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Cisco ME 3800X and 3600X Switch Software Configuration Guide
OL-23400-01
Chapter 16 Configuring Resilient Ethernet Protocol
Configuring REP
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REP sends all LSL PDUs in untagged frames on the native VLAN. The BPA message sent to the
Cisco multicast address is sent on the administration VLAN, which is VLAN 1 by default.
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You can configure how long a REP interface remains up without receiving a hello from a neighbor.
You can use the rep lsl-age-timer value interface configuration command to set the time from
920 ms to 10000 ms. The LSL hello timer is then set to the age-timer value divided by three. In
normal operation, three LSL hellos are sent before the age timer on the peer switch expires and
searches for hello messages.
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If the REP neighbor device is running software earlier than Cisco IOS Release 12.2(52)SE, the
LSL age-timer range is from 3000 to 10000 ms in 500-ms increments. In that case, you must
use the shorter time range because the device will not accept values out of the previous range.
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EtherChannel port channel interfaces do not support LSL age-timer values less than 1000 ms.
If you try to configure a value less than 1000 ms on a port channel, you receive an error message
and the command is rejected.
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REP is supported on EtherChannels, but not on an individual port that belongs to an EtherChannel.
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There is a maximum of 64 REP segments per switch.
Configuring the REP Administrative VLAN
To avoid the delay introduced by relaying messages in software for link-failure or VLAN-blocking
notification during load balancing, REP floods packets at the hardware flood layer (HFL) to a regular
multicast address. These messages are flooded to the whole network, not just the REP segment. You can
control flooding of these messages by configuring an administrative VLAN for the whole domain.
Follow these guidelines when configuring the REP administrative VLAN:
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If you do not configure an administrative VLAN, the default is VLAN 1.
•
There can be only one administrative VLAN on a switch and on a segment. However, this is not
enforced by software.
Beginning in privileged EXEC mode, follow these steps to configure the REP administrative VLAN:
This example shows how to configure the administrative VLAN as VLAN 100 and to verify the
configuration by entering the show interface rep detail command on one of the REP interfaces:
Switch#
configure terminal
Switch (conf)#
rep admin vlan 100
Switch (conf-if)#
end
Command
Purpose
Step 1
configure terminal
Enter global configuration mode.
Step 2
rep admin vlan vlan-id
Specify the administrative VLAN. The range is 2 to 4094.
The default is VLAN 1. To set the admin VLAN to 1,
enter the no rep admin vlan global configuration
command.
Step 3
end
Return to privileged EXEC mode.
Step 4
show interface [interface-id] rep detail
Verify the configuration on one of the REP interfaces.
Step 5
copy running-config startup config
(Optional) Save your entries in the switch startup
configuration file.
