Hello all, again, Still stocked with this NIC binding problem. With Robin's conf both nics work fine in the active-backup config (thanks Robin !) I wanted to go a little bit further & bind both interfaces in an active-active conf. James pointed out the Documentation/networking/bonding.txt. (thanks James!) It states that there is a HA-mode where both NIC'S can work in active-active mode. I've configured the switch to operate in trunk mode for my VLAN and configured my CENTOS box to aggregate the links, but cannot manage to ping my gateway. All interfaces show the same mac addr what is good but, arp -a shows nothing ! Question: Documentation does not say how or if you have to configure de bonding mode for HA in /etc/modprobe.conf. From my point of view it should be mode=6 (balance-alb), but since it does not work I must be wrong! Or should it be left empty ? Any clues ? Could it be the switch ? Thanks, Nassri My conf: Switch - Cisco 3750 interface GigabitEthernet1/0/19 description DNS1 switchport trunk encapsulation dot1q switchport trunk allowed vlan 201 switchport mode trunk end ! interface GigabitEthernet1/0/18 description DNS2 switchport trunk encapsulation dot1q switchport trunk allowed vlan 201 switchport mode trunk end CENTOS BOX /etc/sysconfig/network-scripts/ifcfg-eth0 & ifcfg-eth1 DEVICE=ethx BOOTPROTO=static TYPE=Ethernet ONBOOT=yes SLAVE=yes MASTER=bond0 etc/sysconfig/network-scripts/ifcfg-bond0 DEVICE=bond0 ONBOOT=yes IPADDR=10.10.4.27 NETMASK=255.255.255.0 /etc/modprobe.conf alias bond0 bonding options bonding miimon=100 alias eth0 tg3 alias eth1 tg3 < /etc/sysconfig/network > NETWORKING=yes HOSTNAME=dns GATEWAY=10.192.32.254 GATEWAYDEV=bond0 > I have not had time to test this, but the documentation > states that it can be done with some of the other mode=x > numbers, where the mode number represents different types of > bonding ie. round robin, active/standby, etc.. >