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标签为 ‘ASR9k’的文章

ASR9k Netflow and QOS order in the inbound direction

My customer match a issue that business traffics take IP6,7 flag, then the traffics auto mapping to EXP6,7 that cause control police congestion, and ISIS flapping due to BFD flap. So they want to check which traffics have incorrect flag by netflow, so need to check ording for netflow and QOS at input direction. I check some documents, nobody notice that, so the article will show test info, you can check if you need. Finaly test result: At ingress direction, packets will be cached first by netflow, then do other action in QOS.

Btw, due to auto mapping from TOS to EXP by range, e.g: TOS 192-223 will map to EXP6; TOS 223-255 will map to EXP7. So if we want to check the issue by netflow, suggest filter EXP data, as in my follow test, check by follow command:

RP/0/RSP1/CPU0:ASR9006-G#sh flow monitor test-mpls cache brief location 0/0/cpu0 | i 7-0
Fri Jan  8 04:57:39.604 UTC
      LDP 44.44.44.44/32        30000-7-0        40034-7-1           -                -                -                -          Te0/0/0/2       Te0/0/0/1       Fwd                  3888         36           Egr 12.1.1.1         55.55.55.55      0xff     icmp     0          2048

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How to convert SPP into text2pcap readable format by python

Introduction

There are some internal tools that can decode SPP packets at former, but they are not work now. In some scenario, customer coudln’t do span on our asr9k, so we only need SPP, then will face to how to decode SPP result.

The article disscuss how to covert SPP original data to text2pcap readable format, then decode by text2pcap. You only do the script that can auto work. Btw, before do that, you need have python2.7 and text2pcap (integrate in wireshark). If you have python3.0 or newer, that maybe have some issue, because some function have a bit different, you need adjust them by yourself.

Solution

Original SPP data:

=~=~=~=~=~=~=~=~=~=~=~= PuTTY log 2017.12.04 17:12:19 =~=~=~=~=~=~=~=~=~=~=~=
trace p stop
Tracing stopped with 666 outstanding...
spp-ui> trace print
Packet serial 861
port4/classify:
  length 148 phys_int_index 0 next_ctx 0xdeadbeef time 09:10:41.407
  00: 00 70 72 00 00 08 00 65 7a 00 00 00 ff ff 00 07 
  10: 80 30 00 00 00 00 0f 00 00 00 1f 00 00 00 00 00 
  20: 00 70 05 f2 42 fb 00 00 04 00 01 40 07 01 05 27 
  30: 06 03 0e 06 00 00 00 00 4c 00 00 00 00 00 58 00 
  40: 00 00 00 00 00 00 06 01 00 a1 13 41 92 60 00 b2 
  50: 64 41 8a 4c 08 00 45 c0 00 3e 00 00 00 00 fe 11 
  60: c8 25 12 ac 79 0d 34 df d0 01 02 86 02 86 00 2a 
  70: 75 5a 00 01 00 1e 3f da a4 0f 00 00 01 00 00 14 
  80: 00 00 00 00 04 00 00 04 00 5a c0 00 04 01 00 04 
  90: 3f da a4 0f 00 00 00 00 00 00 00 00 00 00 00 00 
  a0: 00 00 00 17 00 08 05 01 00 00 af c8 00 24 14 01 
  b0: 01 08 3f da d0 46 20 00 01 08 3f da d0 42 20 00 
  c0: 01 08 3f da d0 41 20 00 01 08 3f da d0 07 20 00 
  d0: 00 08 13 01 00 00 08 00 00 20 cf 07 00 00 07 16 
  e0: 4d 50 4c 53 2d 54 45 20 74 6f 20 76 61 72 30 31 
  f0: 2e 6b 6c 70 30 32 00 00 00 0c 0b 07 3f df 04 08 
--------------------------

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Troubleshooting IPoE Session that pending at “ACK-DPM-WAIT”

Introduction

The article will talk about what is “ACK-DPM-WAIT”, and how to troubleshooting the similar scenario. Due to limitation info that couldn’t narrow down, in my CASE, so will update the article if the issue happen again and find RCA.

Problem Description

Version: 5.1.3 + induvial SMU
Platform: 9010 + Mod80 + A9K-MPA-4X10GE
BNG: IPOE, DHCP Proxy, 28k session

My customer found part of BNG session was failure. Trigger is due to customer power supply have issue that cause the asr9k re-power. After 9k reload, found dhcpd and arp have so many alarms, dhcpd was recovery after tried restart process multi times, but arp continue have SPIO alarm even if tried restart process, customer had enabled arp local disable on the BNG port.

The issue sessions got address correct from DHCP, but session would be deleted after 15min. After checked on asr9k, we found issue session pending on ACK_DPM_WAIT status. And the issue was auto recovery at approx.19:00-19:30. And at that timeslot, arp alarm disappear too.
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Auto check share memory utilization for IOX by Python

Introduction

In some scenario, we need to monitor some data in router/switch by automation. This article will show example that how to check share memory utilization. And you can easy to change the script base on your requirement/scenario.

Prepare

Due to “telnetlib” couldn’t exactly check expect messages by read_until() function (that couldn’t control exactly time when the info return to buffer), so I change to “expect”. And follow Bo’s example Python Expect Demo, and there is a good documents for expect demo from IBM too: 探索 Pexpect,第 2 部分:Pexpect 的实例分析
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Do action by EEM+TCL after the log happen X Times in Y LC/RSP at ASR9k

Problem:

We can do more automated action by EEM + TCL on Cisco router, and have more trigger way for syslog pattern trigger, OID trigger, CPU Threshold trigger and so on. That will match IOS platform, no any issue. But in XR platform, each LC/RSP have separate alarm, we maybe have special requirement, e.g:

Some alarms frequency happen, I want to restart the process (base on pid) if the alarm happen 3 times in 5min on each LC, how to do that?

0/3/cpu0: alarm report "C", Pid = zzz
0/1/cpu0: alarm report "A", Pid = xxx
0/2/cpu0: alarm report "B", pid = yyy
0/3/cpu0: alarm report "C", pid = zzz
0/1/cpu0: alarm report "A", pid = xxx
0/1/cpu0: alarm report "A", pid = xxx

Solution:

We can do interactive script by TCL I/O, create a file in Harddisk/disk which has the history/count of syslog for Lcs. We can read this file using the script whenever the syslog is observed. Based on the number of syslogs the script can take the required action.

The steps will be like this, please check attachment and script flow chart for detail script, in my example, I only dump arp process for testing, please change script base on your requirement, in order to test script, you can add flag to test that, e.g “action_syslog priority info msg “a””: 完整阅读