Cisco EtherChannel ( btwn SW, btwn SW and RT )

Network

構成

トポロジ図

     |------------------|
[SW1]|                  |[SW2]
     |------------------|

     |------------------|
 [SW]|                  |[RT]
     |------------------|

パラメータ

  • Vlan
    • VlanMode : Trunk
    • Vlan : 10, 20
  • Channel
    • Pattern1
      • Type : L2
      • Protocol : LACP
      • SW1 : active
      • SW2 : active
    • Pattern2
      • Type : L2
      • Protocol : Static
      • SW1 : on
      • SW2 : on
    • Pattern3
      • Type : L3
      • Protocol : Static
      • SW1 : on
      • SW2 : on
    • Pattern4
      • Type : L2, L3
      • Protocol : Static
      • SW : on
      • RT : on
  • IP
    • SW1 <--> SW2
      • Vlan10
        • Segment : 10.0.0.0/24
        • SW1 : 10.0.0.1/24
        • SW2 : 10.0.0.2/24
      • Vlan20
        • Segment : 20.0.0.0/24
        • SW1 : 20.0.0.1/24
        • SW2 : 20.0.0.2/24
    • SW <--> RT
      • Vlan10
        • Segment : 10.0.0.0/24
        • SW : 10.0.0.1/24
        • RT : 10.0.0.2/24
      • Vlan20
        • Segment : 20.0.0.0/24
        • SW : 20.0.0.1/24
        • RT : 20.0.0.2/24

EtherChannelとは

概要

EtherChannelとは一般的にはLink-Aggregation(LAG)やPort-Channelと呼ばれている。
機器の接続を冗長化する為に、複数のI/F接続をまとめて論理的に一つのI/Fとして扱う技術。
STP/RSTPの様にいずれかのI/Fを無効化せずに、負荷分散しつつ使用することが可能。

メリット/デメリット

  • メリット
    • 冗長化 : 複数のI/Fを一つにまとめることにより、何れかが故障しても通信を継続できる
    • 負荷分散 : 通信を分散することで、通常のI/F以上の帯域を使用できる
  • デメリット
    • トラブル対応 : 通信経路が一定でなくなり、障害の特定が困難になる

条件

  • プロトコルを合わせる必要がある
  • リンク速度を合わせる必要がある
  • Duplexモードを合わせる必要がある
  • Vlanモード(Access|Trunk)を合わせる必要がある
  • ネイティブVlanを一致させる必要がある (Trunkの場合)
  • I/Fモード(Swicth|Routed)を一致させる必要がある

種類

Etherchannelには大きく分けて以下の2種類が存在する。
L2-Etherchannel、Switchポート同士でchannelを組むことができる。
L3-Etherchannel、Routedポート同士でchannelを組むことができ、SW同士だけでなくRouterともchannelを組むことができる。

負荷分散の基準となる方式

src-ip          : 送信元IPアドレスを基準とする
dst-ip          : 宛先IPアドレスを基準とする
src-dst-ip      : 送信元/宛先IPアドレスを基準とする

src-mac         : 送信元MACアドレスを基準とする
dst-mac         : 宛先MACアドレスを基準とする
src-dst-mac     : 送信元/宛先MACアドレスを基準とする

src-port        : 送信元ポート番号を基準とする
dst-port        : 宛先ポート番号を基準とする
src-dst-port    : 送信元/宛先ポート番号を基準とする

プロトコル

Static (ON)

概要

対向機器とネゴシエーションをせずに強制的にEtherChannel組む。
RouterとのChannelや機器メーカーが異なる場合は強制で組むStaticが推奨となる。

ネゴシエーション

ネゴシエーション不要で強制LAGを組む

概要

IEEE802.3ad規格で標準化されている一般的なEtherChannelのネゴシエーションプロトコル。
Cisco機器以外でも使用できるので通常はこちらが使用される。
最大16ポートで組むことができるが、通常使用は8ポートで残りはスタンバイとなる。

ネゴシエーション
  • passive : 対向からのネゴシエーション通信を 待機
  • active : 自身からネゴシエーション通信を 送信
    ネゴシエーション対応表
    passive active
    passive NG OK
    active OK OK

PAgP (Port Aggregation Protocol)

概要

Cisco独自のEtherChannelのネゴシエーションプロトコル。 Cisco機器でしか使用できないため、あまり一般的には使用されない。

ネゴシエーション
  • auto : 対向からのネゴシエーション通信を 待機
  • desirable : 自身からネゴシエーション通信を 送信
    ネゴシエーション対応表
    auto desirable
    auto NG OK
    desirable OK OK

Command

port-channel load-balance [MODE]    : 負荷分散方式の指定

interface GigabitEthernet [NO]  : ChannelメンバにするI/F
 channel-group [NO] mode [MODE]     : Channel番号とプロトコル&モードを指定

Show Command

show etherchannel summary
show etherchannel load-balance
show lacp neighbor
show lacp internal
show interfaces port-channel [NO] etherchannel
show platform software fed switch [NO] etherchannel [NO] load-balance

Pattern1 L2 EtherChannel LACP

Configuration

SW1
vlan 10
vlan 20

interface GigabitEthernet0/0
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-group 1 mode active

interface GigabitEthernet0/1
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-group 1 mode active

interface Port-channel1
 switchport trunk encapsulation dot1q
 switchport mode trunk

interface Vlan10
 ip address 10.0.0.1 255.255.255.0
 no shutdown

interface Vlan20
 ip address 20.0.0.1 255.255.255.0
 no shutdown
SW2
vlan 10
vlan 20

interface GigabitEthernet0/0
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-group 1 mode active

interface GigabitEthernet0/1
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-group 1 mode active

interface Port-channel1
 switchport trunk encapsulation dot1q
 switchport mode trunk

interface Vlan10
 ip address 10.0.0.2 255.255.255.0
 no shutdown

interface Vlan20
 ip address 20.0.0.2 255.255.255.0
 no shutdown

Status Check

show etherchannel summary
# show etherchannel summary
Number of channel-groups in use: 1
Number of aggregators:           1

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
1      Po1(SU)         LACP      Gi0/0(P)    Gi0/1(P)
show etherchannel load-balance
# show etherchannel load-balance
EtherChannel Load-Balancing Configuration:
        src-dst-ip

EtherChannel Load-Balancing Addresses Used Per-Protocol:
Non-IP: Source XOR Destination MAC address
  IPv4: Source XOR Destination IP address
  IPv6: Source XOR Destination IP address
show lacp neighbor
SW1# show lacp neighbor
Channel group 1 neighbors

Partner's information:

                  LACP port                        Admin  Oper   Port    Port
Port      Flags   Priority  Dev ID          Age    key    Key    Number  State
Gi0/0     SA      32768     5000.0009.0000  27s    0x0    0x1    0x1     0x3D
Gi0/1     SA      32768     5000.0009.0000   1s    0x0    0x1    0x2     0x3D
show lacp internal
# show lacp internal

Channel group 1
                            LACP port     Admin     Oper    Port        Port
Port      Flags   State     Priority      Key       Key     Number      State
Gi0/0     SA      bndl      32768         0x1       0x1     0x1         0x3D
Gi0/1     SA      bndl      32768         0x1       0x1     0x2         0x3D
show interfaces port-channel [NO] etherchannel
# show interfaces port-channel 1 etherchannel
Port-channel1   (Primary aggregator)

Age of the Port-channel   = 0d:00h:03m:40s
Logical slot/port   = 16/0          Number of ports = 2
HotStandBy port = null
Port state          = Port-channel Ag-Inuse
Protocol            =   LACP
Port security       = Disabled

Ports in the Port-channel:

Index   Load   Port     EC state        No of bits
------+------+------+------------------+-----------
  0     00     Gi0/0    Active             0
  0     00     Gi0/1    Active             0

Time since last port bundled:    0d:00h:00m:28s    Gi0/1

Pattern2 L2 EtherChannel Static

Configuration

SW1
vlan 10
vlan 20

interface GigabitEthernet0/0
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-group 1 mode on

interface GigabitEthernet0/1
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-group 1 mode on

interface Port-channel1
 switchport trunk encapsulation dot1q
 switchport mode trunk

interface Vlan10
 ip address 10.0.0.1 255.255.255.0
 no shutdown

interface Vlan20
 ip address 20.0.0.1 255.255.255.0
 no shutdown
SW2
vlan 10
vlan 20

interface GigabitEthernet0/0
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-group 1 mode on

interface GigabitEthernet0/1
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-group 1 mode on

interface Port-channel1
 switchport trunk encapsulation dot1q
 switchport mode trunk

interface Vlan10
 ip address 10.0.0.2 255.255.255.0
 no shutdown

interface Vlan20
 ip address 20.0.0.2 255.255.255.0
 no shutdown

Status Check

show etherchannel summary
# show etherchannel summary
Number of channel-groups in use: 1
Number of aggregators:           1

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
1      Po1(SU)          -        Gi0/0(P)    Gi0/1(P)
show etherchannel load-balance
# show etherchannel load-balance
EtherChannel Load-Balancing Configuration:
        src-dst-ip

EtherChannel Load-Balancing Addresses Used Per-Protocol:
Non-IP: Source XOR Destination MAC address
  IPv4: Source XOR Destination IP address
  IPv6: Source XOR Destination IP address
show interfaces port-channel [NO] etherchannel
# show interfaces port-channel 1 etherchannel
Age of the Port-channel   = 0d:00h:04m:51s
Logical slot/port   = 16/0          Number of ports = 2
GC                  = 0x00000000      HotStandBy port = null
Port state          = Port-channel Ag-Inuse
Protocol            =    -
Port security       = Disabled

Ports in the Port-channel:

Index   Load   Port     EC state        No of bits
------+------+------+------------------+-----------
  0     00     Gi0/0    On                 0
  0     00     Gi0/1    On                 0

Time since last port bundled:    0d:00h:04m:21s    Gi0/1

Pattern3 L3 EtherChannel Static

Configuration

SW1
interface GigabitEthernet0/0
 no switchport
 channel-group 1 mode on

interface GigabitEthernet0/1
 no switchport
 channel-group 1 mode on

interface Port-channel1
 no switchport
 no ip address

interface Port-channel1.10
 encapsulation dot1Q 10
 ip address 10.0.0.1 255.255.255.0

interface Port-channel1.20
 encapsulation dot1Q 20
 ip address 20.0.0.1 255.255.255.0
SW2
interface GigabitEthernet0/0
 no switchport#
 channel-group 1 mode on

interface GigabitEthernet0/1
 no switchport
 channel-group 1 mode on

interface Port-channel1
 no switchport
 no ip address

interface Port-channel1.10
 encapsulation dot1Q 10
 ip address 10.0.0.2 255.255.255.0

interface Port-channel1.20
 encapsulation dot1Q 20
 ip address 20.0.0.2 255.255.255.0

Status Check

show etherchannel summary
# show etherchannel summary
Number of channel-groups in use: 1
Number of aggregators:           1

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
1      Po1(RU)          -        Gi0/0(P)    Gi0/1(P)
show etherchannel load-balance
# show etherchannel load-balance
EtherChannel Load-Balancing Configuration:
        src-dst-ip

EtherChannel Load-Balancing Addresses Used Per-Protocol:
Non-IP: Source XOR Destination MAC address
  IPv4: Source XOR Destination IP address
  IPv6: Source XOR Destination IP address
show interfaces port-channel [NO] etherchannel
# show interfaces port-channel 1 etherchannel
Age of the Port-channel   = 0d:08h:53m:20s
Logical slot/port   = 16/0          Number of ports = 2
GC                  = 0x00000000      HotStandBy port = null
Passive port list   = Gi0/0 Gi0/1
Port state          = Port-channel L3-Ag Ag-Inuse
Protocol            =    -
Port security       = Disabled

Ports in the Port-channel:

Index   Load   Port     EC state        No of bits
------+------+------+------------------+-----------
  0     00     Gi0/0    On                 0
  0     00     Gi0/1    On                 0

Time since last port bundled:    0d:08h:52m:44s    Gi0/1

Pattern4 L3 EtherChannel Static btwn SW and RT

Configuration

SW
vlan 10
vlan 20

interface GigabitEthernet0/0
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-group 1 mode on

interface GigabitEthernet0/1
 switchport trunk encapsulation dot1q
 switchport mode trunk
 channel-group 1 mode on

interface Port-channel1
 switchport trunk encapsulation dot1q
 switchport mode trunk

interface Vlan10
 ip address 10.0.0.1 255.255.255.0
 no shutdown

interface Vlan20
 ip address 20.0.0.1 255.255.255.0
 no shutdown
RT
interface GigabitEthernet0/0
 no shutdown
 no ip address
 channel-group 1

interface GigabitEthernet0/1
 no shutdown
 no ip address
 channel-group 1

interface Port-channel1
 no ip address

interface Port-channel1.10
 encapsulation dot1Q 10
 ip address 10.0.0.2 255.255.255.0

interface Port-channel1.20
 encapsulation dot1Q 20
 ip address 20.0.0.2 255.255.255.0

Status Check

show etherchannel summary
#show etherchannel summary
Number of channel-groups in use: 1
Number of aggregators:           1

Group  Port-channel  Protocol    Ports
------+-------------+-----------+-----------------------------------------------
1      Po1(SU)          -        Gi0/0(P)    Gi0/1(P)
show etherchannel load-balance
# show etherchannel load-balance
EtherChannel Load-Balancing Configuration:
        src-dst-ip

EtherChannel Load-Balancing Addresses Used Per-Protocol:
Non-IP: Source XOR Destination MAC address
  IPv4: Source XOR Destination IP address
  IPv6: Source XOR Destination IP address
show interfaces port-channel [NO] etherchannel
# show interfaces port-channel 1 etherchannel
Age of the Port-channel   = 0d:00h:08m:39s
Logical slot/port   = 16/0          Number of ports = 2
GC                  = 0x00000000      HotStandBy port = null
Port state          = Port-channel Ag-Inuse
Protocol            =    -
Port security       = Disabled

Ports in the Port-channel:

Index   Load   Port     EC state        No of bits
------+------+------+------------------+-----------
  0     00     Gi0/0    On                 0
  0     00     Gi0/1    On                 0

Time since last port bundled:    0d:00h:08m:36s    Gi0/1