Introduction
This document describes how to capture Point-to-Point Packet over Ethernet (PPPoE) packet on an ingress interface of ASR1000 box.
Prerequisites
Requirements
Cisco recommends that you meet these requirements before you attempt this configuration:
- Layer 1 connectivity between ASR1k and the client router is up
Components Used
This document is restricted to XE version 3.13 and above.
PPPoE Server - ASR1006
PPPoE Client - Any Cisco Router
The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command.
Background
This document help a techinician to determine if PPPoE packets are actually hitting the interface of the ASR1k router acting as a PPPoE Server. This is usefull in scenarios where we troubleshoot PPPoE failures.
Configure
Note: Use the Command Lookup Tool (registered customers only) in order to obtain more information on the commands used in this section.
Configuration on the ASR1006 that acts as a Server
A sample of the configuration on ASR1006 that acts as a server is shown here:
interface GigabitEthernet0/0/2 >>>> Interface connecting towards the PPPoE Client
no ip address
negotiation auto
pppoe enable group global
cdp enable
bba-group pppoe global
virtual-template 1
interface Virtual-Template1
ip unnumbered Loopback0
peer default ip address pool test
ppp authentication chap
end
interface Loopback0
ip address 10.1.1.1 255.255.255.255
end
Capturing PPPoE packet on ASR1006
Enable below commands on exec prompt of the ASR1006 router:
ASR# debug platform condition interface GigabitEthernet0/0/2 ingress
ASR# debug platform packet-trace packet 256 fia-trace
ASR# debug platform condition start
ASR# debug platform packet-trace enable
Initiate PPPoE session from the PPPoE Client
ASR# show platform packet-trace summary
ASR# show platform packet-trace summary
Pkt Input Output State Reason
0 Gi0/0/2 internal0/0/rp:0 PUNT 3 (Layer2 control and legacy)
1 Gi0/0/2 internal0/0/rp:0 PUNT 27 (Subscriber session control)
2 Gi0/0/2 internal0/0/rp:0 PUNT 27 (Subscriber session control)
3 Gi0/0/2 internal0/0/rp:0 PUNT 27 (Subscriber session control)
4 Gi0/0/2 internal0/0/rp:0 PUNT 27 (Subscriber session control)
5 Gi0/0/2 internal0/0/rp:0 PUNT 27 (Subscriber session control)
6 Gi0/0/2 internal0/0/rp:0 PUNT 27 (Subscriber session control)
7 Gi0/0/2 internal0/0/rp:0 PUNT 27 (Subscriber session control)
8 Gi0/0/2 internal0/0/rp:0 PUNT 27 (Subscriber session control)
Now we can check a specific packet above using:
ASR# show platform packet-trace packet 8
Packet: 8 CBUG ID: 8
Summary
Input : GigabitEthernet0/0/2
Output : internal0/0/rp:0
State : PUNT 27 (Subscriber session control
Timestamp
Start : 1732092767453258 ns (11/25/2015 09:27:01.520615 UTC)
Stop : 1732092767494466 ns (11/25/2015 09:27:01.520656 UTC)
Path Trace
Feature: FIA_TRACE
Entry : 0x802655e0 - PPPOE_GET_SESSION
Lapsed time: 2493 ns
Feature: FIA_TRACE
Entry : 0x805ce9e4 - ESS_ENTER_SWITCHING
Lapsed time: 1293 ns
The above packet shows that PPPoE packets are hitting the interface.
You can disable the packet tracer as below:
ASR# no debug platform condition interface GigabitEthernet0/0/2 ingress
ASR# no debug platform packet-trace packet 256 fia-trace
ASR# debug platform condition stop
ASR# no debug platform packet-trace enable
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