keepalived-1.2.18.tar.gz

Note on using VRRP with Virtual MAC address ============================================= Alexandre Cassen July 11th 2012 To reduce takeover impact, some networking environment would require using VRRP with VMAC address. To reach that goal Keepalived VRRP framework implements VMAC support by the invocation of 'use_vmac' keyword in configuration file. Internally, Keepalived code will bring up virtual interfaces, each interface dedicated to a specific virtual_router. Keepalived uses Linux kernel macvlan driver to defines thoses interfaces. It is then mandatory to use kernel compiled with macvlan support. In addition we can mention that VRRP VMAC will work only with kernel including the following patch : http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commitdiff;h=729e72a10930ef765c11a5a35031ba47f18221c4 By default MACVLAN interface are in VEPA mode which filters out received packets whose MAC source address matches that of the MACVLAN interface. Setting MACVLAN interface in private mode will not filter based on source MAC address. Alternatively, you can specify 'vmac_xmit_base' which will cause the VRRP messages to be transmitted and received on the underlying interface whilst ARP will happen from the the VMAC interface. You may also need to tweak your physical interfaces to play around with well known ARP issues. If you have issues, try the following configurations : 1) Global configuration net.ipv4.conf.all.arp_ignore = 1 net.ipv4.conf.all.arp_announce = 1 net.ipv4.conf.all.arp_filter = 0 2) Physical interface configuration For the physical ethernet interface running VRRP instance use: net.ipv4.conf.eth0.arp_filter = 1 3) VMAC interface consider the following VRRP configuration : vrrp_instance instance1 { state BACKUP interface eth0 virtual_router_id 250 use_vmac vmac_xmit_base # Transmit VRRP adverts over physical interface priority 150 advert_int 1 virtual_ipaddress { 10.0.0.254 } } The 'use_vmac' keyword will drive keepalived code to create a macvlan interface named 'vrrp.250' (default internal paradigm is vrrp.{virtual_router_id}, you can override this naming by giving an argument to 'use_vmac' keyword, eg: use_vmac vrrp250). you then need to configure interface with : net.ipv4.conf.vrrp.250.arp_filter = 0 net.ipv4.conf.vrrp.250.accept_local = 1 (this is needed for the address owner case) net.ipv4.conf.vrrp.250.rp_filter = 0 you can create notify_master script to automate this configuration step for you : vrrp_instance instance1 { state BACKUP interface eth0 virtual_router_id 250 use_vmac priority 150 advert_int 1 virtual_ipaddress { 10.0.0.254 } notify_master "/usr/local/bin/vmac_tweak.sh vrrp.250" }