Specifications

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Cisco MWR 2941 Mobile Wireless Edge Router Software Configuration Guide, Release 12.2(33)MRB
OL-21227-02
Chapter 1 Cisco MWR 2941 Router Overview
Features
VLAN Load Balancing
One edge port in the REP segment acts as the primary edge port; the other as the secondary edge port.
The primary edge port always participates in VLAN load balancing in the segment. REP VLAN
balancing is achieved by blocking some VLANs at a configured alternate port and all other VLANs at
the primary edge port. When you configure VLAN load balancing, you can specify the alternate port in
one of three ways:
• Enter the port ID of the interface. To identify the port ID of a port in the segment, enter the show
interface rep detail interface configuration command for the port.
• Enter the neighbor offset number of a port in the segment, which identifies the downstream neighbor
port of an edge port. The neighbor offset number range is –256 to +256; a value of 0 is invalid. The
primary edge port has an offset number of 1; positive numbers above 1 identify downstream
neighbors of the primary edge port. Negative numbers identify the secondary edge port (offset
number –1) and its downstream neighbors.
Note You configure offset numbers on the primary edge port by identifying the downstream position
from the primary (or secondary) edge port. You would never enter an offset value of 1 because
that is the offset number of the primary edge port itself.
Figure 1-4 shows neighbor offset numbers for a segment where E1 is the primary edge port and E2 is
the secondary edge port. The red numbers inside the ring are numbers offset from the primary edge port;
the black numbers outside the ring show the offset numbers from the secondary edge port. Note that you
can identify all ports (except the primary edge port) by either a positive offset number (downstream
position from the primary edge port) or a negative offset number (downstream position from the
secondary edge port). If E2 became the primary edge port, its offset number would then be 1,
and E1 would be -1.
• By entering the preferred keyword to select the port that you previously configured as the preferred
alternate port with the rep segment segment-id preferred command in interface configuration
mode.
Figure 1-4 Neighbor Offset Numbers in a Segment
When the REP segment is complete, all VLANs are blocked. When you configure VLAN load balancing,
you must also configure triggers in one of two ways
• Manually trigger VLAN load balancing at any time by entering the rep preempt segment
segment-id privileged EXEC command on the switch that has the primary edge port.
E2E1
-1
-2
-3
-4
-5
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-7
-8
-9
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1
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201890
E1 = Primary edge port
E2 = Secondary edge port
Offset numbers from the primary edge port
Offset numbers from the secondary edge
port (negative numbers)