Со стороны центрального коммутатора

Задаётся общее количество интерфейсов ae.

{master:0}[edit chassis aggregated-devices]
root@IMH# show
ethernet {
    device-count 11;
}

ge-0/0/0 {
    description "link1 L3 tu 3 flor new Office sw 48 port_new";
    ether-options {
        802.3ad ae0;
    }
}

ge-1/0/0 {
    description "link L3 tu 3 flor new Office sw 48 port";
    ether-options {
        802.3ad ae0;
    }
}

ae0 {
    description "To 3 floor new Office 1*48";
    aggregated-ether-options {
        lacp {
            active;
        }
    }
    unit 0 {
        family ethernet-switching {
            interface-mode trunk;
            vlan {
                members [ 15 100-102 109 111-112 ];
            }
        }
    }
}

Со стороны второго коммутатора

{master:0}[edit chassis aggregated-devices]
root@sw1# show
ethernet {
    device-count 1;
}

ge-0/1/0 {
    ether-options {
        802.3ad ae0;
    }
}
ge-0/1/1 {
    ether-options {
        802.3ad ae0;
    }
}

ae0 {
    aggregated-ether-options {
        lacp {
            passive;
        }
    }
    unit 0 {
        family ethernet-switching {
            port-mode trunk;
            vlan {
                members [ 111-112 Servers_lan mngm users voice wifi wifi-1 ];
            }
        }
    }
}

Проверяем состояние AE (Aggregated Ethernet)

show interfaces terse | match ae

show interfaces extensive ae0 | find "LACP Statistics:"

LAG и Cisco Wireless 2504

Пробовал на модели: ex4300-32f

set interfaces ae10 description "To Cisco 2504 Wireless Controller 10.10.41.2"
set interfaces ae10 unit 0 family ethernet-switching interface-mode trunk
set interfaces ae10 unit 0 family ethernet-switching vlan members 109-112
set interfaces ge-0/0/30 ether-options 802.3ad ae10
set interfaces ge-1/0/30 ether-options 802.3ad ae10

На контроллере выставляем:
Controller > General >LAG Mode on next reboot
И соединяем порты контроллера 1 и 2 с соответствующими портами коммутатора.

Проверка:
show interfaces ae10
Смотрим Input rate и Output rate.

root@IMH> show interfaces ae10    
Physical interface: ae10, Enabled, Physical link is Up
  Interface index: 678, SNMP ifIndex: 588
  Description: To Cisco 2504 Wireless Controller 10.10.41.2
  Link-level type: Ethernet, MTU: 1514, Speed: 2Gbps, BPDU Error: None, MAC-REWRITE Error: None, Loopback: Disabled, Source filtering: Disabled,
  Flow control: Disabled, Minimum links needed: 1, Minimum bandwidth needed: 1bps
  Device flags   : Present Running
  Interface flags: SNMP-Traps Internal: 0x0
  Current address: 2c:21:31:8a:36:ed, Hardware address: 2c:21:31:8a:36:ed
  Last flapped   : 2018-03-13 12:38:11 MSK (5w1d 00:32 ago)
  Input rate     : 273256 bps (64 pps)
  Output rate    : 2447744 bps (262 pps)

Аналогично смотрим уровни на физических интерфейсах:
show interfaces ge-0/0/30
show interfaces ge-1/0/30