With the Equal Cost Multiple Path (ECMP) mechanism, virtual server IP addresses are advertised by all active cluster nodes. This means that traffic can be received by any cluster node, which then steers the traffic to the node that must process the traffic. There can be redundant steering in case of spotted and partially striped virtual servers. Therefore, from NetScaler 11 onwards, spotted and partially striped virtual server IP addresses are advertised only by the owner nodes. This reduces the redundant steering.
To use ECMP, you must first enable the required routing protocol (OSPF, RIP, BGP, or ISIS) on the cluster IP address. You must bind the interfaces and the spotted IP address (with dynamic routing enabled) to a VLAN. Configure the selected routing protocol and redistribute the kernel routes on the ZebOS by using the vtysh shell.
You must perform similar configurations on the cluster IP address and on the external connecting device.
Make sure that the licenses on the cluster support dynamic routing, otherwise ECMP does not work.
ECMP is not supported for wildcard virtual servers since RHI needs a VIP address to advertise to a router and wildcard virtual servers do not have associated VIP addresses.
As seen in the above figure, the ECMP router can reach the VIP address via SNIP0, SNIP1, or SNIP2.
enable ns feature <feature>Example: To enable the OSPF routing protocol.
> enable ns feature ospf
add vlan <id>Example
> add vlan 97
bind vlan <id> -ifnum <interface_name>Example
> bind vlan 97 -ifnum 0/1/2 1/1/2 2/1/2
add ns ip <SNIP> <netmask> -ownerNode <positive_integer> -dynamicRouting ENABLEDExample
> add ns ip 22.214.171.124 255.0.0.0 -ownerNode 0 -dynamicRouting ENABLED -type SNIP
> add ns ip 126.96.36.199 255.0.0.0 -ownerNode 1 -dynamicRouting ENABLED -type SNIP
> add ns ip 188.8.131.52 255.0.0.0 -ownerNode 2 -dynamicRouting ENABLED -type SNIP
bind vlan <id> -IPAddress <SNIP> <netmask>Example
> bind vlan 97 -ipAddress 184.108.40.206 255.0.0.0
Example: To configure OSPF routing protocol on node IDs 0, 1, and 2.
> vtysh ! interface vlan97 ! router ospf owner-node 0 ospf router-id 220.127.116.11 exit-owner-node owner-node 1 ospf router-id 18.104.22.168 exit-owner-node owner-node 2 ospf router-id 22.214.171.124 exit-owner-node redistribute kernel network 126.96.36.199/8 area 0 !
add ns ip <IPAddress> <netmask> -type VIP -vserverRHILevel <vserverRHILevel>
For OSPF specific RHI settings, there are additional settings that can be done as follows:
add ns ip <IPAddress> <netmask> -type VIP -ospfLSAType ( TYPE1 | TYPE5 ) -ospfArea <positive_integer>
//For OSPF (IPv4 addresses) Global config: Configure terminal feature ospf Interface config: Configure terminal interface Vlan10 no shutdown ip address 188.8.131.52/8 Configure terminal router ospf 1 network 184.108.40.206/8 area 0.0.0.0 --------------------------------- //For OSPFv3 (IPv6 addresses) Global config: Configure terminal feature ospfv3 Configure terminal interface Vlan10 no shutdown ipv6 address use-link-local-only ipv6 router ospfv3 1 area 0.0.0.0 Configure terminal router ospfv3 1