Channel Bonding and Hareware address

[Randy Hagedorn]

HI,

I am rebuilding the second node of a a two node ServiceGurard cluster which is a BL480C attached to an EVA4100. In the SG deployment guide, it has instructions on setting up channel bonding and instructs to create new /etc/sysconfig/network-scripts/ifcfg-ethN files by deleting all but DEVICE and HWADDR entries and adding several other entries. Which makes sense not to delete hwaddr.

On our first node however, when looking at its /etc/sysconfig/network-scripts/ifcfg-ethN files, it has NO HWADDR entry. How does the system know the HWADDR when its not in the config. files? I'm afraid of removing the hwaddr from the second node and not being able to communicate with it.

Here is a portion of the first nodes ifconfig info:
eth0 Link encap:Ethernet HWaddr 00:17:A4:77:24:04
inet6 addr: fe80::217:a4ff:fe77:2404/64 Scope:Link
UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1
RX packets:2470458953 errors:0 dropped:0 overruns:0 frame:0
TX packets:5957147847 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:267369864910 (249.0 GiB) TX bytes:7935428466539 (7.2 TiB)
Interrupt:169 Memory:f8000000-f8012100

eth1 Link encap:Ethernet HWaddr 00:17:A4:77:24:04
inet6 addr: fe80::217:a4ff:fe77:2404/64 Scope:Link
UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1
RX packets:45504818 errors:0 dropped:0 overruns:0 frame:0
TX packets:196 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:3822984201 (3.5 GiB) TX bytes:15617 (15.2 KiB)
Interrupt:177 Memory:fa000000-fa012100

Thanks,
Randy

[Steven E. Protter · Accepted solution]

Shalom Randy,

The system picks up the hardware address from the hardware itself. It does not rely on the configuration files.

When you bond, the first NIC card recognized is usually adopted to be the bond hardware device.

This answer applies to Centos/Red Hat type distributions.

SEP

[Tim Nelson]

Here are my tips to configure active/backup bond that needs no additional switch configurations.

/etc/modprobe.conf
alias bond0 bonding

/etc/sysconfig/network-scripts/ifcfg-bond0
DEVICE=bond0
IPADDR=xxx.xxx.xxx.xxx
NETMASK=255.255.255.xxx
BROADCAST=xxx.xx.xx.0
ONBOOT=YES
BOOTPROTO=none
USERCTL=no
TYPE=Bonding
BONDING_OPTS="mode=1 miimon=100"

/etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
USERCTL=no
ONBOOT=yes
MASTER=bond0
BOOTPROTO=none
SLAVE=yes

/etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth1
USERCTL=no
ONBOOT=yes
MASTER=bond0
BOOTPROTO=none
SLAVE=yes


cat /proc/net/bonding/bond0
Ethernet Channel Bonding Driver: v3.4.0 (October 7, 2008)

Bonding Mode: fault-tolerance (active-backup)
Primary Slave: None
Currently Active Slave: eth0
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 0
Down Delay (ms): 0

Slave Interface: eth0
MII Status: up
Link Failure Count: 0
Permanent HW addr: 78:e7:d1:7b:d0:de

Slave Interface: eth1
MII Status: up
Link Failure Count: 0
Permanent HW addr: 78:e7:d1:7b:d0:e0


ifconfig
bond0 Link encap:Ethernet HWaddr 78:E7:D1:7B:D0:DE
inet addr:xxx.xxx.xxx.xxx Bcast:xxx.xxx.xxx.255 Mask:255.255.255.0
inet6 addr: fe80::7ae7:d1ff:fe7b:d0de/64 Scope:Link
UP BROADCAST RUNNING MASTER MULTICAST MTU:1500 Metric:1
RX packets:3315908 errors:0 dropped:0 overruns:0 frame:0
TX packets:8081828 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:281361701 (268.3 MiB) TX bytes:10959873055 (10.2 GiB)

eth0 Link encap:Ethernet HWaddr 78:E7:D1:7B:D0:DE
UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1
RX packets:3169412 errors:0 dropped:0 overruns:0 frame:0
TX packets:8081828 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:271976240 (259.3 MiB) TX bytes:10959873055 (10.2 GiB)
Interrupt:177 Memory:f4000000-f4012800

eth1 Link encap:Ethernet HWaddr 78:E7:D1:7B:D0:DE
UP BROADCAST RUNNING SLAVE MULTICAST MTU:1500 Metric:1
RX packets:146496 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:9385461 (8.9 MiB) TX bytes:0 (0.0 b)
Interrupt:162 Memory:f2000000-f2012800