Port Bonding on Linux & Network
Port Bonding Setup
Port bonding allows you to combine two ports to allow more throughput for your server
Setup on CentOS
It is important that the mode and xmit_hash_policy be set correctly.
edit /etc/modprobe.conf
add:
alias bond0 bonding
create /etc/sysconfig/network-scripts/ifcfg-bond0
add:
DEVICE=bond0 ONBOOT=yes BOOTPROTO=none IPADDR= NETMASK= GATEWAY= USERCTL=no BONDING_MASTER="yes" BONDING_MODULE_OPTS="mode=802.3ad xmit_hash_policy=layer3+4 miimon=100" BONDING_SLAVE0="eth0" BONDING_SLAVE1="eth1"
edit /etc/sysconfig/network-scripts/ifcfg-eth0
change to:
DEVICE=eth0 ONBOOT=yes BOOTPROTO=none USERCTL=no MASTER=bond0 SLAVE=yes
edit /etc/sysconfig/network-scripts/ifcfg-eth1
change to:
DEVICE=eth1 ONBOOT=yes BOOTPROTO=none USERCTL=no MASTER=bond0 SLAVE=yes
Server Side Complete.
Switch Side Setup
Example Information
For the Example Below we shall assume:
That there’s only Portchannel 1.
The Switchports are Gi0/1 and Gi0/2.
That Portchannel 2 is currently nonexistent.
Vlan 990
Check what is set
Check your interfaces – this also puts in the buffer the older information in case of errors
show run int Gi0/1 show run int Gi0/2
Check the Portchannel Summary Information
show etherchannel summary
The Above will show you what Portchannels are in place already.
Start Configuring
Start the Configuration Terminal
conf t
Select The First Interface of the Port Channel – Here it’s Gi0/1
int Gi0/1
Utilize the Channel Group Command -this creates the Port Channel- Using Channel 2 here because 1 is always reserved -and in use!
channel-group 2 mode on
“Creating a port-channel interface Port-channel 2″ YOU SHOULD SEE THIS
Switch over to the second interface of the Port Channel (faster than “end” then “conf t” then “int Gi0/2″)
int Gi0/2
Utilize the Channel Group Command Again
channel-group 2 mode on
(It shouldn’t say anything this time)
Switch to your shiny new Portchannel
int po2
The Portchannel takes commands. This process overwrites whatever is there. Let’s use info for Vlan 990
Set the switchport Access to Vlan 990
switchport access vlan 990
Set the Switchport Mode to Access
switchport mode access
Set the Load interval to 30 (this sets the polling interval to 30 seconds.)
load-interval 30
Disable Portfast on bonded ports – this prevents a spanning tree loop while the port channel negotiates.
no spanning-tree portfast
End editing
end
Verify and Save
Before you write one last look at the new configuration for the port channel
show run int po2 Building configuration... Current configuration : 125 bytes ! interface Port-channel2 switchport access vlan 990 switchport mode access load-interval 30 spanning-tree portfast end
And then a last glance at the 2 ports in the portchannel for consistency, then the portchannel summary one last time.
show run int Gi0/1 Building configuration... Current configuration : 155 bytes ! interface GigabitEthernet0/1 switchport access vlan 990 switchport mode access load-interval 30 channel-group 2 mode on spanning-tree portfast end show run int Gi0/2 Building configuration... Current configuration : 155 bytes ! interface GigabitEthernet0/2 switchport access vlan 990 switchport mode access load-interval 30 channel-group 2 mode on spanning-tree portfast end
Check the Portchannel summary
show etherchannel summary Flags: D - down P - in port-channel I - stand-alone s - suspended H - Hot-standby (LACP only) R - Layer3 S - Layer2 U - in use f - failed to allocate aggregator u - unsuitable for bundling w - waiting to be aggregated d - default port Number of channel-groups in use: 2 Number of aggregators: 2 Group Port-channel Protocol Ports ------+-------------+-----------+----------------------------------------------- 1 Po1(SU) - Gi0/21(P) Gi0/22(P) Gi0/23(P) Gi0/24(P) 2 Po2(SD) - Gi0/1(D) Gi0/2(D)
Here we see that Po2 is down. This is only because the server’s not attached.
Write your configuration
write
Congratulations your Port Channel to Vlan 990 is complete. PXE Installs should be criminally fast.
Switch Side Complete
