Dear all, Has anyone experienced this whilst running DRBD over eth1 between two CentOS 5.7 servers? eth1 is a private IP address, unroutable. eth0 is the public address. CentOS will reply sometimes once every 3 days or every 14mins~ saying "My public IP is on eth1" to arp requests when it's not, it's eth0. This freezes traffic and causes issues. We've looked at arp* /etc/sysctl.conf etc. and arptables, but wondered if anyone had a recipe? We have this already which didn't help as it happened Christmas Eve too as we kept eth1 up for a few days to test: # For the dual interface - 06.12.12 net.ipv4.conf.eth0.arp_filter = 1 net.ipv4.conf.eth0.arp_ignore = 1 net.ipv4.conf.eth1.arp_filter = 1 net.ipv4.conf.eth1.arp_ignore = 1 net.ipv4.conf.all.arp_filter = 1 eth0 and eth1 are on the same VLAN/broadcast domain, but eth1 is a 169.xx and eth0 is a routable public IP. We're having to shut eth1 down and bring it up for sync at night. Thanks, Gavin.