Linux – Host using Linux bond mode 1 (active/backup) connected to 2 x independent switches

bondinglinuxredundancyswitch

I have a host using Linux bond mode 1 (active/backup) connected to 2 x independent switches. Please can someone confirm if this is possible for successful failover between NICS or do I have to interconnect the two switches? If this is already answered someplace please point me to the resource

Specification:-
The 6.5 linux host is configured with the following ifconfig-bond1 files:-

[Server1 network-scripts]$ cat ifcfg-bond1
DEVICE=bond1
ONBOOT=yes
USERCTL=no
IPV6INIT=no
PEERDNS=yes
DHCP_HOSTNAME=Server1
BOOTPROTO=none
IPADDR=192.168.49.11
NETMASK=255.255.255.0
GATEWAY=192.168.49.254
BONDING_OPTS="mode=1 miimon=100 downdelay=200 updelay=200"

and 1Gbe eth0/1 interface files work like this:-

[server1 network-scripts]$ cat ifcfg-eth0
DEVICE=eth0
ONBOOT=yes
TYPE=Ethernet
MASTER=bond1
SLAVE=yes
USERCTL=no

[Server1 network-scripts]$ cat ifcfg-eth1
DEVICE=eth1
ONBOOT=yes
TYPE=Ethernet
MASTER=bond1
SLAVE=yes
USERCTL=no

eth0 connects to a primay switch whilst eth1 connects to the backup switch (2 x independent Juniper EX3300 models)

thanks

adam

Best Answer

As long as your bond's IP (192.168.49.11) is reachable VIA either switch, you're fine in mode 1. If you have console access to the server, this is easy enough to test - just bring each of the slave interfaces down one at a time and verify you still have connectivity to the outside world (or wherever you need to reach). However, I wouldn't recommend doing this if you don't have direct console access, as, um, you might cut yourself off from the server if there's an upstream problem.

P.S. I'm not exactly clear on your use of BOTH the terms "independent" and "the backup switch" to refer to your setup.

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