1 time=46 ms Reply from 4.4.4.4: bytes=100 Sequence=2 time=2 ms --- FEC: BGP LABELED IPV4 PREFIX 4.4.4.4/32 ping statistics --- 2 packet(s) transmitted 2 packet(s) received 0.00% packet loss round-trip min/avg/max = 2/24/46 ms - Test the connectivity of an LDP LSP connected with an SR-MPLS BE tunnel.
To test the connectivity of an LDP LSP connected with an SR-MPLS BE tunnel, run the ping lsp [ -a source-ip | -c count | -exp exp-value | -h ttl-value | -m interval | -r reply-mode | -s packet-size | -t time-out | -v | -g ] * ip destination-iphost mask-length [ ip-address ] [ nexthop nexthop-address ] [ remote remote-address ] command on the ingress to initiate a ping test to the egress of the SR-MPLS BE tunnel.
<HUAWEI> ping lsp -c 3 ip 5.5.5.9 32 remote 5.5.5.9 LSP PING FEC: IPV4 PREFIX 5.5.5.9/32/ : 100 data bytes, press CTRL_C to break Reply from 5.5.5.9: bytes=100 Sequence=1 time=3 ms Reply from 5.5.5.9: bytes=100 Sequence=2 time=3 ms Reply from 5.5.5.9: bytes=100 Sequence=3 time=3 ms --- FEC: IPV4 PREFIX 5.5.5.9/32 ping statistics --- 3 packet(s) transmitted 3 packet(s) received 0.00% packet loss round-trip min/avg/max = 3/3/3 ms - Test the connectivity of an SR-MPLS BE tunnel connected with an LDP LSP.To test the connectivity of an SR-MPLS BE tunnel connected with an LDP LSP, run the ping lsp [ -a source-ip | -c count | -exp exp-value | -h ttl-value | -m interval | -s packet-size | -t time-out | -v | -g ] * segment-routing ip destination-address mask-length [ flex-algo flex-algo-id ] [ version draft2 ] [ bypass ] remote remote-ip command on the ingress to initiate a ping test to the egress with the destination address being the LDP LSP.
When testing the connectivity of an SR-MPLS BE tunnel connected with an LDP LSP, specify a remote IP address using the remote remote-ip parameter.
<HUAWEI> ping lsp -c 3 segment-routing ip 5.5.5.9 32 version draft2 remote 5.5.5.9 LSP PING FEC: IPV4 PREFIX 5.5.5.9/32 : 100 data bytes, press CTRL_C to break Reply from 5.5.5.9: bytes=100 Sequence=1 time=9 ms Reply from 5.5.5.9: bytes=100 Sequence=2 time=2 ms Reply from 5.5.5.9: bytes=100 Sequence=3 time=3 ms --- FEC: IPV4 PREFIX 5.5.5.9/32 ping statistics --- 3 packet(s) transmitted 3 packet(s) received 0.00% packet loss round-trip min/avg/max = 2/4/9 ms - Test the connectivity of an LDP LSP connected with an SR-MPLS BE tunnel (the LDP end does not support interworking).
To test the connectivity of an LDP LSP connected with an SR-MPLS BE tunnel, run the ping lsp [ -a source-ip | -c count | -exp exp-value | -h ttl-value | -m interval | -r reply-mode | -s packet-size | -t time-out | -v | -g ] * ip destination-iphost mask-length [ ip-address ] [ nexthop nexthop-address ] [ remote remote-address ] command on the ingress to initiate a ping test to the egress of the SR-MPLS BE tunnel.
You must run the lspv echo-reply fec-validation ldp disable command on the SR-MPLS BE side to disable the LSPV response end from checking the LDP FEC.
<HUAWEI> ping lsp -v ip 3.3.3.3 32 LSP PING FEC: IPV4 PREFIX 3.3.3.3/32 : 100 data bytes, press CTRL_C to break Reply from 3.3.3.3: bytes=100 Sequence=1 time = 4 ms Return Code 3, Subcode 1 Reply from 3.3.3.3: bytes=100 Sequence=2 time = 4 ms Return Code 3, Subcode 1 Reply from 3.3.3.3: bytes=100 Sequence=3 time = 4 ms Return Code 3, Subcode 1 Reply from 3.3.3.3: bytes=100 Sequence=4 time = 4 ms Return Code 3, Subcode 1 Reply from 3.3.3.3: bytes=100 Sequence=5 time = 5 ms Return Code 3, Subcode 1 --- FEC: IPV4 PREFIX 3.3.3.3/32 ping statistics --- 5 packet(s) transmitted 5 packet(s) received 0.00% packet loss round-trip min/avg/max = 4/4/5 ms - Test the connectivity of an SR-MPLS BE tunnel connected with an LDP LSP (the LDP end does not support interworking).
To test the connectivity of an SR-MPLS BE tunnel connected with an LDP LSP, run the ping lsp [ -a source-ip | -c count | -exp exp-value | -h ttl-value | -m interval | -s packet-size | -t time-out | -v | -g ] * segment-routing ip destination-address mask-length [ flex-algo flex-algo-id ] [ version draft2 ] [ bypass ] remote-fec { ldp remoteipaddr remotemasklen | nil } command on the ingress to initiate a ping test to the egress with the destination address being the LDP LSP.
<HUAWEI> ping lsp -c 3 segment-routing ip 5.5.5.9 32 version draft2 remote-fec ldp 5.5.5.9 32 LSP PING FEC: IPV4 PREFIX 5.5.5.9/32 : 100 data bytes, press CTRL_C to break Reply from 5.5.5.9: bytes=100 Sequence=1 time=9 ms Reply from 5.5.5.9: bytes=100 Sequence=2 time=2 ms Reply from 5.5.5.9: bytes=100 Sequence=3 time=3 ms --- FEC: IPV4 PREFIX 5.5.5.9/32 ping statistics --- 3 packet(s) transmitted 3 packet(s) received 0.00% packet loss round-trip min/avg/max = 2/4/9 ms - Test the connectivity of an SR-MPLS TE policy tunnel carrying IPv4 packets.
To test the connectivity of an SR-MPLS TE policy tunnel carrying IPv4 packets, run the ping lsp [ -a source-ip | -c count | -exp exp-value | -h ttl-value | -m interval | -s packet-size | -t time-out | -v | -g ] * sr-te policy { policy-name policyname | endpoint-ip endpoint-ip color colorid | binding-sid bsid } command.
<HUAWEI> ping lsp sr-te policy policy-name test LSP PING FEC: Nil FEC : 100 data bytes, press CTRL_C to break sr-te policy's segment list: Preference : 300; Path Type: main; Protocol-Origin : local; Originator: 0, 0.0.0.0; Discriminator: 300; Segment-List ID : 1; Xcindex : 1 Reply from 3.3.3.9: bytes=100 Sequence=1 time=13 ms Reply from 3.3.3.9: bytes=100 Sequence=2 time=9 ms Reply from 3.3.3.9: bytes=100 Sequence=3 time=2 ms Reply from 3.3.3.9: bytes=100 Sequence=4 time=3 ms Reply from 3.3.3.9: bytes=100 Sequence=5 time=6 ms --- FEC: Nil FEC ping statistics --- 5 packet(s) transmitted 5 packet(s) received 0.00% packet loss round-trip min/avg/max = 2/6/13 ms sr-te policy's segment list: Preference : 400; Path Type: backup; Protocol-Origin : local; Originator: 0, 0.0.0.0; Discriminator: 400; Segment-List ID : 2; Xcindex : 2 Reply from 3.3.3.9: bytes=100 Sequence=1 time=13 ms Reply from 3.3.3.9: bytes=100 Sequence=2 time=9 ms Reply from 3.3.3.9: bytes=100 Sequence=3 time=2 ms Reply from 3.3.3.9: bytes=100 Sequence=4 time=3 ms Reply from 3.3.3.9: bytes=100 Sequence=5 time=6 ms --- FEC: Nil FEC ping statistics --- 5 packet(s) transmitted 5 packet(s) received 0.00% packet loss - Test the connectivity of an inter-AS E2E SR-MPLS TE tunnel.To test the connectivity of an inter-AS E2E SR-MPLS TE tunnel, run the ping lsp [ -a source-ip | -c count | -exp exp-value | -h ttl-value | -m interval | -s packet-size | -t timeout | -v | -g | -r reply-mode ] * segment-routing { { auto-tunnel srAutoTnlName version { draft2 | draft4 } } | te { tunnelName | ifType ifNum } [ draft2 ] } [ remote remoteAddress ] [ hot-standby ] command.
<HUAWEI> ping lsp segment-routing te Tunnel 11 draft2 LSP PING FEC: SEGMENT ROUTING TE TUNNEL IPV4 SESSION QUERY Tunnel11 : 100 data bytes, press CTRL_C to break Reply from 5.5.5.9: bytes=100 Sequence=1 time=14 ms Reply from 5.5.5.9: bytes=100 Sequence=2 time=12 ms Reply from 5.5.5.9: bytes=100 Sequence=3 time=9 ms Reply from 5.5.5.9: bytes=100 Sequence=4 time=11 ms Reply from 5.5.5.9: bytes=100 Sequence=5 time=8 ms --- FEC: SEGMENT ROUTING TE TUNNEL IPV4 SESSION QUERY Tunnel11 ping statistics --- 5 packet(s) transmitted 5 packet(s) received 0.00% packet loss round-trip min/avg/max = 8/10/14 ms
- (Optional) Run the display lspv statistics command to check LSPV packet statistics.
If the test using the ping lsp command fails, you can run this command to check whether the fault occurs on the LSP or the device.
- (Optional) Run the reset lspv statistics command to clear LSPV packet statistics.
Follow-up Procedure
After the test is completed, you are advised to run the undo lspv mpls-lsp-ping echo enable/undo lspv mpls-lsp-ping echo enable ipv6 command to disable the device from responding to MPLS Echo Request/MPLS Echo Request IPv6 packets to prevent system resource occupation.