Administrator Guide

Traffic type /
Application type
Switch initiated traffic Switch-destined traffic Transit Traffic
route lookup fails, packets are
dropped.
on route lookup in EIS table. If management port
is down or route lookup fails, packets are
dropped
management port is
blocked
Non-EIS
management
application
Front-end default route will take
higher precedence over
management default route and SSH
session to an unknown destination
uses the front-end default route
only. No change in the existing
behavior.
If source TCP/UDP port matches a
management application and the source IP
address is a management port IP address, the
management port is the preferred egress port
selected based on route lookup in EIS table. If
the management port is down or the route
lookup fails, packets are dropped
Traffic from management
port to data port and
from data port to
management port is
blocked
• EIS is enabled implies that EIS feature is enabled and the application might or might not be configured as a management application
• EIS is disabled implies that either EIS feature itself is disabled or that the application is not configured as a management application
Transit Traffic
This phenomenon occurs where traffic is transiting the switch. Traffic has not originated from the switch and is not terminating on the
switch.
• Drop the packets that are received on the front-end data port with destination on the management port.
• Drop the packets that received on the management port with destination as the front-end data port.
Switch-Destined Traffic
This phenomenon occurs where traffic is terminated on the switch. Traffic has not originated from the switch and is not transiting the
switch.
The switch accepts all traffic destined to the switch, which is received on management or front-end data port. Response traffic with
management port IP address as source IP address is handled in the same manner as switch originated traffic.
Switch-Originated Traffic
This phenomenon occurs where traffic is originating from the switch.
1. Management Applications (Applications that are configured as management applications):
The management port is an egress port for management applications. If the management port is down or the destination is not
reachable through the management port (next hop ARP is not resolved, and so on), and if the destination is reachable through a data
port, then the management application traffic is sent out through the front-end data port. This fallback mechanism is required.
2. Non-Management Applications (Applications that are not configured as management applications as defined by this feature):
Non-management application traffic exits out of either front-end data port or management port based on routing table. If there is a
default route on both the management and front-end data port, the default for the data port is preferred route.
Behavior of Various Applications for Switch-Initiated
Traffic
This section describes the different system behaviors that occur when traffic is originating from the switch:
EIS Behavior: If the destination TCP/UDP port matches a configured management application, a route lookup is done in the EIS table
and the management port gets selected as the egress port. If management port is down or the route lookup fails, packets are dropped.
EIS Behavior for ICMP: ICMP packets do not have TCP/UDP ports. To do an EIS route lookup for ICMP-based applications (ping and
traceroute) using the source ip option, the management port IP address should be specified as the source IP address. If management port
is down or route lookup fails, packets are dropped.
Default Behavior: Route lookup is done in the default routing table and appropriate egress port is selected.
Table 23. Behavior of Various Applications for Switch-Initiated Traffic
Protocol Behavior when EIS is Enabled Behavior when EIS is Disabled
dns EIS Behavior Default Behavior
296 Internet Group Management Protocol (IGMP)