Linux bonding failover issue between two cisco switch

I have above scenario where server has bond0 interface connected to SW1 and SW2 relevant interface of server, last night somehow SW1 got rebooted and server lost eth0 connectivity but it didn't failover to eth1 also every after switch rebooted successfully network was down and this happened on multiple server not single. so finally i have restart network on all server to make it work. we have primary=eth0 set in bond0 configuration. ifcfg-bond0 DEVICE=bond0 BOOTPROTO=none ONBOOT=yes BONDING_OPTS=mode=1 arp_interval=1000 arp_ip_target=192.168.10.1 miimon=500 downdelay=1000 primary=eth0 primary_reselect=always NETMASK=255.255.255.0 IPADDR=192.168.10.20 GATEWAY=192.168.10.1 ifcfg-eth0 DEVICE=eth0 BOOTPROTO=none ONBOOT=yes MASTER=bond0 SLAVE=yes ifcfg-eth1 DEVICE=eth1 BOOTPROTO=none ONBOOT=yes MASTER=bond0 SLAVE=yes This is what i am seeing in logs when this happened [root@server1 ~]# cat /var/log/messages | grep eth Jun 8 05:03:05 s_sys@server1.example.com kernel: : bnx2 0000:02:00.0: eth0: NIC Copper Link is Down Jun 8 05:03:05 s_sys@server1.example.com kernel: : bonding: bond0: link status definitely down for interface eth0, disabling it Jun 8 05:03:05 s_sys@server1.example.com kernel: : bonding: bond0: making interface eth1 the new active one. Jun 8 05:07:03 s_sys@server1.example.com kernel: : bnx2 0000:02:00.0: eth0: NIC Copper Link is Up, 1000 Mbps full duplex Jun 8 05:07:03 s_sys@server1.example.com kernel: : bonding: bond0: link status definitely up for interface eth0. Jun 8 05:20:45 s_sys@server1.example.com kernel: : bonding: bond0: Removing slave eth0 Jun 8 05:20:45 s_sys@server1.example.com kernel: : bonding: bond0: Warning: the permanent HWaddr of eth0 - 18:A9:05:3A:39:1D - is still in use by bond0. Set the HWaddr of eth0 to a different address to avoid conflicts. Jun 8 05:20:45 s_sys@server1.example.com kernel: : bonding: bond0: releasing backup interface eth0 Jun 8 05:20:46 s_sys@server1.example.com kernel: : bonding: bond0: Removing slave eth1 Jun 8 05:20:46 s_sys@server1.example.com kernel: : bonding: bond0: releasing active interface eth1 Jun 8 05:20:46 s_sys@server1.example.com kernel: : bonding: bond0: Adding slave eth0. Jun 8 05:20:46 s_sys@server1.example.com kernel: : bnx2 0000:02:00.0: eth0: using MSIX Jun 8 05:20:46 s_sys@server1.example.com kernel: : bonding: bond0: enslaving eth0 as a backup interface with a down link. Jun 8 05:20:46 s_sys@server1.example.com kernel: : bonding: bond0: Adding slave eth1. Jun 8 05:20:46 s_sys@server1.example.com kernel: : bnx2 0000:02:00.1: eth1: using MSIX Jun 8 05:20:46 s_sys@server1.example.com kernel: : bonding: bond0: enslaving eth1 as a backup interface with a down link. Jun 8 05:20:49 s_sys@server1.example.com kernel: : bnx2 0000:02:00.0: eth0: NIC Copper Link is Up, 1000 Mbps full duplex Jun 8 05:20:49 s_sys@server1.example.com kernel: : bonding: bond0: link status definitely up for interface eth0. Jun 8 05:20:49 s_sys@server1.example.com kernel: : bonding: bond0: making interface eth0 the new active one. Jun 8 05:20:49 s_sys@server1.example.com kernel: : bnx2 0000:02:00.1: eth1: NIC Copper Link is Up, 1000 Mbps full duplex Jun 8 05:20:50 s_sys@server1.example.com kernel: : bonding: bond0: link status definitely up for interface eth1.