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● Because fallback support is removed, if the management port is down or the route lookup in EIS table fails packets are
dropped. Therefore, switch-initiated traffic sessions that used to work previously via fallback may not work now.
Handling of Switch-Destined Traffic
● The switch processes all traffic received on the management port destined to the management port IP address or the
front-end port destined to the front-end IP address.
● If the source TCP/UDP port number matches a configured EIS or non-EIS management application and the source IP
address is a management Port IP address, then the EIS route lookup is done for the response traffic and hence is sent out
of the management port. In this case, the source IP address is a management port IP address only if the traffic was originally
destined to the management port IP.
● ICMP-based applications like ping and traceroute are exceptions to the preceding logic since we do not have TCP/UDP port
number. So if source IP address of the packet matches the management port IP address EIS route lookup is done.
● Management application packet counter is incremented if EIS route lookup succeeds and packet is sent out of the
management port.
● If route lookup in the EIS routing table fails or if the management port is down, then packets are dropped. The management
application drop counter is incremented.
● Whenever IP address is assigned to the management port, it is stored in a global variable in the IP stack, which is used for
comparison with the source IP address of the packet.
● Rest of the response traffic is handled as per existing behavior by doing route lookup in the default routing table. So if the
traffic is destined to the front-end port IP address, the response is sent out by doing a route lookup in the default routing
table, which is an existing behavior.
Consider a sample topology in which ip1 is an address assigned to the management port and ip2 is an address assigned to any
of the front panel port. A and B are end users on the management and front-panel port networks. The OS-initiated traffic for
management applications takes a preference for ip1 as source IP and uses the management network to reach the destination.
If the management port is down or the route lookup in EIS routing table fails, ip2 is the source IP and the front-panel port
is used to reach the destination. The fallback route between the management and data networks is used in such a case. At
any given time, end users can access Dell EMC Networking OS applications using either ip1 or ip2. Return traffic for such
end-user-originated sessions destined to management port ip1 is handled using the EIS route lookup.
Handling of Transit Traffic (Traffic Separation)
This is forwarded traffic where destination IP is not an IP address configured in the switch.
● Packets received on the management port with destination on the front-end port is dropped.
● Packets received on the front-end port with destination on the management port is dropped.
● A separate drop counter is incremented for this case. This counter is viewed using the netstat command, like all other IP
layer counters.
Consider a scenario in which ip1 is an address assigned to the management port and ip2 is an address assigned to any of
the front panel port of a switch. End users on the management and front panel port networks are connected. In such an
environment, traffic received in the management port destined on the data port network is dropped and traffic received in the
front-end port destined on the management network is dropped.
Mapping of Management Applications and Traffic Type
The following table summarizes the behavior of applications for various types of traffic when the management egress interface
selection feature is enabled.
Internet Group Management Protocol (IGMP)
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