CISCO 1000 Series Software Configuration IOS XE 17 Packet Trace User Guide

CISCO 1000 Series Software Configuration IOS XE 17 Packet Trace

Specifications

• First Published: August 03, 2016

Product Information

The Packet-Trace feature provides a detailed understanding of how data packets are processed by the Cisco IOS XE platform, and thus helps customers to diagnose issues and troubleshoot them more efficiently. It offers three levels of inspection for packets:  accounting, summary, and path data. Each level provides a detailed view of packet processing at the cost of some packet processing] capability. Packet Trace limits inspection to packets that match the debug platform condition statements and is a viable option even under heavy-traffic situations in customer environments.

Packet Trace

First Published: August 03, 2016

• The Packet-Trace feature provides a detailed understanding of how data packets are processed by the Cisco IOS XE platform, and thus helps customers to diagnose issues and troubleshoot them more efficiently. This module provides information about how to use the Packet-Trace feature.
• Information About Packet Trace, on page 1
• Usage Guidelines for Configuring Packet Trace, on page 2
• Configuring Packet Trace, on page 2
• Displaying Packet-Trace Information, on page 7
• Removing Packet-Trace Data, on page 7
• Configuration Examples for Packet Trace , on page 7
• Additional References, on page 20
• Feature Information for Packet Trace, on page 20

Information About Packet Trace

• The Packet-Trace feature provides three levels of inspection for packets: accounting, summary, and path data. Each level provides a detailed view of packet processing at the cost of some packet processing capability. However, Packet Trace limits inspection to packets that match the debug platform condition statements, and is a viable option even under heavy-traffic situations in customer environments.
• The following table explains the three levels of inspection provided by packet trace.

Table 1: Packet-Trace Level

leave the network processor. Packet-Trace accounting is a lightweight performance activity, and runs continuously until it is disabled.
Summary| At the summary level of packet trace, data is collected for a finite number of packets. Packet-Trace summary tracks the input and output interfaces, the final packet state, and punt, drop, or inject packets, if any. Collecting summary data adds to additional performance compared to normal packet processing, and can help to isolate a troublesome interface.
Packet-Trace Level| Description
---|---
Path data|

• The packet-trace path data level provides the greatest level of detail in packet trace. Data is collected for a finite number of packets. Packet-Trace path data captures data, including a conditional debugging ID that is useful to correlate with feature debugs, a timestamp, and also feature-specific path-trace data.
• Path data also has two optional capabilities: packet copy and Feature Invocation Array (FIA) trace. The packet-copy option enables you to copy input and output packets at various layers of the packet (layer 2, layer 3 or layer 4). The FIA- trace option tracks every feature entry invoked during packet processing and helps you to know what is happening during packet processing.

Note Collecting path data consumes more packet-processing resources, and the optional capabilities incrementally affect packet performance. Therefore, path-data level should be used in limited capacity or in situations where packet performance change is acceptable.

Usage Guidelines for Configuring Packet Trace

Consider the following best practices while configuring the Packet-Trace feature

• Use of ingress conditions when using the Packet-Trace feature is recommended for a more comprehensive view of packets.
• Packet-trace configuration requires data-plane memory. On systems where data-plane memory is constrained, carefully consider how you will select the packet-trace values. A close approximation of the amount of memory consumed by packet trace is provided by the following equation:
• memory required = (statistics overhead) + number of packets * (summary size + data size + packet copy size).
• When the Packet-Trace feature is enabled, a small, fixed amount of memory is allocated for statistics. Similarly, when per-packet data is captured, a small, fixed amount of memory is required for each packet for summary data. However, as shown by the equation, you can significantly influence the amount of memory consumed by the number of packets you select to trace, and whether you collect path data and copies of packets.

Configuring Packet Trace

Perform the following steps to configure the Packet-Trace feature.

Note

• The amount of memory consumed by the Packet-Trace feature is affected by the packet-trace configuration. You should carefully select the size of per-packet path data and copy buffers and the number of packets to be traced in order to avoid interrupting normal services. You can check the current data-plane DRAM memory consumption by using the show platform hardware qfp active infrastructure exome statistics command.

Procedure

| Command or Action| Purpose
---|---|---
Step 1| enable

Example Router> enable

| Enables the privileged EXEC mode. Enter your password if prompted.
Step 2| debug platform packet-trace packet pkt-num

[fia-trace | summary-only] [circular] [data-size data-size ]

Example: Router# debug platform packet-trace packets 2048 summary-only

| Collects summary data for a specified number of packets. Captures feature path data by default, and optionally performs FIA trace.

pkt-num —Specifies the maximum number of packets maintained at a given time.

fia-trace —Provides detailed level of data capture, including summary data,

feature-specific data. Also displays each feature entry visited during packet processing.

summary-only —Enables the capture of summary data with minimal details.

circular —Saves the data of the most recently traced packets.

data-size —Specifies the size of data buffers for storing feature and FIA trace data for each packet in bytes. When very heavy packet processing is performed on packets, users can increase the size of the data buffers if necessary. The default value is 2048.

Step 3| debug platform packet-trace {punt

|inject|copy|drop|packet|statistics}

Example: Router# debug platform packet-trace punt

| Enables tracing of punted packets from data to control plane.
Step 4| debug platform condition [ipv4 | ipv6] [interface interface ][access-list access-list

-name | ipv4-address / subnet-mask |

ipv6-address / subnet-mask ] [ingress | egress

|both] Example: Router# debug platform condition interface g0/0/0 ingress

| Specifies the matching criteria for tracing packets. Provides the ability to filter by protocol, IP address and subnet mask, access control list (ACL), interface, and direction.
Step 5| debug platform condition start

Example: Router# debug platform condition start

| Enables the specified matching criteria and starts packet tracing.
| Command or Action| Purpose
---|---|---
Step 6| debug platform condition stop

Example Router# debug platform condition start

| Deactivates the condition and stops packet tracing.
Step 7| show platform packet-trace {configuration

| statistics | summary | packet {all | pkt-num }}

Example

Router# show platform packet-trace 14

| Displays packet-trace data according to the specified option. See {start cross reference} Table 21-1 {end cross reference} for detailed information about the show command options.
Step 8| clear platform condition all

Example: Router(config)# clear platform condition all

| Removes the configurations provided by the debug platform condition and debug platform packet-trace commands.
Step 9| exit Example: Router# exit| Exits the privileged EXEC mode.

Configuring Packet Tracer with UDF Offset

Perform the following steps to configure the Packet-Trace UDF with offset

Procedure

| Command or Action| Purpose
---|---|---
Step 1| enable

Example: Device> enable

| Enables privileged EXEC mode.

• Enter your password if prompted.

Step 2| configure terminal

Example: Device# configure terminal

| Enters global configuration mode.
Step 3| udf udf name header { inner | outer } { 13|14 }

offset offset-in-bytes length length-in-bytes

Example: Router(config)# udf TEST_UDF_NAME_1 header inner l3 64 1

| Configures individual UDF definitions. You can specify the name of the UDF, the networking header from which offset, and the length of data to be extracted.

The inner or outer keywords indicate the start of the offset from the unencapsulated Layer 3 or Layer 4 headers, or if there is an

| Command or Action| Purpose
---|---|---
| ****

Router(config)# udf TEST_UDF_NAME_2 header inner l4 77 2

Router(config)# udf TEST_UDF_NAME_3 header outer l3 65 1

Router(config)# udf TEST_UDF_NAME_4 header outer l4 67 1

| encapsulated packet, they indicate the start of offset from the inner L3/L4.

The length keyword specifies, in bytes, the length from the offset. The range is from 1 to 2.

Step 4| udf udf name { header | packet-start } offset-base offset length

Example: Router(config)# udf TEST_UDF_NAME_5 packet-start 120 1

|

• header—Specifies the offset base configuration.
• packet-start—Specifies the offset base from packet-start. packet-start” can vary depending on if packet-trace is for an inbound packet or outbound packet. If the packet-trace is for an inbound packet then the packet-start will be layer2. For outbound, he packet-start will be layer3.
• offset—Specifies the number of bytes offset from the offset base. To match the first byte from the offset base (Layer 3/Layer 4 header), configure the offset as 0
• length—Specifies the number of bytes from the offset. Only 1 or 2 bytes are supported. To match additional bytes, you must define multiple UDFs.

Step 5| ip access-list extended { acl-name | acl-num }

Example:

Router(config)# ip access-list extended acl2

| Enables extended ACL configuration mode. The CLI enters the extended ACL configuration mode in which all subsequent commands apply to the current extended access list. Extended ACLs control traffic by the comparison of the source and destination addresses of the IP packets to the addresses configured in the ACL.
Step 6| ip access-list extended { deny | permit } udfudf-name value mask

Example: Router(config-acl)# permit ip any any udf TEST_UDF_NAME_5 0xD3 0xFF

| Configures the ACL to match on UDFs along with the current access control entries (ACEs)

• The bytes defined in ACL is 0xD3. Masks are used with IP addresses in IP ACLs to specify what should be permitted and denied.

Step 7| debug platform condition [ipv4 | ipv6] [ interface interface ] [access-list access-list name | ipv4-address / subnet-mask || Specifies the matching criteria for tracing packets. Provides the ability to filter by protocol, IP address and subnet mask, access control list (ACL), interface, and direction.
| Command or Action| Purpose
---|---|---
| ipv6-address / subnet-mask ] [ ingress | egress |both ]

Example: Router# debug platform condition interface gi0/0/0 ipv4 access- list acl2

both

|
Step 8| debug platform condition start

Example: Router# debug platform condition start

| Enables the specified matching criteria and starts packet tracing.
Step 9| debug platform packet-trace packet pkt-num [ fia-trace | summary-only] [ circular ] [ data-size data-size ]

Example: Router# debug platform packet-trace packet 1024 fia-trace data- size 2048

| Collects summary data for a specified number of packets. Captures feature path data by default, and optionally performs FIA trace.

pkt-num —Specifies the maximum number of packets maintained at a given time.

fia-trace —Provides detailed level of data capture, including summary data,

feature-specific data. Also displays each feature entry visited during packet processing.

summary-only —Enables the capture of summary data with minimal details.

circular —Saves the data of the most recently traced packets.

data-size —Specifies the size of data buffers for storing feature and FIA trace data for each packet in bytes. When very heavy packet processing is performed on packets, users can increase the size of the data buffers if necessary. The default value is 2048.

Step 10| debug platform packet-trace {punt | inject|copy | drop |packet | statistics}

Example Router# debug platform packet-trace punt

| Enables tracing of punted packets from data to control plane.
Step 11| debug platform condition stop

Example: Router# debug platform condition start

| Deactivates the condition and stops packet tracing.
Step 12| exit Example:| Exits the privileged EXEC mode.
| Command or Action| Purpose
---|---|---
| Router# exit|

Displaying Packet-Trace Information

Use these show commands to display packet-trace information.
Table 2: show Commands

configuration, including any defaults.
show platform packet-trace statistics| Displays accounting data for all the traced packets.
show platform packet-trace summary| Displays summary data for the number of packets specified.
show platform packet-trace {all | pkt-num } [decode]| Displays the path data for all the packets or the packet specified. The decode option attempts to decode the binary packet into a more human- readable form.

Removing Packet-Trace Data

Use these commands to clear packet-trace data.
Table 3: clear Commands

trace data and statistics.
clear platform packet-trace configuration| Clears the packet-trace configuration and the statistics

Configuration Examples for Packet Trace

This section provides the following configuration examples:

Example: Configuring Packet Trace

• This example describes how to configure packet trace and display the results. In this example, incoming packets to Gigabit Ethernet interface 0/0/1 are traced, and FIA-trace data is captured for the first 128 packets. Also, the input packets are copied. The show platform packet-trace packet 0 command displays the summary data and each feature entry visited during packet processing for packet 0.

enable

• Router# debug platform packet-trace packet 128 fia-trace Router# debug platform packet-trace punt
• Router# debug platform condition interface g0/0/1 ingress Router# debug platform condition start
• Router#! ping to UUT
• Router# debug platform condition stop
• Router# show platform packet-trace packet 0
• Packet: 0 CBUG ID: 9

Summary

• Input : GigabitEthernet0/0/1
• Output : GigabitEthernet0/0/0
• State : FWD

Timestamp

• Start : 1819281992118 ns (05/17/2014 06:42:01.207240 UTC)
• Stop : 1819282095121 ns (05/17/2014 06:42:01.207343 UTC)

Path Trace

• Feature: IPV4
• Source : 192.0.2.1
• Destination : 192.0.2.2
• Protocol : 1 (ICMP)
• Feature: FIA_TRACE
• Entry : 0x8059dbe8 – DEBUG_COND_INPUT_PKT
• Timestamp : 3685243309297
• Feature: FIA_TRACE
• Entry : 0x82011a00 – IPV4_INPUT_DST_LOOKUP_CONSUME
• Timestamp : 3685243311450
• Feature: FIA_TRACE
• Entry : 0x82000170 – IPV4_INPUT_FOR_US_MARTIAN
• Timestamp : 3685243312427
• Feature: FIA_TRACE
• Entry : 0x82004b68 – IPV4_OUTPUT_LOOKUP_PROCESS
• Timestamp : 3685243313230
• Feature: FIA_TRACE
• Entry : 0x8034f210 – IPV4_INPUT_IPOPTIONS_PROCESS
• Timestamp : 3685243315033
• Feature: FIA_TRACE
• Entry : 0x82013200 – IPV4_OUTPUT_GOTO_OUTPUT_FEATURE
• Timestamp : 3685243315787
• Feature: FIA_TRACE
• Entry : 0x80321450 – IPV4_VFR_REFRAG
• Timestamp : 3685243316980
• Feature: FIA_TRACE
• Entry : 0x82014700 – IPV6_INPUT_L2_REWRITE
• Timestamp : 3685243317713
• Feature: FIA_TRACE
• Entry : 0x82000080 – IPV4_OUTPUT_FRAG
• Timestamp : 3685243319223
• Feature: FIA_TRACE
• Entry : 0x8200e500 – IPV4_OUTPUT_DROP_POLICY
• Timestamp : 3685243319950
• Feature: FIA_TRACE
• Entry : 0x8059aff4 – PACTRAC_OUTPUT_STATS
• Timestamp : 3685243323603
• Feature: FIA_TRACE
• Entry : 0x82016100 – MARMOT_SPA_D_TRANSMIT_PKT
• Timestamp : 3685243326183
• Router# clear platform condition all
• Router# exit

Linux Forwarding Transport Service (LFTS) is a transport mechanism to forward packets punted from the CPP into applications other than IOSd. This example displays the LFTS-based intercepted packet destined for binos application

• Router# show platform packet-trace packet 10
• Packet: 10 CBUG ID: 52

Summary

• Input : GigabitEthernet0/0/0
• Output : internal0/0/rp:1
• State : PUNT 55 (For-us control)

Timestamp

• Start : 597718358383 ns (06/06/2016 09:00:13.643341 UTC)
• Stop : 597718409650 ns (06/06/2016 09:00:13.643392 UTC)
• Path Trace
• Feature: IPV4
• Input : GigabitEthernet0/0/0
• Output :
• Source : 10.64.68.2
• Destination : 10.0.0.102
• Protocol : 17 (UDP)
• SrcPort : 1985
• DstPort : 1985
• Feature: FIA_TRACE
• Input : GigabitEthernet0/0/0
• Output :
• Entry : 0x8a0177bc – DEBUG_COND_INPUT_PKT
• Lapsed time : 426 ns
• Feature: FIA_TRACE
• Input : GigabitEthernet0/0/0
• Output :
• Entry : 0x8a017788 – IPV4_INPUT_DST_LOOKUP_CONSUME
• Lapsed time : 386 ns
• Feature: FIA_TRACE
• Input : GigabitEthernet0/0/0
• Output :
• Entry : 0x8a01778c – IPV4_INPUT_FOR_US_MARTIAN
• Lapsed time : 13653 ns
• Feature: FIA_TRACE
• Input : GigabitEthernet0/0/0
• Output : internal0/0/rp:1
• Entry : 0x8a017730 – IPV4_INPUT_LOOKUP_PROCESS_EXT
• Lapsed time : 2360 ns
• Feature: FIA_TRACE
• Input : GigabitEthernet0/0/0
• Output : internal0/0/rp:1
• Entry : 0x8a017be0 – IPV4_INPUT_IPOPTIONS_PROCESS_EXT
• Lapsed time : 66 ns
• Feature: FIA_TRACE
• Input : GigabitEthernet0/0/0
• Output : internal0/0/rp:1
• Entry : 0x8a017bfc – IPV4_INPUT_GOTO_OUTPUT_FEATURE_EXT
• Lapsed time : 680 ns
• Feature: FIA_TRACE
• Input : GigabitEthernet0/0/0
• Output : internal0/0/rp:1
• Entry : 0x8a017d60 – IPV4_INTERNAL_ARL_SANITY_EXT
• Lapsed time : 320 ns
• Feature: FIA_TRACE
• Input : GigabitEthernet0/0/0
• Output : internal0/0/rp:1
• Entry : 0x8a017a40 – IPV4_VFR_REFRAG_EXT
• Lapsed time : 106 ns
• Feature: FIA_TRACE
• Input : GigabitEthernet0/0/0
• Output : internal0/0/rp:1
• Entry : 0x8a017d2c – IPV4_OUTPUT_DROP_POLICY_EXT
• Lapsed time : 1173 ns
• Feature: FIA_TRACE
• Input : GigabitEthernet0/0/0
• Output : internal0/0/rp:1
• Entry : 0x8a017940 – INTERNAL_TRANSMIT_PKT_EXT
• Lapsed time : 20173 ns
• LFTS Path Flow: Packet: 10 CBUG ID: 52
• Feature: LFTS
• Pkt Direction: IN
• Punt Cause : 55
• subCause : 0

Example: Using Packet Trace

• This example provides a scenario in which packet trace is used to troubleshoot packet drops for a NAT configuration on a Cisco device. This example shows how you can effectively utilize the level of detail provided by the Packet-Trace feature to gather information about an issue, isolate the issue, and then find a solution.
• In this scenario, you can detect that there are issues, but are not sure where to start troubleshooting. You should, therefore, consider accessing the Packet-Trace summary for a number of incoming packets.
• Router# debug platform condition ingress
• Router# debug platform packet-trace packet 2048 summary-only
• Router# debug platform condition start
• Router# debug platform condition stop
• Router# show platform packet-trace summary
• Pkt Input Output State Reason
• 0 Gi0/0/0 Gi0/0/0 DROP 402 (NoStatsUpdate)

1.  internal0/0/rp:0 internal0/0/rp:0 PUNT 21 (RP<->QFP keepalive)
2. internal0/0/recycle:0 Gi0/0/0 FWD

The output shows that packets are dropped due to NAT configuration on Gigabit Ethernet interface 0/0/0, which enables you to understand that an issue is occurring on a specific interface. Using this information, you can limit which packets to trace, reduce the number of packets for data capture, and increase the level of inspection.

• Router# debug platform packet-trace packet 256
• Router# debug platform packet-trace punt
• Router# debug platform condition interface Gi0/0/0
• Router# debug platform condition start
• Router# debug platform condition stop
• Router# show platform packet-trace summary
• Router# show platform packet-trace 15
• Packet: 15 CBUG ID: 238

Summary

• Input : GigabitEthernet0/0/0
• Output : internal0/0/rp:1
• State : PUNT 55 (For-us control)

Timestamp

• Start : 1166288346725 ns (06/06/2016 09:09:42.202734 UTC)
• Stop : 1166288383210 ns (06/06/2016 09:09:42.202770 UTC)
• Path Trace
• Feature: IPV4
• Input : GigabitEthernet0/0/0
• Output :
• Source : 10.64.68.3
• Destination : 10.0.0.102
• Protocol : 17 (UDP)
• SrcPort : 1985
• DstPort : 1985
• IOSd Path Flow: Packet: 15 CBUG ID: 238
• Feature: INFRA
• Pkt Direction: IN
• Packet Rcvd From CPP
• Feature: IP
• Pkt Direction: IN
• Source : 10.64.68.122
• Destination : 10.64.68.255
• Feature: IP
• Pkt Direction: IN
• Packet Enqueued in IP layer
• Source : 10.64.68.122
• Destination : 10.64.68.255
• Interface : GigabitEthernet0/0/0
• Feature: UDP
• Pkt Direction: IN
• src : 10.64.68.122(1053)
• dst : 10.64.68.255(1947)
• length : 48
• Router#show platform packet-trace packet 10
• Packet: 10 CBUG ID: 10

Summary

• Input : GigabitEthernet0/0/0
• Output : internal0/0/rp:0
• State : PUNT 55 (For-us control)

Timestamp

• Start : 274777907351 ns (01/10/2020 10:56:47.918494 UTC)
• Stop : 274777922664 ns (01/10/2020 10:56:47.918509 UTC)
• Path Trace
• Feature: IPV4(Input)
• Input : GigabitEthernet0/0/0
• Output :
• Source : 10.78.106.2
• Destination : 10.0.0.102
• Protocol : 17 (UDP)
• SrcPort : 1985
• DstPort : 1985
• IOSd Path Flow: Packet: 10 CBUG ID: 10
• Feature: INFRA
• Pkt Direction: IN
• Packet Rcvd From DATAPLANE
• Feature: IP
• Pkt Direction: IN
• Packet Enqueued in IP layer
• Source : 10.78.106.2
• Destination : 10.0.0.102
• Interface : GigabitEthernet0/0/0
• Feature: UDP
• Pkt Direction: IN DROP
• Pkt : DROPPED
• UDP: Discarding silently
• src : 881 10.78.106.2(1985)
• dst : 10.0.0.102(1985)
• length : 60
• Router#show platform packet-trace packet 12
• Packet: 12 CBUG ID: 767

Summary

• Input : GigabitEthernet3
• Output : internal0/0/rp:0
• State : PUNT 11 (For-us data)

Timestamp

• Start : 16120990774814 ns (01/20/2020 12:38:02.816435 UTC)
• Stop : 16120990801840 ns (01/20/2020 12:38:02.816462 UTC)
• Path Trace
• Feature: IPV4(Input)
• Input : GigabitEthernet3
• Output :
• Source : 10.1.1.1
• Destination : 10.1.1.2
• Protocol : 6 (TCP)
• SrcPort : 46593
• DstPort : 23
• IOSd Path Flow: Packet: 12 CBUG ID: 767
• Feature: INFRA
• Pkt Direction: IN
• Packet Rcvd From DATAPLANE
• Feature: IP
• Pkt Direction: IN
• Packet Enqueued in IP layer
• Source : 10.1.1.1
• Destination : 10.1.1.2
• Interface : GigabitEthernet3
• Feature: IP
• Pkt Direction: IN
• FORWARDEDTo transport layer
• Source : 10.1.1.1
• Destination : 10.1.1.2
• Interface : GigabitEthernet3
• Feature: TCP
• Pkt Direction: IN
• tcp0: I NoTCB 10.1.1.1:46593 10.1.1.2:23 seq 1925377975 OPTS 4 SYN WIN 4128

Router# show platform packet-trace summary Pkt Input Output State Reason

INJ.2 Gi1 FWD

1. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
2. INJ.2 Gi1 FWD
3. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
4. NJ.2 Gi1 FWD
5. NJ.2 Gi1 FWD
6. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
7. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
8. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
9. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
10. INJ.2 Gi1 FWD
11. INJ.2 Gi1 FWD
12. INJ.2 Gi1 FWD
13. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
14. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
15. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
16. INJ.2 Gi1 FWD

The following example displays the packet trace data statistics.

• Router#show platform packet-trace statistics
• Packets Summary
• Matched 3
• Traced 3
• Packets Received
• Ingress 0
• Inject 0
• Packets Processed
• Forward 0
• Punt 3
• Count Code Cause
• 3 56 RP injected for-us control
• Drop 0
• Consume 0
• PKT_DIR_IN
• Dropped Consumed Forwarded
• INFRA 0 0 0
• TCP 0 0 0
• UDP 0 0 0
• IP 0 0 0
• IPV6 0 0 0
• ARP 0 0 0
• PKT_DIR_OUT
• Dropped Consumed Forwarded
• INFRA 0 0 0
• TCP 0 0 0
• UDP 0 0 0
• IP 0 0 0
• IPV6 0 0 0
• ARP 0 0 0

The following example displays packets that are injected and punted to the forwarding processor from the control plane.

• Router#debug platform condition ipv4 10.118.74.53/32 both
• Router#Router#debug platform condition start
• Router#debug platform packet-trace packet 200
• Packet count rounded up from 200 to 256
• Router#show platform packet-tracer packet 0
• show plat pack pa 0
• Packet: 0 CBUG ID: 674

Summary

• Input : GigabitEthernet1
• Output : internal0/0/rp:0
• State : PUNT 11 (For-us data)

Timestamp

• Start : 17756544435656 ns (06/29/2020 18:19:17.326313 UTC)
• Stop : 17756544469451 ns (06/29/2020 18:19:17.326346 UTC)
• Path Trace
• Feature: IPV4(Input)
• Input : GigabitEthernet1
• Output :
• Source : 10.118.74.53
• Destination : 172.18.124.38
• Protocol : 17 (UDP)
• SrcPort : 2640
• DstPort : 500
• IOSd Path Flow: Packet: 0 CBUG ID: 674
• Feature: INFRA
• Pkt Direction: IN
• Packet Rcvd From DATAPLANE
• Feature: IP
• Pkt Direction: IN
• Packet Enqueued in IP layer
• Source : 10.118.74.53
• Destination : 172.18.124.38
• Interface : GigabitEthernet1
• Feature: IP
• Pkt Direction: IN
• FORWARDED To transport layer
• Source : 10.118.74.53
• Destination : 172.18.124.38
• Interface : GigabitEthernet1
• Feature: UDP
• Pkt Direction: IN

DROPPED

• UDP: Checksum error: dropping
• Source : 10.118.74.53(2640)
• Destination : 172.18.124.38(500)
• Router#show platform packet-tracer packet 2
• Packet: 2 CBUG ID: 2
• IOSd Path Flow:
• Feature: TCP
• Pkt Direction: OUTtcp0: O SYNRCVD 172.18.124.38:22 172.18.124.55:52774 seq 3052140910
• OPTS 4 ACK 2346709419 SYN WIN 4128
• Feature: TCP
• Pkt Direction: OUT

FORWARDED

• TCP: Connection is in SYNRCVD state
• ACK : 2346709419
• SEQ : 3052140910
• Source : 172.18.124.38(22)
• Destination : 172.18.124.55(52774)
• Feature: IP
• Pkt Direction: OUTRoute out the generated packet.srcaddr: 172.18.124.38, dstaddr:
• 172.18.124.55
• Feature: IP
• Pkt Direction: OUTInject and forward successful srcaddr: 172.18.124.38, dstaddr:
• 172.18.124.55
• Feature: TCP
• Pkt Direction: OUTtcp0: O SYNRCVD 172.18.124.38:22 172.18.124.55:52774 seq 3052140910
• OPTS 4 ACK 2346709419 SYN WIN 4128

Summary

• Input : INJ.2
• Output : GigabitEthernet1
• State : FWD

Timestamp

• Start : 490928006866 ns (06/29/2020 13:31:30.807879 UTC)
• Stop : 490928038567 ns (06/29/2020 13:31:30.807911 UTC)
• Path Trace
• Feature: IPV4(Input)
• Input : internal0/0/rp:0
• Output :
• Source : 172.18.124.38
• Destination : 172.18.124.55
• Protocol : 6 (TCP)
• SrcPort : 22
• DstPort : 52774
• Feature: IPSec
• Result : IPSEC_RESULT_DENY
• Action : SEND_CLEAR
• SA Handle : 0
• Peer Addr : 10.124.18.172
• Local Addr: 10.124.18.172

Example: Using Packet Trace

• This example provides a scenario in which packet trace is used to troubleshoot packet drops for a NAT configuration on a Cisco ASR 1006 Router. This example shows how you can effectively utilize the level of detail provided by the Packet-Trace feature to gather information about an issue, isolate the issue, and then find a solution.
• In this scenario, you can detect that there are issues, but are not sure where to start troubleshooting. You should, therefore, consider accessing the Packet-Trace summary for a number of incoming packets.
• Router# debug platform condition ingress
• Router# debug platform packet-trace packet 2048 summary-only
• Router# debug platform condition start
• Router# debug platform condition stop
• Router# show platform packet-trace summary

Pkt Input Output State Reason
0 Gi0/0/0 Gi0/0/0 DROP 402 (NoStatsUpdate)

1. internal0/0/rp:0 internal0/0/rp:0 PUNT 21 (RP<->QFP keepalive)
2. internal0/0/recycle:0 Gi0/0/0 FWD

• The output shows that packets are dropped due to NAT configuration on Gigabit Ethernet interface 0/0/0, which enables you to understand that an issue is occurring on a specific interface. Using this information, you can limit which packets to trace, reduce the number
• of packets for data capture, and increase the level of= inspection.
• Router# debug platform packet-trace packet 256
• Router# debug platform packet-trace punt
• Router# debug platform condition interface Gi0/0/0
• Router# debug platform condition start
• Router# debug platform condition stop
• Router# show platform packet-trace summary
• Router# show platform packet-trace 15
• Packet: 15 CBUG ID: 238

Summary

• Input : GigabitEthernet0/0/0
• Output : internal0/0/rp:1
• State : PUNT 55 (For-us control)

Timestamp

• Start : 1166288346725 ns (06/06/2016 09:09:42.202734 UTC)
• Stop : 1166288383210 ns (06/06/2016 09:09:42.202770 UTC)

Path Trace

• Feature: IPV4
• Input : GigabitEthernet0/0/0
• Output :
• Source : 10.64.68.3
• Destination : 224.0.0.102
• Protocol : 17 (UDP)
• SrcPort : 1985
• DstPort : 1985
• IOSd Path Flow: Packet: 15 CBUG ID: 238
• Feature: INFRA
• Pkt Direction: IN
• Packet Rcvd From CPP
• eature: IP
• Pkt Direction: IN
• Source : 10.64.68.122
• Destination : 10.64.68.255
• Feature: IP
• Pkt Direction: IN
• Packet Enqueued in IP layer
• Source : 10.64.68.122
• Destination : 10.64.68.255
• Interface : GigabitEthernet0/0/0
• Feature: UDP
• Pkt Direction: IN
• src : 10.64.68.122(1053)
• dst : 10.64.68.255(1947)
• length : 48
• Router#show platform packet-trace packet 10
• Packet: 10 CBUG ID: 10

Summary

• Input : GigabitEthernet0/0/0
• Output : internal0/0/rp:0
• State : PUNT 55 (For-us control)

Timestamp

• Start : 274777907351 ns (01/10/2020 10:56:47.918494 UTC)
• Stop : 274777922664 ns (01/10/2020 10:56:47.918509 UTC)

Path Trace

• Feature: IPV4(Input)
• Input : GigabitEthernet0/0/0
• Output :
• Source : 10.78.106.2
• Destination : 224.0.0.102
• Protocol : 17 (UDP)
• SrcPort : 1985
• DstPort : 1985
• IOSd Path Flow: Packet: 10 CBUG ID: 10
• Feature: INFRA
• Pkt Direction: IN
• Packet Rcvd From DATAPLANE
• Feature: IP
• Pkt Direction: IN
• Packet Enqueued in IP layer
• Source : 10.78.106.2
• Destination : 224.0.0.102
• Interface : GigabitEthernet0/0/0
• Feature: UDP
• Pkt Direction: IN DROP
• Pkt : DROPPED
• UDP: Discarding silently
• src : 881 10.78.106.2(1985)
• dst : 224.0.0.102(1985)
• length : 60
• Router#show platform packet-trace packet 12
• Packet: 12 CBUG ID: 767

Summary

• Input : GigabitEthernet3
• Output : internal0/0/rp:0
• State : PUNT 11 (For-us data)

Timestamp

• Start : 16120990774814 ns (01/20/2020 12:38:02.816435 UTC)

• Stop : 16120990801840 ns (01/20/2020 12:38:02.816462 UTC)

• Feature: IPV4(Input)

• Input : GigabitEthernet3

• Output :

• Source : 12.1.1.1

• Destination : 12.1.1.2

• Protocol : 6 (TCP)

• SrcPort : 46593

• DstPort : 23

• IOSd Path Flow: Packet: 12 CBUG ID: 767

• Feature: INFRA

• Pkt Direction: IN

• Packet Rcvd From DATAPLANE

• Feature: IP

• Pkt Direction: IN

• Packet Enqueued in IP layer

• Source : 12.1.1.1

• Destination : 12.1.1.2

• Interface : GigabitEthernet3

• Feature: IP

• Pkt Direction: IN

• FORWARDEDTo transport layer

• Source : 12.1.1.1

• Destination : 12.1.1.2

• Interface : GigabitEthernet3

• Feature: TCP

• Pkt Direction: IN

• tcp0: I NoTCB 12.1.1.1:46593 12.1.1.2:23 seq 1925377975 OPTS 4 SYN WIN 4128

Router# show platform packet-trace summaryPkt Input Output State Reason 0 INJ.2 Gi1 FWD

1. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
2.  INJ.2 Gi1 FWD
3. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
4. INJ.2 Gi1 FWD
5. INJ.2 Gi1 FWD
6. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
7. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
8. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
9. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
10. INJ.2 Gi1 FWD
11. NJ.2 Gi1 FWD
12. INJ.2 Gi1 FWD
13. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
14. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
15. Gi1 internal0/0/rp:0 PUNT 11 (For-us data)
16. INJ.2 Gi1 FWD

The following example displays the packet trace data statistics. Router#show platform packet-trace statistics

Packets Summary

• Matched 3
• Traced 3
• Packets Received
• Ingress 0
• Inject 0
• Packets Processed
• Forward 0
• Punt 3
• Count Code Cause
• 3 56 RP injected for-us control
• Drop 0
• Consume 0
• PKT_DIR_IN
• Dropped Consumed Forwarded
• INFRA 0 0 0
• TCP 0 0 0
• UDP 0 0 0
• IP 0 0 0
• IPV6 0 0 0
• ARP 0 0 0
• PKT_DIR_OUT
• Dropped Consumed Forwarded
• INFRA 0 0 0
• TCP 0 0 0
• UDP 0 0 0
• IP 0 0 0
• IPV6 0 0 0
• ARP 0 0 0
• The following example displays packets that are injected and punted to the forwarding processor from the control plane.
• Router#debug platform condition ipv4 10.118.74.53/32 both
• Router#Router#debug platform condition start
• Router#debug platform packet-trace packet 200
• Packet count rounded up from 200 to 256
• Router#show platform packet-tracer packet 0
• show plat pack pa 0
• Packet: 0 CBUG ID: 674

Summary

• Input : GigabitEthernet1
• Output : internal0/0/rp:0
• State : PUNT 11 (For-us data)

Timestamp

• Start : 17756544435656 ns (06/29/2020 18:19:17.326313 UTC)
• Stop : 17756544469451 ns (06/29/2020 18:19:17.326346 UTC)
• Path Trace
• Feature: IPV4(Input)
• Input : GigabitEthernet1
• Output :
• Source : 10.118.74.53
• Destination : 198.51.100.38
• Protocol : 17 (UDP)
• SrcPort : 2640
• DstPort : 500
• IOSd Path Flow: Packet: 0 CBUG ID: 674
• Feature: INFRA
• Pkt Direction: IN
• Packet Rcvd From DATAPLANE
• Feature: IP
• Pkt Direction: IN
• Packet Enqueued in IP layer
• Source : 10.118.74.53
• Destination : 198.51.100.38
• Interface : GigabitEthernet1
• Feature: IP
• Pkt Direction: IN
• FORWARDED To transport layer
• Source : 10.118.74.53
• Destination : 198.51.100.38
• Interface : GigabitEthernet1
• Feature: UDP
• Pkt Direction: IN

DROPPED

• UDP: Checksum error: dropping
• Source : 10.118.74.53(2640)
• Destination : 198.51.100.38(500)
• Router#show platform packet-tracer packet 2
• Packet: 2 CBUG ID: 2
• IOSd Path Flow:
• Feature: TCP
• Pkt Direction: OUTtcp0: O SYNRCVD 198.51.100.38:22 198.51.100.55:52774 seq 3052140910
• OPTS 4 ACK 2346709419 SYN WIN 4128
• Feature: TCP
• Pkt Direction: OUT

FORWARDED

• TCP: Connection is in SYNRCVD state
• ACK : 2346709419
• SEQ : 3052140910
• Source : 198.51.100.38(22)
• Destination : 198.51.100.55(52774)
• Feature: IP
• Pkt Direction: OUTRoute out the generated packet.srcaddr: 198.51.100.38, dstaddr:
• 198.51.100.55
• Feature: IP
• Pkt Direction: OUTInject and forward successful srcaddr: 198.51.100.38, dstaddr:
• 198.51.100.55
• Feature: TCP
• Pkt Direction: OUTtcp0: O SYNRCVD 198.51.100.38:22 198.51.100.55:52774 seq 3052140910
• OPTS 4 ACK 2346709419 SYN WIN 4128

Summary

• Input : INJ.2
• Output : GigabitEthernet1
• State : FWD

Timestamp

• Start : 490928006866 ns (06/29/2020 13:31:30.807879 UTC)
• Stop : 490928038567 ns (06/29/2020 13:31:30.807911 UTC)
• Path Trace
• Feature: IPV4(Input)
• Input : internal0/0/rp:0
• Output :
• Source : 172.18.124.38
• Destination : 172.18.124.55
• Protocol : 6 (TCP)
• SrcPort : 22
• DstPort : 52774
• Feature: IPSec
• Result : IPSEC_RESULT_DENY
• Action : SEND_CLEAR
• SA Handle : 0
• Peer Addr : 55.124.18.172
• Local Addr: 38.124.18.172

Additional References

Standards

MIBs

and feature sets, use Cisco MIB Locator found at this URL:

{start hypertext}http://www.cisco.com/go/mibs{end hypertext}

RFCs

Technical Assistance

The Cisco Support and Documentation website provides online resources to download documentation, software, and tools. Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password.| {start hypertext}http://www.cisco.com/cisco/web/support/index.html{end hypertext}

Feature Information for Packet Trace

• {start cross reference}Table 21-4{end cross reference} lists the features in this module and provides links to specific configuration information.
• Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to{start hypertext} http://www.cisco.com/go/cfn{endhypertext}. An account on Cisco.com is not required.
• {start cross reference}Table 21-4{end cross reference} lists only the software releases that support a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.

Table 4: Feature Information for Packet Trace

information about how data packets are processed by the Cisco IOS XE software.

In Cisco IOS XE Release 3.10S, this feature was introduced. The following commands were introduced or modified:

• debug platform packet-trace packet pkt-num [ fia-trace | summary-only ] [ data-size data-size ] [ circular ]

• debug platform packet-trace copy packet { input | output | both } [ size num-bytes ] [ L2 | L3 | L4 ]

• show platform packet-trace { configuration | statistics | summary packet { all | pkt-num }}

Cisco IOS XE 3.11S|

• In Cisco IOS XE Release 3.11S, this feature was enhanced to include the following features: Matched versus traced statistics.
• Trace stop timestamp in addition to trace start timestamp. The following commands were introduced or modified:
• debug platform packet-trace drop [ code drop-num ]
• show platform packet-trace packet { all | pkt-num } [ decode ]

Cisco IOS XE Denali 16.3.1| In Cisco IOS XE Denali 16.3.1, this feature was enhanced to include Layer3 packet tracing along with IOSd.

The following commands were introduced or modified: debug platform packet- trace punt.

| Cisco IOS XE Amsterdam 17.3.1| The output of the show platform packet- trace command now includes additional trace information for packets either originated from IOSd or destined to IOSd or other BinOS processes.

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