Installation Guide

IBR Installation Guide
Page 34 of 38 Doc # 770-00023.1
Jan. 23, 2015
By default, all IBR Ethernet ports are assigned natively to VLAN1. To avoid creating a loop, configure a trunk
native interface on gigabit Ethernet 3 as shown in the following example:
IBR101 (config) # interface vlan 2
IBR101 (config-vlan2) # no shutdown
IBR101 (config-vlan2) # exit
IBR101 (config) # interface gigabitEthernet 3
IBR101 (config-if-ge3)# no switchport trunk native vlan 1
IBR101 (config-if-ge3) # switchport trunk native vlan 2
IBR101 (config-if-ge3) # do copy running-config startup-config
It is necessary to perform this setup on only one side of the link, unless there is untagged traffic on the link, in
which case it should be performed on both sides of the link.
Network loops also can be avoided by creating a separate management interface on each IBR. See the IBR
Administration & Command Line Interface Guide for information about creating a management interface.
Return to Table of Contents
A 4. Link Is Established But Not Passing Traffic
Confirm that a link has been established by (i) pinging the opposite end, (ii) checking the interface counters,
and/or (iii) viewing the radio link status using the following command:
IBR101 # show interface radio 0 status
If a link has been established, but will not pass traffic, do the following:
a. Confirm that IBR is configured to pass all VLAN traffic, regardless of VLAN, by using the bridge
command as shown below.
IBR101 (config) # bridge linklocalframes gigabitethernet 1
Do this on both sides of the link using the connected data port on VLAN2 which, in this case, is ge1.
b. Check syslog for messages that indicate that the link is going up and down.
IBR101 # show logging active
NOTE: Use Ctrl-C to stop the display from continuing to scroll.
c. Confirm that MTU is set correctly on both IBRs.
IBR101 (config) # mtu 9712
NOTE: When MTU is set to 9712, it will be 9712 between the wired switch ports; however, the over-
the-air MTU is limited to 2599.
d. Check history logs for radio conditions prior to the time when the link would not pass traffic.
IBR101 # show interface radio 0 history mcs
IBR101 # show interface radio 0 history bler
If history shows that MCS dropped to 1 and BLER increased before the link stopped passing traffic, the
cause might be interference.
Return to Table of Contents
A 5. IBR Cannot Be Reached Via the Network
Follow these steps if IBR cannot be reached via the network.