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Learned Dynamically: Routing protocols can learn ECMP routes. For
example, if OSPF is configured on both links connecting Router A to
Router B with interface addresses 10.1.1.2 and 10.1.2.2 respectively, and
Router B advertises its connection to 20.0.0.0/ 8, then Router A computes
an OSPF route to 20.0.0.0/8 with next hops of 10.1.1.2 and 10.1.2.2.
Dell EMC Networking routing stores static and dynamic routes in a single
combined routing table. RTO accepts ECMP routes, but it is important to
understand that RTO does not combine routes from different sources to
create ECMP routes. Referring to the above configuration, assume OSPF is
only configured on the 10.1.1.2 Router B interface connecting Router A and
Router B. Then on Router A, OSPF reports to RTO a route to 20.0.0.0/8 with
a next hop of 10.1.1.2. If the user configures a static route to 20.0.0.0/8 with a
single next hop of 10.1.2.2, RTO does NOT combine the OSPF and static
route into a single route to 20.0.0.0/8 with two next hops. All next hops within
an ECMP route must be provided by the same source.
On Dell EMC Networking N3000, N3100, and N4000 platforms, the ECMP
hashing support utilizes Enhanced hashing mode, which provides improved
load-balancing performance. ECMP hashing on these platforms has the
following features:
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MODULO-N operation based on the number N of next hops in the route.
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Packet attributes selection based on the packet type. For IP packets, the
following fields are used: Source IP address, Destination IP address,
TCP/UDP port, IPv4 Protocol, IPv6 next header.
Forwarding of OSPF Opaque LSAs Enabled by
Default
Dell EMC Networking supports the flooding capability of opaque LSAs. Dell
EMC Networking cannot originate or process opaque LSAs. In the past, the
capability to flood opaque LSAs was disabled by default.
Passive Interfaces
The passive interface feature is used to disable sending OSPF routing updates
on an interface. An OSPF adjacency will not be formed on such an interface.
On a passive interface, subnet prefixes for IP addresses configured on the
interface will continue to be advertised as stub networks.
Layer 3 Routing Commands
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