2017-12-31 Log

Comment

大晦日だ。
今年もいろんなことがあって疲れた。
ひきこもってだらり。
気が向けば勉強。
だいたいアニメ。
良いお年を。

Health

ひきこもり

  1. Distance: 0km
  2. Steps: 0

CCIE R&S Today’s study topic

私の学習のチラシの裏。

Introduction to Cisco Equipment

手元にラボ環境構築してやっと進捗した。
GNS3 2.1.1 だけど微妙に動きが怪しい。
1.5.4 のほうがいいのだろうか。。

  1. Ciscoデバイスの操作 – CDP(Cisco Discovery neighbors)
  2. WIP: Ciscoデバイスの操作 – Telnet

CDP(Cisco Discovery Protocol)

CCIE R&S candidate の作業ログ。

CDP(Cisco Discovery Protocol)

トポロジは昨日と一緒。

R2#sh cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
                  S - Switch, H - Host, I - IGMP, r - Repeater

Device ID        Local Intrfce     Holdtme    Capability  Platform  Port ID
R3               Fas 0/0            153         R S I     3725      Fas 0/1
R1               Fas 0/1            153         R S I     3725      Fas 0/0
R2#sh ver | inc IOS
Cisco IOS Software, 3700 Software (C3725-ADVENTERPRISEK9-M), Version 12.4(15)T14, RELEASE SOFTWARE (fc2)
R2#sh cdp neigh detail
-------------------------
Device ID: R3
Entry address(es):
  IP address: 192.168.23.3
Platform: Cisco 3725,  Capabilities: Router Switch IGMP
Interface: FastEthernet0/0,  Port ID (outgoing port): FastEthernet0/1
Holdtime : 179 sec

Version :
Cisco IOS Software, 3700 Software (C3725-ADVENTERPRISEK9-M), Version 12.4(15)T14, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2010 by Cisco Systems, Inc.
Compiled Tue 17-Aug-10 12:08 by prod_rel_team

advertisement version: 2
VTP Management Domain: ''
Duplex: half

デバイスのバージョン

R2(config)#no cdp run

R2#sh run | inc cdp
no cdp log mismatch duplex
no cdp run
R1(config)#no cdp run

特定のインターフェース(スタブネットワークで PC、サーバー等が接続される側)にはこういう無効化設定をすることが多いっぽい。
無駄にトラフィックを消費するので喋らせる意味もない。
さらにはインターネット側に面するインターフェースにCDPを無効にする。
IOS のバージョンからプラットフォームまでバレるのでセキュリティ上の理由からである。

R1(config)#cdp run
R1(config)#int f1/0
R1(config-if)#no cdp enable

別に CDP のフレームを観測するデバイスは Cisco のデバイスである必要はなく、 CDP フレームを解釈できるものであれば(Wireshark等)まるわかりである。

Wireshark で覗き見(合法)。

cdp

でフィルタをかけている。

イーサネットフレームの送信元と宛先を確認してみる。

宛先アドレスは I/G ビットが立っているのでマルチキャストMACアドレスとなっている。
送信元はユニキャストMACアドレス。

読める、読めるぞ!

R1#sh cdp
Global CDP information:
    Sending CDP packets every 30 seconds
    Sending a holdtime value of 90 seconds
    Sending CDPv2 advertisements is  enabled
R1#sh cdp interface f0/0
FastEthernet0/0 is up, line protocol is up
  Encapsulation ARPA
  Sending CDP packets every 30 seconds
  Holdtime is 90 seconds
R1#sh cdp interface f1/0

R1#
R2#sh cdp neigh
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
                  S - Switch, H - Host, I - IGMP, r - Repeater

Device ID        Local Intrfce     Holdtme    Capability  Platform  Port ID
R3               Fas 0/0            178         R S I     3725      Fas 0/1
R1               Fas 0/1            72          R S I     3725      Fas 0/0

cdp table のクリア

R2#clear cdp table
R2#sh cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
                  S - Switch, H - Host, I - IGMP, r - Repeater

Device ID        Local Intrfce     Holdtme    Capability  Platform  Port ID
R2#

特定のエントリの詳細のみ表示。

R2#show cdp entry ?
  *     all CDP neighbor entries
  WORD  Name of CDP neighbor entry

R2#show cdp entry R1
-------------------------
Device ID: R1
Entry address(es):
  IP address: 192.168.12.1
Platform: Cisco 3725,  Capabilities: Router Switch IGMP
Interface: FastEthernet0/1,  Port ID (outgoing port): FastEthernet0/0
Holdtime : 74 sec

Version :
Cisco IOS Software, 3700 Software (C3725-ADVENTERPRISEK9-M), Version 12.4(15)T14, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2010 by Cisco Systems, Inc.
Compiled Tue 17-Aug-10 12:08 by prod_rel_team

advertisement version: 2
VTP Management Domain: ''
Duplex: half

CDP のトラフィック統計情報を見る。
CDP version 2 のパケットのみ送受信している。

R2#sh cdp traffic
CDP counters :
    Total packets output: 812, Input: 681
    Hdr syntax: 0, Chksum error: 0, Encaps failed: 0
    No memory: 0, Invalid packet: 0, Fragmented: 0
    CDP version 1 advertisements output: 0, Input: 0
    CDP version 2 advertisements output: 812, Input: 681

CDP 統計情報をリセットする

R2#clear cdp counters
R2#sh cdp traffic
CDP counters :
    Total packets output: 0, Input: 0
    Hdr syntax: 0, Chksum error: 0, Encaps failed: 0
    No memory: 0, Invalid packet: 0, Fragmented: 0
    CDP version 1 advertisements output: 0, Input: 0
    CDP version 2 advertisements output: 0, Input: 0

ちなみに CDP に相当する LLDP が IEEE802.1AB で標準化されたマルチベンダの Layer 2 プロトコル。
Link Layer Discovery Protocol

遠くにあるデバイスの接続インターフェースもわかるし便利だね。

References

  1. Ciscoデバイスの操作 – CDP(Cisco Discovery neighbors)

2017-12-30 Log

Comment

昨日はずっと死んだように寝ていた。
今日は実家に帰省した。
溜まっていた勉強をやり始めた。

Health

  1. Distance: 4.9km
  2. Steps: 6,995

CCIE R&S Today’s study topic

私の学習のチラシの裏。

Introduction to Cisco Equipment

手元にラボ環境構築してやっと進捗した。
GNS3 2.1.1 だけど微妙に動きが怪しい。
1.5.4 のほうがいいのだろうか。。

  1. Ciscoデバイスの操作 – Cisco IOSネットワーク診断ツール ping, trace, debug
  2. WIP: Ciscoデバイスの操作 – CDP(Cisco Discovery neighbors)

CCIE R&S Official Cert Guide Library v5.0

Vol 1

  1. Basic Switch Port Configuration
  2. WIP: Ethernet Layer 2: Framing and Addressing
    • I/Gビット、U/Lビット

Lab

WIP: Cisco Press Ex.1-1 Lab: Manual configuration of the speed and duplex

Done.
実機での長い旅だった。。。
作業ログはここに・・・

Cisco Press CCIE R&S v5 Ex.1-1 Lab: Manual configuration of the speed and duplex | | Beyond Future Yak Shaving

Today’s Yak Shaving

dump

ヤフオクで落札した Cisco Catalyst スイッチにパスワードがかかったままだったので初期化した | | Beyond Future Yak Shaving

Will

  1. nokogiri web scraping

ヤフオクで落札した Cisco Catalyst スイッチにパスワードがかかったままだったので初期化した

先日来から実機検証していて特定のプラットフォーム依存ぽい例を検証するために Catalyst 2950 をヤフオクで落札しました。
いつものようにコンソールケーブルつないでスイッチの起動してログイン、 en, sh ver あたり入力できたら評価しておわりと思っていたんですが、今回は勝手が違いました。

Switch>en
Password:
Password:
Password:
% Bad secrets

イネーブルシークレットが設定されている。。。。(しかもどっかのコンフィグが残ったままと思しきホスト名)
見なかったことにしてさっそくコンフィグの初期化に取り掛かります。
まずはモードボタンを押し続けると。

C2950 Boot Loader (C2950-HBOOT-M) Version 12.1(11r)EA1, RELEASE SOFTWARE (fc1)
Compiled Mon 22-Jul-02 17:18 by antonino
WS-C2950SX-24 starting...
Base ethernet MAC Address: 00:19:2f:fc:ac:c0
Xmodem file system is available.

The system has been interrupted prior to initializing the
flash filesystem.  The following commands will initialize
the flash filesystem, and finish loading the operating
system software:

    flash_init
    load_helper
    boot

switch: flash_init
Initializing Flash...
flashfs[0]: 4 files, 1 directories
flashfs[0]: 0 orphaned files, 0 orphaned directories
flashfs[0]: Total bytes: 7741440
flashfs[0]: Bytes used: 3140608
flashfs[0]: Bytes available: 4600832
flashfs[0]: flashfs fsck took 5 seconds.
...done initializing flash.
Boot Sector Filesystem (bs:) installed, fsid: 3
Parameter Block Filesystem (pb:) installed, fsid: 4
switch: load_helper
switch: dir flash:
Directory of flash:/

2    -rwx  3132298   <date>               c2950-i6q4l2-mz.121-22.EA13.bin
3    -rwx  77        <date>               private-config.text
5    -rwx  5002      <date>               config.text
6    -rwx  1048      <date>               multiple-fs

4600832 bytes available (3140608 bytes used)

Ciscoデバイスの管理 – Catalystスイッチ – パスワードリカバリー

switch: rename flash: config.text flash:config.text.old
Unknown cmd: rme
switch: rename flash: config.text flash
Unknown cmd: rename
switch: config
Unknown cmd: config
switch: rename flash: config.text flash: config.text.old
usage: rename <old_name> <new_name>
switch: rename flash:config.text flash:config.text.old

switch: boot
Loading "flash:/c2950-i6q4l2-mz.121-22.EA13.bin"...#############################
#########################################################

(snip)

POST: System Board Test : Passed
POST: Ethernet Controller Test : Passed
ASIC Initialization Passed

POST: FRONT-END LOOPBACK TEST : Passedcisco WS-C2950SX-24 (RC32300) processor (revision M0) with 20957K bytes of memory.
Processor board ID FOC1037Z1E9
Last reset from system-reset
Running Standard Image
24 FastEthernet/IEEE 802.3 interface(s)
2 Gigabit Ethernet/IEEE 802.3 interface(s)

32K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address: 00:19:2F:FC:AC:C0
Motherboard assembly number: 73-8135-08
Power supply part number: 34-0965-01
Motherboard serial number: FOC10341U7G
Power supply serial number: DTH10274Z6H
Model revision number: M0
Motherboard revision number: A0
Model number: WS-C2950SX-24
System serial number: FOC1037Z1E9

         --- System Configuration Dialog ---

Would you like to enter the initial configuration dialog? [yes/no]:
00:00:13: %SPANTREE-5-EXTENDED_SYSID: Extended SysId enabled for type vlan
00:00:17: %SYS-5-RESTART: System restarted --
Cisco Internetwork Operating System Software
IOS (tm) C2950 Software (C2950-I6Q4L2-M), Version 12.1(22)EA13, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2009 by cisco Systems, Inc.
Compiled Fri 27-Feb-09 22:20 by amvarma
00:00:17: %SNMP-5-COLDSTART: SNMP agent on host Switch is undergoing a cold start
% Please answer 'yes' or 'no'.
Would you like to enter the initial configuration dialog? [yes/no]: no



Press RETURN to get started!


00:00:40: %LINK-5-CHANGED: Interface Vlan1, changed state to administratively down

起動した・・・

Switch>en
Switch#rename flash:config.text.old flash:config.text
Destination filename [config.text]?
Switch#copy flash:config.text system:running-config
Destination filename [running-config]?
5002 bytes copied in 2.752 secs (1818 bytes/sec)
Switch#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
Switch(config)#no enable secret

Switch(config)#^Z
Switch#
*Mar  1 00:11:41.065: %SYS-5-CONFIG_I: Configured from console by console
Switch(config)#no enable password

ブート時のメッセージを見てみる。

00:00:13: %SPANTREE-5-EXTENDED_SYSID: Extended SysId enabled for type vlan
*Mar  1 00:00:18.055: %SYS-5-CONFIG_I: Configured from memory by console
*Mar  1 00:00:18.244: %SYS-5-RESTART: System restarted --
Cisco Internetwork Operating System Software
IOS (tm) C2950 Software (C2950-I6Q4L2-M), Version 12.1(22)EA13, RELEASE SOFTWARE
 (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2009 by cisco Systems, Inc.
Compiled Fri 27-Feb-09 22:20 by amvarma
*Mar  1 00:00:18.244: %SNMP-5-COLDSTART: SNMP agent on host Switch is undergoin
g a cold start Switch Switch Configuration Script V.4.0.0 / Switch_SX-TC-24.cfg
Switch>

Catalystスイッチ – boot system flashコマンド

Switch#show boot
BOOT path-list:
Config file:          flash:/config.text
Private Config file:  flash:/private-config.text
Enable Break:         no
Manual Boot:          no
HELPER path-list:
NVRAM/Config file
      buffer size:    32768
Timeout for Config
          Download:    0 seconds
Config Download
       via DHCP:       disabled (next boot: disabled)

Switch#copy running-config startup-config
Destination filename [startup-config]?
Building configuration...
[OK]

今回は設定ファイルは消して工場出荷時に戻したかったので

erase startup-config
reload

です。

[confirm]
[OK]
Erase of nvram: complete
Switch#reloa
*Mar  1 00:01:41.537: %SYS-7-NV_BLOCK_INIT: Initalized the geometry of nvramd
Proceed with reload? [confirm]

*Mar  1 00:01:50.221: %SYS-5-RELOAD: Reload requested by console. Reload Reason: Reload Command.

本当にありがとうございました。

Cisco Press CCIE R&S v5 Ex.1-1 Lab: Manual configuration of the speed and duplex

Cisco Press CCIE R&S v5 Ex.1-1 の提示されたサンプルを実際に試してみたら意外と大変だったという話。
やっぱり実機検証はいろいろと勉強になるなというもの。

この例はオートネゴシエーションを使わずに手動のデュプレックス、速度を設定する例で、片方を全二重で、もう一方を半二重にしてどうなるかというもの。
CDP ではデュプレックスの不一致として警告が表示される。

途中で実機を変更してやったのでスイッチ間のインタフェース番号が f0/3 から f0/13 になってます。
予め該当するインタフェースは no shut しておく。

ASW1#sh int f0/3
FastEthernet0/3 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0022.bd89.2183 (bia 0022.bd89.2183)
  MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, media type is 10/100BaseTX
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:08, output 00:00:01, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     174 packets input, 20631 bytes, 0 no buffer
     Received 86 broadcasts (86 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 86 multicast, 0 pause input
     0 input packets with dribble condition detected

speed -> duplex の順に設定する。
duplex を先に設定しようとすると reject される。
とのこと。

ASW1(config-if)#duplex half
ASW1(config-if)#
*Mar  1 00:22:33.250: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/3, changed state t
o down
ASW1(config-if)#
*Mar  1 00:22:35.255: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEthernet0/3, changed state t
o up

コマンド入ったやんけ。。。

ASW1(config-if)#do sh int f0/3
FastEthernet0/3 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0022.bd89.2183 (bia 0022.bd89.2183)
  MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Half-duplex, 100Mb/s, media type is 10/100BaseTX
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:06, output 00:00:01, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     281 packets input, 33916 bytes, 0 no buffer
     Received 144 broadcasts (144 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 144 multicast, 0 pause input
     0 input packets with dribble condition detected

ちなみに IOS 15 系の Catalyst 2960 系

IOS 12 系の話か??

クロスケーブルとストレートケーブルがごっちゃになってて面倒。
まあ、Catalyst スイッチはだいたい Auto MDI/MDI-X やってくれるんだけどね。

ちなみにルータ同士はちゃんとクロスで接続しないとリンクアップしない。
物理レベルでは up してるけど L2 レベルではリンクアップしていないのがわかる。

Catalyst 2940 を引っ張り出してくる。

R2#sh int f0/1
FastEthernet0/1 is up, line protocol is down
  Hardware is Gt96k FE, address is 0024.c431.126f (bia 0024.c431.126f)
  MTU 1500 bytes, BW 100000 Kbit/sec, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Auto-duplex, Auto Speed, 100BaseTX/FX
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:01:25, output 00:01:26, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     5 packets input, 1690 bytes
     Received 5 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog
     0 input packets with dribble condition detected
     20 packets output, 2330 bytes, 0 underruns

IOS 12 でも duplex コマンド先に入ったんだけど、、、

本当は以下のエラーが表示される。

Duplex will not be set until speed is set to non-auto value

原典にあたる。

  1. イーサネット 10/100/1000 Mbps 半二重/全二重自動ネゴシエーションの設定とトラブルシューティング – Cisco
  2. Tutorial: Cisco Catalyst 3560 Switch Interfaces Configuration – Cisco & Cisco Network Hardware News and Technology

今使ってるスイッチ

  1. Catalyst 2940 IOS 12
  2. Catalyst 2960 IOS 15
  3. Catalyst 3750 IOS 15

このセクションで説明するコマンドは、次のタイプのスイッチ製品に適用されます。 Cisco IOS システム ソフトウェア(スーパーバイザ エンジン III)が稼働する Catalyst 2900XL、3500XL、2950、3550、2948G-L3、4908G-L3、Catalyst 4500/4000 スイッチ製品、および Cisco IOS システム ソフトウェアが稼働する Catalyst 6500/6000 スイッチ製品

型番違う。
つまり再現できないじゃん。
そういうこととして覚えとくしか無いんか。。。
プラットフォーム依存。

output, collision の表記もない。
なんなんや・・・

54 output errors, 5 collisions, 0 interface resets
0 babbles, 54 late collision, 59 deferred

このへん激しいトラフィックが無いとコリジョン起こさないからだめなのかな・・・

ASW2#sh int f0/3
FastEthernet0/3 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0026.ca6b.e983 (bia 0026.ca6b.e983)
  MTU 1500 bytes, BW 10000 Kbit/sec, DLY 1000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Half-duplex, 10Mb/s, media type is 10/100BaseTX
  input flow-control is off, output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:01, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 3000 bits/sec, 2 packets/sec
     34467 packets input, 2590785 bytes, 0 no buffer
     Received 28785 broadcasts (28784 multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 28784 multicast, 0 pause input
     0 input packets with dribble condition detected

IOS 12 系でもそんな出力はない。

Switch#sh int f0/1
FastEthernet0/1 is down, line protocol is down (notconnect)
  Hardware is Fast Ethernet, address is 0012.7f15.d881 (bia 0012.7f15.d881)
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Half-duplex, Auto-speed, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 01:45:28, output 01:45:29, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     26737 packets input, 2148098 bytes, 0 no buffer
     Received 22650 broadcasts (0 multicast)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 22650 multicast, 0 pause input
     0 input packets with dribble condition detected
     67480 packets output, 4791532 bytes, 0 underruns

なんなんや・・・

Solved: Catalyst 3850 high Total output drops a… – Cisco Support Community

あんま重要でもないのかなこのトピックは。

もっかい原典あさる。
今度は検索は cisco.com 直指定。英語のドキュメントのみ探す。

site:cisco.com Duplex will not be set until speed is set to non-auto value
  1. Configuring and Troubleshooting Ethernet 10/100/1000Mb Half/Full Duplex Auto-Negotiation

!— Error: On this platform, you must set the speed before the duplex.
!— Not all switch platforms have this command ordering requirement.

プラットフォーム依存だよとのこと。そういうことかよ・・・

日本語は have this command で尻切れトンボで終わってるので絶対原文読んだほうがいい。

Cisco Press の原著読む場合でも CCO (っていうのかな?)を合わせて調べるのは必須ということやな・・。

  1. Cisco.com (CCO) に登録しよう:ネットワークエンジニアになろう!
  2. CCIE R&S CCO (cisco.com) 公式ドキュメント
  3. Select Your Product or Technology – Product/Technology Support – Cisco Systems

残りの検証内容は

双方向の大量のトラフィックを流して確認

Solved: CRC Errors on Cat 2950 – Cisco Support Community

1週間後ぐらいの追試。
ヤフオクで Catalyst 2950 2台落札してやりました。

本当は以下の項目も表示してほしい

54 output errors, 5 collisions, 0 interface resets
0 babbles, 54 late collision, 59 deferred

Switch#sh ver
Cisco Internetwork Operating System Software
IOS (tm) C2950 Software (C2950-I6Q4L2-M), Version 12.1(22)EA13, RELEASE SOFTWARE
 (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2009 by cisco Systems, Inc.
Compiled Fri 27-Feb-09 22:20 by amvarma
Image text-base: 0x80010000, data-base: 0x80570000

ROM: Bootstrap program is C2950 boot loader

Switch uptime is 10 minutes
System returned to ROM by power-on
System image file is "flash:/c2950-i6q4l2-mz.121-22.EA13.bin"

cisco WS-C2950SX-24 (RC32300) processor (revision M0) with 20957K bytes of memory.
Processor board ID FOC1037Z1E9
Last reset from system-reset
Running Standard Image
24 FastEthernet/IEEE 802.3 interface(s)
2 Gigabit Ethernet/IEEE 802.3 interface(s)

32K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address: 00:19:2F:FC:AC:C0
Motherboard assembly number: 73-8135-08
Power supply part number: 34-0965-01
Motherboard serial number: FOC10341U7G
Power supply serial number: DTH10274Z6H
Model revision number: M0
Motherboard revision number: A0
Model number: WS-C2950SX-24
System serial number: FOC1037Z1E9
Configuration register is 0xF

Catalyst 2950 で確認

duplex を先に投入すると本当は以下のエラーが表示される。

Duplex will not be set until speed is set to non-auto value

こんなものは表示されない。
IOS のバージョンが上がって直った(?)のだろうか。
手持ちの実機で正直この挙動に出会った例がない。
キリがないのでこれ以上の深追いはしないことにする。

sh int の出力の確認

Switch#sh int f0/1
FastEthernet0/1 is down, line protocol is down (notconnect)
  Hardware is Fast Ethernet, address is 0019.2ffc.acc1 (bia 0019.2ffc.acc1)
  MTU 1500 bytes, BW 10000 Kbit, DLY 1000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Half-duplex, Auto-speed, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input never, output 00:09:53, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts (0 multicast)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     0 packets output, 0 bytes, 0 underruns
     0 output errors, 0 collisions, 2 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

Catalyst 2950 でデュプレックス不一致による挙動の確認

FDX

ASW201#sh int f0/13
FastEthernet0/13 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0019.2ffc.accd (bia 0019.2ffc.accd)
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 251/255, txload 57/255, rxload 12/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:05, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 4949000 bits/sec, 809 packets/sec
  5 minute output rate 22638000 bits/sec, 2060 packets/sec
     411676 packets input, 332699284 bytes, 0 no buffer
     Received 7072 broadcasts (6309 multicast)
     0 runts, 21 giants, 0 throttles
     9003 input errors, 8982 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 6309 multicast, 0 pause input
     0 input packets with dribble condition detected
     2811088 packets output, 4106529108 bytes, 0 underruns
     0 output errors, 0 collisions, 2 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

HDX

ASW202#sh int f0/13
FastEthernet0/13 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0017.5a3a.7c0d (bia 0017.5a3a.7c0d)
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 251/255, txload 9/255, rxload 61/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Half-duplex, 100Mb/s, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:16, output 00:00:00, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 24171000 bits/sec, 2124 packets/sec
  5 minute output rate 3752000 bits/sec, 614 packets/sec
     2684300 packets input, 3962300144 bytes, 0 no buffer
     Received 344 broadcasts (342 multicast)
     0 runts, 0 giants, 0 throttles
     1 input errors, 0 CRC, 1 frame, 0 overrun, 0 ignored
     0 watchdog, 342 multicast, 0 pause input
     0 input packets with dribble condition detected
     309583 packets output, 255885396 bytes, 0 underruns
     5381 output errors, 8423 collisions, 2 interface resets
     0 babbles, 5445 late collision, 18454 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

FDX のロジックの側は

     5381 output errors, 8423 collisions, 2 interface resets
     0 babbles, 5445 late collision, 18454 deferred

このへんのカウンタが(ほぼ?)上昇しないことがわかった。

相互に全力でパケット流し続ける。

iperf3 -s
iperf3 -c 172.18.1.6 -t 3600
iperf3 -s
iperf3 -c 172.18.2.2 -t 3600

ASW201 は FDX のロジックで、 ASW202 は HDX のロジックで動作する。
ASW201 はいつでもフレームを送信し続ける。
同時に ASW202 側でもフレームを送信したらコリジョンが起きたものと判断する。
そして 18454 パケットが deferred される(送信を待機する)。

12時間ぐらい放置したあと。

HDX

ASW201#sh int f0/13
FastEthernet0/13 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0019.2ffc.accd (bia 0019.2ffc.accd)
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Half-duplex, 100Mb/s, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:01, output 00:00:03, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     879767 packets input, 586720930 bytes, 0 no buffer
     Received 56873 broadcasts (55382 multicast)
     0 runts, 36 giants, 0 throttles
     17239 input errors, 17203 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 55382 multicast, 0 pause input
     0 input packets with dribble condition detected
     3455579 packets output, 666514759 bytes, 0 underruns
     0 output errors, 11897 collisions, 2 interface resets
     0 babbles, 0 late collision, 17801 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out
ASW202#sh int f0/13
FastEthernet0/13 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0017.5a3a.7c0d (bia 0017.5a3a.7c0d)
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Half-duplex, 100Mb/s, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:15, output 00:00:01, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     3396105 packets input, 590841071 bytes, 0 no buffer
     Received 2767 broadcasts (2765 multicast)
     0 runts, 0 giants, 0 throttles
     1 input errors, 0 CRC, 1 frame, 0 overrun, 0 ignored
     0 watchdog, 2765 multicast, 0 pause input
     0 input packets with dribble condition detected
     879812 packets output, 586931392 bytes, 0 underruns
     17482 output errors, 46185 collisions, 2 interface resets
     0 babbles, 17354 late collision, 84193 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

tmux, screen のスクロールバックがつらくなってくる。
つらぽよ。

terminal length 0

FDX にする。

ASW201#sh int f0/13
FastEthernet0/13 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0019.2ffc.accd (bia 0019.2ffc.accd)
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:01, output 00:00:02, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     880443 packets input, 586772899 bytes, 0 no buffer
     Received 57481 broadcasts (55982 multicast)
     0 runts, 36 giants, 0 throttles
     17239 input errors, 17203 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 55982 multicast, 0 pause input
     0 input packets with dribble condition detected
     3455687 packets output, 666526536 bytes, 0 underruns
     0 output errors, 11897 collisions, 2 interface resets
     0 babbles, 0 late collision, 17801 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out
ASW202#sh int f0/13
FastEthernet0/13 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0017.5a3a.7c0d (bia 0017.5a3a.7c0d)
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:00, output 00:00:00, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     3396207 packets input, 590852464 bytes, 0 no buffer
     Received 2805 broadcasts (2803 multicast)
     0 runts, 0 giants, 0 throttles
     1 input errors, 0 CRC, 1 frame, 0 overrun, 0 ignored
     0 watchdog, 2803 multicast, 0 pause input
     0 input packets with dribble condition detected
     880442 packets output, 586980014 bytes, 0 underruns
     17482 output errors, 46185 collisions, 2 interface resets
     0 babbles, 17354 late collision, 84193 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

数時間放置して寝た

ASW201#sh int f0/13
FastEthernet0/13 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0019.2ffc.accd (bia 0019.2ffc.accd)
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:01, output 00:00:02, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     910656 packets input, 589062019 bytes, 0 no buffer
     Received 84721 broadcasts (82823 multicast)
     0 runts, 36 giants, 0 throttles
     17239 input errors, 17203 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 82821 multicast, 0 pause input
     0 input packets with dribble condition detected
     3459979 packets output, 666973580 bytes, 0 underruns
     0 output errors, 11897 collisions, 2 interface resets
     0 babbles, 0 late collision, 17801 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out
ASW202#sh int f0/13
FastEthernet0/13 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0017.5a3a.7c0d (bia 0017.5a3a.7c0d)
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:04, output 00:00:01, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     3400501 packets input, 591299636 bytes, 0 no buffer
     Received 4124 broadcasts (4122 multicast)
     0 runts, 0 giants, 0 throttles
     1 input errors, 0 CRC, 1 frame, 0 overrun, 0 ignored
     0 watchdog, 4122 multicast, 0 pause input
     0 input packets with dribble condition detected
     910666 packets output, 589269858 bytes, 0 underruns
     17482 output errors, 46185 collisions, 2 interface resets
     0 babbles, 17354 late collision, 84193 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

カウンタ値でかすぎてよくわからないのでリセットする。

ASW201#clear counters f0/13
Clear "show interface" counters on this interface [confirm]
ASW201#
22:05:07: %CLEAR-5-COUNTERS: Clear counter on interface FastEthernet0/13 by console
ASW202#clear counters f0/13
Clear "show interface" counters on this interface [confirm]
ASW202#
22:05:08: %CLEAR-5-COUNTERS: Clear counter on interface FastEthernet0/13 by console

イーサネットのフレームサイズは最低64バイト

ASW201#sh int f0/13
FastEthernet0/13 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0019.2ffc.accd (bia 0019.2ffc.accd)
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:01, output 00:00:06, output hang never
  Last clearing of "show interface" counters 00:00:05
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
     4 packets input, 264 bytes, 0 no buffer
     Received 6 broadcasts (6 multicast)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 4 multicast, 0 pause input
     0 input packets with dribble condition detected
     0 packets output, 0 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out
ASW202#sh int f0/13
FastEthernet0/13 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0017.5a3a.7c0d (bia 0017.5a3a.7c0d)
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:06, output 00:00:01, output hang never
  Last clearing of "show interface" counters 00:00:05
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 1000 bits/sec, 1 packets/sec
     0 packets input, 0 bytes, 0 no buffer
     Received 0 broadcasts (0 multicast)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 0 multicast, 0 pause input
     0 input packets with dribble condition detected
     4 packets output, 264 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

片方FDX, HDXにする
ルータ同士で同時に ping 飛ばす

R1#ping 172.18.1.2
R2#ping 172.18.1.1
ASW201#sh int f0/13
FastEthernet0/13 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0019.2ffc.accd (bia 0019.2ffc.accd)
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Full-duplex, 100Mb/s, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:01, output 00:00:02, output hang never
  Last clearing of "show interface" counters 00:02:26
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 1000 bits/sec, 2 packets/sec
  5 minute output rate 1000 bits/sec, 1 packets/sec
     350 packets input, 33846 bytes, 0 no buffer
     Received 157 broadcasts (155 multicast)
     0 runts, 0 giants, 0 throttles
     2 input errors, 2 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 153 multicast, 0 pause input
     0 input packets with dribble condition detected
     204 packets output, 23350 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 babbles, 0 late collision, 0 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out
ASW202#sh int f0/13
FastEthernet0/13 is up, line protocol is up (connected)
  Hardware is Fast Ethernet, address is 0017.5a3a.7c0d (bia 0017.5a3a.7c0d)
  MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation ARPA, loopback not set
  Keepalive set (10 sec)
  Half-duplex, 100Mb/s, media type is 100BaseTX
  input flow-control is unsupported output flow-control is unsupported
  ARP type: ARPA, ARP Timeout 04:00:00
  Last input 00:00:18, output 00:00:01, output hang never
  Last clearing of "show interface" counters 00:02:26
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/40 (size/max)
  5 minute input rate 1000 bits/sec, 2 packets/sec
  5 minute output rate 2000 bits/sec, 3 packets/sec
     203 packets input, 23232 bytes, 0 no buffer
     Received 7 broadcasts (7 multicast)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
     0 watchdog, 7 multicast, 0 pause input
     0 input packets with dribble condition detected
     350 packets output, 33846 bytes, 0 underruns
     2 output errors, 1 collisions, 0 interface resets
     0 babbles, 2 late collision, 8 deferred
     0 lost carrier, 0 no carrier, 0 PAUSE output
     0 output buffer failures, 0 output buffers swapped out

正直良くわからん。

     2 output errors, 1 collisions, 0 interface resets
     0 babbles, 2 late collision, 8 deferred

このへんはバイトとかそういうもんじゃなくてパケット単位のことだろう。
イーサネットの最低フレーム長64バイト、最初の64バイトで検出された衝突が 1 collisions
64バイト送出後に検出された衝突が 2 late collisions
そして deferred されたフレーム数が 8 deferred

正直英語がよくわからんのですよ。。。。
単語レベルで調べればなんとなくわかるが文節レベルでちょっと複雑な文章になると細かい意味を捉えるのが辛くなる。
このへんでチョット英語できる人とできない人の明暗が分かれる。

Also, the retransmission of the frames that Switch4 thought were destroyed because of a collision, but might not have been, causes duplicate frames to be received, occasionally causing application connections to fail and routers to lose neighbor relationships.

Google 翻訳にかけたらだいたいわかった。

衝突によってスイッチ4はフレームが破壊されたと認識したことによるフレーム再送は重複したフレームが受信されることになり、時たまアプリケーションの接続失敗やルータのネイバー関係を喪失することがあるらしい。

まとめ

CCIE を取得するにあたって Cisco の洗礼を受けました。
CCIE R&S Official Cert Guide Library を隅々まで理解するためには CCO 大事そうだし(今は cisco.com というらしいが、未だに CCO とよく呼ばれているとのこと)、他のドキュメントも参照して積極的に実機検証する必要があるということがわかった。
それに加えて Cisco Press の Official Cert Guide Library は Written の Blueprint をカバーするだけであって、ラボ試験対策には INE のワークブック等を併用してやる必要があるとのこと。

これ検証するのに 2, 3 週間ぐらい消費してしまった。
CCIE の Do I know this already Quiz ですげー細かい所聞いてきてこんなとこまで聞かれるのかと戦慄した。

References

CCIE R&S Official Cert Guide Library v5.0 Vol.1