PXE与MC-LAG的Fallback机制

2024-10-17
星融元Asterfusion

PXE简介
PXE与SONiC LAG Fallback
PXE与AsterNOS MC-LAG Fallback
AsterNOS的MC-LAG Fallback功能验证

1.PXE简介

PXE（Preboot Execution Environment）是一种网络启动协议，它允许计算机通过网络从远程服务器上获取操作系统镜像并进行安装。PXE装机的基本原理是在服务器启动时，通过网络请求IP地址和PXE相关配置信息。然后，服务器通过TFTP（Trivial File Transfer Protocol）从PXE服务器下载启动文件，启动文件负责进一步的操作系统安装过程。最终，操作系统镜像文件通过网络传输到服务器，并完成操作系统的安装。

2.PXE与SONiC LAG Fallback

在服务器通过PXE启动的过程中，是无操作系统的状态，无法和交换机之间建立LAG连接、无法发送LACP报文，此时交换机的LAG成员端口都是Inactive状态，也就不会转发DHCP Discover广播报文，PXE流程也就无法继续进行下去。

SONiC LAG Fallback就是解决这个问题的，通过对LAG开启Fallback配置，使其在没有收到LACP报文的情况下，LAG组中的一个成员口会被设为Active状态，使得PXE启动过程能顺利完成。收到LACP后会自动退出Fallback状态。

3.PXE与AsterNOS MC-LAG Fallback

MC-LAG（Multi Chassis Link Aggregation Group，跨设备链路聚合组）是一种实现跨设备链路聚合的机制，通过将一台设备与另外两台设备进行跨设备链路聚合，保留了普通链路聚合的所有优点，同时提供了设备级别的冗余。

MC-LAG将两台物理设备虚拟成单台逻辑设备，这台虚拟出来的“单个设备”与其相连的上行或下行设备实现“一对一”链路聚合。因此，在MC-LAG场景中也会存在LAG场景下PXE装机遇到的问题，AsterNOS目前在LAG和MC-LAG场景都已经支持了Fallback功能。

4.AsterNOS的MC-LAG Fallback功能验证

在Centos76-1上完成mode4 bond配置、DHCP Server配置：

[root@server1 dhcp]# cat /proc/net/bonding/bond0 
Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011)

Bonding Mode: IEEE 802.3ad Dynamic link aggregation
Transmit Hash Policy: layer2 (0)
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 0
Down Delay (ms): 0

802.3ad info
LACP rate: slow
Min links: 0
Aggregator selection policy (ad_select): stable
System priority: 65535
System MAC address: 0c:0a:0e:54:00:01
Active Aggregator Info:
        Aggregator ID: 3
        Number of ports: 2
        Actor Key: 9
        Partner Key: 0
        Partner Mac Address: 52:54:00:12:34:56

Slave Interface: eth1
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: 0c:0a:0e:54:00:01
Slave queue ID: 0
Aggregator ID: 3
Actor Churn State: none
Partner Churn State: none
Actor Churned Count: 0
Partner Churned Count: 0
details actor lacp pdu:
    system priority: 65535
    system mac address: 0c:0a:0e:54:00:01
    port key: 9
    port priority: 255
    port number: 1
    port state: 61
details partner lacp pdu:
    system priority: 65535
    system mac address: 52:54:00:12:34:56
    oper key: 0
    port priority: 255
    port number: 2
    port state: 63

Slave Interface: eth2
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: 0c:0a:0e:54:00:02
Slave queue ID: 0
Aggregator ID: 3
Actor Churn State: none
Partner Churn State: none
Actor Churned Count: 0
Partner Churned Count: 0
details actor lacp pdu:
    system priority: 65535
    system mac address: 0c:0a:0e:54:00:01
    port key: 9
    port priority: 255
    port number: 2
    port state: 61
details partner lacp pdu:
    system priority: 65535
    system mac address: 52:54:00:12:34:56
    oper key: 0
    port priority: 255
    port number: 2
    port state: 63
[root@server1 dhcp]# 
[root@server1 dhcp]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 0c:0a:0e:54:00:00 brd ff:ff:ff:ff:ff:ff
    inet 10.240.3.121/24 brd 10.240.3.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::e0a:eff:fe54:0/64 scope link 
       valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 state UP group default qlen 1000
    link/ether 0c:0a:0e:54:00:01 brd ff:ff:ff:ff:ff:ff
4: eth2: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 state UP group default qlen 1000
    link/ether 0c:0a:0e:54:00:01 brd ff:ff:ff:ff:ff:ff
5: eth3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 0c:0a:0e:54:00:03 brd ff:ff:ff:ff:ff:ff
6: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 0c:0a:0e:54:00:01 brd ff:ff:ff:ff:ff:ff
    inet 172.16.10.1/24 brd 172.16.10.255 scope global bond0
       valid_lft forever preferred_lft forever
    inet6 fe80::e0a:eff:fe54:1/64 scope link 
       valid_lft forever preferred_lft forever
[root@server1 dhcp]# cat dhcpd.conf 
#
# DHCP Server Configuration file.
#   see /usr/share/doc/dhcp*/dhcpd.conf.example
#   see dhcpd.conf(5) man page
#

subnet 172.16.10.0 netmask 255.255.255.0 {
  range 172.16.10.100 172.16.10.200;
  #option routers 172.16.10.254;
  #option domain-name-servers 223.5.5.5;
}
[root@server1 dhcp]#

在Leaf1和2上完成MC-LAG配置，并确认状态正常

leaf1# show mclag state 
The MCLAG's keepalive is: OK
MCLAG info sync is: completed
Domain id: 1
MCLAG session Channel: Primary channel
VRF Name: default
consistency Check Action: idle
Local Ip: 12.12.12.1
Peer Ip: 12.12.12.2
Dad Local Ip: 
Dad Peer Ip: 
Peer Link Interface: lag 99
Keepalive time: 1
Dad Detection Delay: 15
Dad Recovery Delay Mlag Intf: 60
Dad Recovery Delay Non Mlag Intf: 0
Dad VRF Name: default
Dad Status: disable
session Timeout : 15
Peer Link Mac: 52:54:00:12:34:56 
Admin Role: None
Role: Active
MCLAG Interface: lag 2,lag 1
Loglevel: NOTICE   
leaf1# show link-aggregation summary
Flags: A - active, I - inactive, Up - up, Dw - Down, N/A - not available,
       S - selected, D - deselected, * - not synced
  No.  Team Dev         Protocol     Ports          Description
-----  ---------------  -----------  -------------  -------------
 0001  lag 1            LACP(A)(Up)  0/1      (S)   N/A
 0002  lag 2            LACP(A)(Dw)  0/2      (D)   N/A
 0099  lag 99           LACP(A)(Up)  0/9      (S)   N/A
                                     0/8      (S)
leaf1# 

leaf2# show mclag state 
The MCLAG's keepalive is: OK
MCLAG info sync is: completed
Domain id: 1
MCLAG session Channel: Primary channel
VRF Name: default
consistency Check Action: idle
Local Ip: 12.12.12.2
Peer Ip: 12.12.12.1
Dad Local Ip: 
Dad Peer Ip: 
Peer Link Interface: lag 99
Keepalive time: 1
Dad Detection Delay: 15
Dad Recovery Delay Mlag Intf: 60
Dad Recovery Delay Non Mlag Intf: 0
Dad VRF Name: default
Dad Status: disable
session Timeout : 15
Peer Link Mac: 52:54:00:12:34:57 
Admin Role: None
Role: Standby
MCLAG Interface: lag 2,lag 1
Loglevel: NOTICE
leaf2# show link-aggregation summary
Flags: A - active, I - inactive, Up - up, Dw - Down, N/A - not available,
       S - selected, D - deselected, * - not synced
  No.  Team Dev         Protocol     Ports          Description
-----  ---------------  -----------  -------------  -------------
 0001  lag 1            LACP(A)(Up)  0/1      (S)   N/A
 0002  lag 2            LACP(A)(Dw)  0/2      (D)   N/A
 0099  lag 99           LACP(A)(Up)  0/9      (S)   N/A
                                     0/8      (S)
leaf2#

在Centos76-2的两个业务口上，通过DHCP无法获取IP地址

[root@server2 ~]# ifup eth1

正在确定 eth1 的 IP 信息... 完成。
[root@server2 ~]# ifup eth2

正在确定 eth2 的 IP 信息... 完成。
[root@server2 network-scripts]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 0c:a8:80:2f:00:00 brd ff:ff:ff:ff:ff:ff
    inet 10.240.3.122/24 brd 10.240.3.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::ea8:80ff:fe2f:0/64 scope link 
       valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 0c:a8:80:2f:00:01 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::ea8:80ff:fe2f:1/64 scope link 
       valid_lft forever preferred_lft forever
4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 0c:a8:80:2f:00:02 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::ea8:80ff:fe2f:2/64 scope link 
       valid_lft forever preferred_lft forever
5: eth3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 0c:a8:80:2f:00:03 brd ff:ff:ff:ff:ff:ff
[root@server2 network-scripts]#

在Leaf1和2上的LAG2接口组上，启用Fallback功能，AsterNOS会暂时保持一侧端口被激活，在收到LACP协商报文后恢复动态聚合模式

leaf1# show link-aggregation summary 
Flags: A - active, I - inactive, Up - up, Dw - Down, N/A - not available,
       S - selected, D - deselected, * - not synced
  No.  Team Dev         Protocol     Ports          Description
-----  ---------------  -----------  -------------  -------------
 0001  lag 1            LACP(A)(Up)  0/1      (S)   N/A
 0002  lag 2            LACP(A)(Dw)  0/2      (D)   N/A
 0099  lag 99           LACP(A)(Up)  0/8      (S)   N/A
                                     0/9      (S)
启用Fallback：
leaf1# configure terminal 
leaf1(config)# interface link-aggregation 2
leaf1(config-lagif-2)# show this
!
interface link-aggregation 2
 lacp fallback
 lacp fast-rate
 commit
 switchport access vlan 512
leaf1(config-lagif-2)# end
leaf1# show link-aggregation summary 
Flags: A - active, I - inactive, Up - up, Dw - Down, N/A - not available,
       S - selected, D - deselected, * - not synced
  No.  Team Dev         Protocol     Ports          Description
-----  ---------------  -----------  -------------  -------------
 0001  lag 1            LACP(A)(Up)  0/1      (S)   N/A
 0002  lag 2            LACP(A)(Up)  0/2      (S)   N/A
 0099  lag 99           LACP(A)(Up)  0/9      (S)   N/A
                                     0/8      (S)
leaf1# 


leaf2# show link-aggregation summary 
Flags: A - active, I - inactive, Up - up, Dw - Down, N/A - not available,
       S - selected, D - deselected, * - not synced
  No.  Team Dev         Protocol     Ports          Description
-----  ---------------  -----------  -------------  -------------
 0001  lag 1            LACP(A)(Up)  0/1      (S)   N/A
 0002  lag 2            LACP(A)(Dw)  0/2      (D)   N/A
 0099  lag 99           LACP(A)(Up)  0/8      (S)   N/A
                                     0/9      (S)
启用Fallback：
leaf2# configure terminal 
leaf2(config)# interface link-aggregation 2
leaf2(config-lagif-2)# show this
!
interface link-aggregation 2
 lacp fallback
 lacp fast-rate
 commit
 switchport access vlan 512
leaf2(config-lagif-2)# end
leaf2# show link-aggregation summary 
Flags: A - active, I - inactive, Up - up, Dw - Down, N/A - not available,
       S - selected, D - deselected, * - not synced
  No.  Team Dev         Protocol     Ports          Description
-----  ---------------  -----------  -------------  -------------
 0001  lag 1            LACP(A)(Up)  0/1      (S)   N/A
 0002  lag 2            LACP(A)(Dw)  0/2      (D)   N/A
 0099  lag 99           LACP(A)(Up)  0/8      (S)   N/A
                                     0/9      (S)
leaf2#

在Centos76-2的两个业务口上，其中一个口能通过DHCP获取到IP地址

[root@server2 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 0c:a8:80:2f:00:00 brd ff:ff:ff:ff:ff:ff
    inet 10.240.3.122/24 brd 10.240.3.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::ea8:80ff:fe2f:0/64 scope link 
       valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
    link/ether 0c:a8:80:2f:00:01 brd ff:ff:ff:ff:ff:ff
4: eth2: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
    link/ether 0c:a8:80:2f:00:02 brd ff:ff:ff:ff:ff:ff
5: eth3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 0c:a8:80:2f:00:03 brd ff:ff:ff:ff:ff:ff
[root@server2 ~]# ifup eth1

正在确定 eth1 的 IP 信息... 完成。
[root@server2 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 0c:a8:80:2f:00:00 brd ff:ff:ff:ff:ff:ff
    inet 10.240.3.122/24 brd 10.240.3.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::ea8:80ff:fe2f:0/64 scope link 
       valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 0c:a8:80:2f:00:01 brd ff:ff:ff:ff:ff:ff
    inet 172.16.10.100/24 brd 172.16.10.255 scope global dynamic eth1
       valid_lft 43197sec preferred_lft 43197sec
    inet6 fe80::ea8:80ff:fe2f:1/64 scope link 
       valid_lft forever preferred_lft forever
4: eth2: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
    link/ether 0c:a8:80:2f:00:02 brd ff:ff:ff:ff:ff:ff
5: eth3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 0c:a8:80:2f:00:03 brd ff:ff:ff:ff:ff:ff
[root@server2 ~]# ifup eth2

正在确定 eth2 的 IP 信息... 完成。
[root@server2 ~]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 0c:a8:80:2f:00:00 brd ff:ff:ff:ff:ff:ff
    inet 10.240.3.122/24 brd 10.240.3.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::ea8:80ff:fe2f:0/64 scope link 
       valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 0c:a8:80:2f:00:01 brd ff:ff:ff:ff:ff:ff
    inet 172.16.10.100/24 brd 172.16.10.255 scope global dynamic eth1
       valid_lft 42370sec preferred_lft 42370sec
    inet6 fe80::ea8:80ff:fe2f:1/64 scope link 
       valid_lft forever preferred_lft forever
4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 0c:a8:80:2f:00:02 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::ea8:80ff:fe2f:2/64 scope link 
       valid_lft forever preferred_lft forever
5: eth3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 0c:a8:80:2f:00:03 brd ff:ff:ff:ff:ff:ff
[root@server2 ~]#

在DHCP Server上能看到租约信息

[root@server1 dhcp]# cat /var/lib/dhcpd/dhcpd.leases
# The format of this file is documented in the dhcpd.leases(5) manual page.
# This lease file was written by isc-dhcp-4.2.5

server-duid "\000\001\000\001.,\333g\014\012\016T\000\001";

lease 172.16.10.100 {
  starts 5 2024/07/19 08:08:19;
  ends 5 2024/07/19 20:08:19;
  cltt 5 2024/07/19 08:08:19;
  binding state active;
  next binding state free;
  rewind binding state free;
  hardware ethernet 0c:a8:80:2f:00:01;
  client-hostname "server2";
}
[root@server1 dhcp]# systemctl status dhcpd
● dhcpd.service - DHCPv4 Server Daemon
   Loaded: loaded (/usr/lib/systemd/system/dhcpd.service; disabled; vendor preset: disabled)
   Active: active (running) since 五 2024-07-19 08:11:09 UTC; 1h 13min ago
     Docs: man:dhcpd(8)
           man:dhcpd.conf(5)
 Main PID: 4036 (dhcpd)
   Status: "Dispatching packets..."
   CGroup: /system.slice/dhcpd.service
           └─4036 /usr/sbin/dhcpd -f -cf /etc/dhcp/dhcpd.conf -user dhcpd -group dhcpd --no-pid

7月 19 08:11:09 server1 dhcpd[4036]: 
7月 19 08:11:09 server1 dhcpd[4036]: No subnet declaration for eth0 (10.240.3.121).
7月 19 08:11:09 server1 dhcpd[4036]: ** Ignoring requests on eth0.  If this is not what
7月 19 08:11:09 server1 dhcpd[4036]:    you want, please write a subnet declaration
7月 19 08:11:09 server1 dhcpd[4036]:    in your dhcpd.conf file for the network segment
7月 19 08:11:09 server1 dhcpd[4036]:    to which interface eth0 is attached. **
7月 19 08:11:09 server1 dhcpd[4036]: 
7月 19 08:11:09 server1 dhcpd[4036]: Sending on   Socket/fallback/fallback-net
7月 19 08:11:58 server1 dhcpd[4036]: DHCPREQUEST for 172.16.10.100 from 0c:a8:80:2f:00:01 (server2) via bond0
7月 19 08:11:58 server1 dhcpd[4036]: DHCPACK on 172.16.10.100 to 0c:a8:80:2f:00:01 (server2) via bond0
[root@server1 dhcp]#

在Centos76-2上对两个业务口做bond，观察到Leaf1和2上LAG2的成员口都进入Active状态，Fallback功能生效，LAG2恢复动态聚合模式

[root@server2 network-scripts]# ifup bond0
[root@server2 network-scripts]# cat /proc/net/bonding/bond0 
Ethernet Channel Bonding Driver: v3.7.1 (April 27, 2011)

Bonding Mode: IEEE 802.3ad Dynamic link aggregation
Transmit Hash Policy: layer2 (0)
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 0
Down Delay (ms): 0

802.3ad info
LACP rate: slow
Min links: 0
Aggregator selection policy (ad_select): stable
System priority: 65535
System MAC address: 0c:a8:80:2f:00:01
Active Aggregator Info:
        Aggregator ID: 2
        Number of ports: 2
        Actor Key: 9
        Partner Key: 0
        Partner Mac Address: 52:54:00:12:34:56

Slave Interface: eth2
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: 0c:a8:80:2f:00:02
Slave queue ID: 0
Aggregator ID: 2
Actor Churn State: none
Partner Churn State: none
Actor Churned Count: 0
Partner Churned Count: 0
details actor lacp pdu:
    system priority: 65535
    system mac address: 0c:a8:80:2f:00:01
    port key: 9
    port priority: 255
    port number: 2
    port state: 61
details partner lacp pdu:
    system priority: 65535
    system mac address: 52:54:00:12:34:56
    oper key: 0
    port priority: 255
    port number: 3
    port state: 63

Slave Interface: eth1
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 0
Permanent HW addr: 0c:a8:80:2f:00:01
Slave queue ID: 0
Aggregator ID: 2
Actor Churn State: monitoring
Partner Churn State: monitoring
Actor Churned Count: 0
Partner Churned Count: 0
details actor lacp pdu:
    system priority: 65535
    system mac address: 0c:a8:80:2f:00:01
    port key: 9
    port priority: 255
    port number: 3
    port state: 61
details partner lacp pdu:
    system priority: 65535
    system mac address: 52:54:00:12:34:56
    oper key: 0
    port priority: 255
    port number: 3
    port state: 63
[root@server2 network-scripts]# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 0c:a8:80:2f:00:00 brd ff:ff:ff:ff:ff:ff
    inet 10.240.3.122/24 brd 10.240.3.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::ea8:80ff:fe2f:0/64 scope link 
       valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 state UP group default qlen 1000
    link/ether 0c:a8:80:2f:00:01 brd ff:ff:ff:ff:ff:ff
4: eth2: <BROADCAST,MULTICAST,SLAVE,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master bond0 state UP group default qlen 1000
    link/ether 0c:a8:80:2f:00:01 brd ff:ff:ff:ff:ff:ff
5: eth3: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 0c:a8:80:2f:00:03 brd ff:ff:ff:ff:ff:ff
6: bond0: <BROADCAST,MULTICAST,MASTER,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 0c:a8:80:2f:00:01 brd ff:ff:ff:ff:ff:ff
    inet 172.16.10.101/24 brd 172.16.10.255 scope global bond0
       valid_lft forever preferred_lft forever
    inet6 fe80::ea8:80ff:fe2f:1/64 scope link 
       valid_lft forever preferred_lft forever
[root@server2 network-scripts]# ping 172.16.10.1 -c 4
PING 172.16.10.1 (172.16.10.1) 56(84) bytes of data.
64 bytes from 172.16.10.1: icmp_seq=1 ttl=64 time=5.38 ms
64 bytes from 172.16.10.1: icmp_seq=2 ttl=64 time=3.29 ms
64 bytes from 172.16.10.1: icmp_seq=3 ttl=64 time=3.97 ms
64 bytes from 172.16.10.1: icmp_seq=4 ttl=64 time=3.11 ms

--- 172.16.10.1 ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3005ms
rtt min/avg/max/mdev = 3.115/3.943/5.389/0.895 ms
[root@server2 network-scripts]# 

leaf1# show link-aggregation summary 
Flags: A - active, I - inactive, Up - up, Dw - Down, N/A - not available,
       S - selected, D - deselected, * - not synced
  No.  Team Dev         Protocol     Ports          Description
-----  ---------------  -----------  -------------  -------------
 0001  lag 1            LACP(A)(Up)  0/1      (S)   N/A
 0002  lag 2            LACP(A)(Up)  0/2      (S)   N/A
 0099  lag 99           LACP(A)(Up)  0/9      (S)   N/A
                                     0/8      (S)
leaf1# 
leaf2# show link-aggregation summary 
Flags: A - active, I - inactive, Up - up, Dw - Down, N/A - not available,
       S - selected, D - deselected, * - not synced
  No.  Team Dev         Protocol     Ports          Description
-----  ---------------  -----------  -------------  -------------
 0001  lag 1            LACP(A)(Up)  0/1      (S)   N/A
 0002  lag 2            LACP(A)(Up)  0/2      (S)   N/A
 0099  lag 99           LACP(A)(Up)  0/8      (S)   N/A
                                     0/9      (S)
leaf2#

A-lab-部署验证

CX-N系列超低时延云交换机

CX-M系列云化园区交换机

AsterNOS

智算中心/数据中心

云化园区

PXE与MC-LAG的Fallback机制

1.PXE简介

2.PXE与SONiC LAG Fallback

3.PXE与AsterNOS MC-LAG Fallback

4.AsterNOS的MC-LAG Fallback功能验证

在Centos76-1上完成mode4 bond配置、DHCP Server配置：

在Leaf1和2上完成MC-LAG配置，并确认状态正常

在Centos76-2的两个业务口上，通过DHCP无法获取IP地址

在Leaf1和2上的LAG2接口组上，启用Fallback功能，AsterNOS会暂时保持一侧端口被激活，在收到LACP协商报文后恢复动态聚合模式

在Centos76-2的两个业务口上，其中一个口能通过DHCP获取到IP地址

在DHCP Server上能看到租约信息

在Centos76-2上对两个业务口做bond，观察到Leaf1和2上LAG2的成员口都进入Active状态，Fallback功能生效，LAG2恢复动态聚合模式

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AI/超算/云数据中心

CX-N系列超低时延云交换机

云化园区

CX-M系列云化园区交换机

网络操作系统（SONiC）

AsterNOS

可视交换机

开放硬件平台

应用场景

智算中心/数据中心

云化园区

行业应用

PXE与MC-LAG的Fallback机制

1.PXE简介

2.PXE与SONiC LAG Fallback

3.PXE与AsterNOS MC-LAG Fallback

4.AsterNOS的MC-LAG Fallback功能验证

在Centos76-1上完成mode4 bond配置、DHCP Server配置：

在Leaf1和2上完成MC-LAG配置，并确认状态正常

在Centos76-2的两个业务口上，通过DHCP无法获取IP地址

在Leaf1和2上的LAG2接口组上，启用Fallback功能，AsterNOS会暂时保持一侧端口被激活，在收到LACP协商报文后恢复动态聚合模式

在Centos76-2的两个业务口上，其中一个口能通过DHCP获取到IP地址

在DHCP Server上能看到租约信息

在Centos76-2上对两个业务口做bond，观察到Leaf1和2上LAG2的成员口都进入Active状态，Fallback功能生效，LAG2恢复动态聚合模式

对星融元产品感兴趣？

如何联系我们？

400-098-9811

产品中心

快速导航

关注星融元