Concept Guide

Handling of Switch-Destined Trac
• The switch processes all trac 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 congured 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 trac 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 trac 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 trac is handled as per existing behavior by doing route lookup in the default routing table. So if the trac 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 trac 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 trac for such end-user-originated sessions destined to management port ip1 is handled using
the EIS route lookup.
Handling of Transit Trac (Trac Separation)
This is forwarded trac where destination IP is not an IP address congured 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, trac received in
the management port destined on the data port network is dropped and trac received in the front-end port destined on the management
network is dropped.
Mapping of Management Applications and Trac Type
The following table summarizes the behavior of applications for various types of trac when the management egress interface selection
feature is enabled.
Internet Group Management Protocol (IGMP)
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