Citrix ByteMobile T1010, Установка, настройка и администрирование

Страница: 108 / 172

4-4 T-Series Traffic Director Installation, Configuration and Administration Guide
Chapter 4 Dynamic Routing Protocol Configuration for T 1000/Unison
Configuring T1000 for OSPF
The procedure in this section assumes the T1000s are already configured in High
Availability mode. In case of failure, the new primary node injects all its VIP routes into the
upstream router. However, that router retains the old primary node’s routes for 180 seconds.
Because the router is not aware of the failover, it attempts to load balance traffic between the
two nodes. During the 180 seconds before the old routes expire, the router sends half the
traffic to the old, inactive primary node, which is, in effect, a black hole. To prevent this, the
new primary node, when injecting a route, assigns it a metric that is slightly lower than the
one specified by the old primary node.
To configure the OSPF feature on the T1000 appliances with an IP address in a subnet other
than that of the NSIP address, applying the following command sequence from the CLI of
each T1000:
> enable ns feature OSPF
Done
> set ns ip 172.16.124.101 -dynamicRouting ENABLED
Done
> set ns ip 172.16.125.101 -dynamicRouting ENABLED
Done
Note: When dynamic routing is enabled as shown (with vserver-specific MAC and
two vservers per traffic domain on ingress and egress), OSPF may only be used
on the ingress side. On the egress side, the Internet router is bound as a service
to the egress vserver, and traffic will be directly forwarded to it without
checking the routing table entries. This issue will be resolved in a subsequent
release.
After enabling the OSPF, you can configure it by using the vtysh shell
> Vtysh
T1000-1#
T1000-1# conf t
T1000-1(config-router)# router ospf 100
T1000-1(config-router)# redistribute kernel
T1000-1(config-router)# network 172.16.124.101 0.0.0.0 area 0
T1000-1(config-router)# network 172.16.125.101 0.0.0.0 area 0
The T1000 can use routes learned by various routing protocols after you install the routes in
the node's routing table
> Vtysh
T1000-1#
T1000-1# conf t
T1000-1(config)# ns route-install ospf
T1000-1(config)#
ns route-install default
If HA pair has different next hops, the nodes will learn two different routes for client
network and on failover there will be an outage because the old primary T1000’s route will
be retained for 180 seconds. To eliminate this issue, nodes must be in HA-INC (High
Availability - Independent Network Configuration) mode where network configuration,
including OSPF, has to be done separately on the two appliances. Although it costs new IP
addresses, routes are not synced from Primary to Secondary and downtime on a failover is
estimated between 2-3 seconds.