Cisco Cisco IOS Software Release 15.0(1)SE Release Notes
8
Release Notes for the Cisco IE 3010 Switch, Cisco IOS Release 15.0(2)SE and Later
OL-27309-02
Limitations and Restrictions
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When you enter the boot host retry timeout global configuration command to specify the amount
of time that the client should keep trying to download the configuration and you do not enter a
timeout value, the default value is zero, which should mean that the client keeps trying indefinitely.
However, the client does not keep trying to download the configuration.
of time that the client should keep trying to download the configuration and you do not enter a
timeout value, the default value is zero, which should mean that the client keeps trying indefinitely.
However, the client does not keep trying to download the configuration.
The workaround is to always enter a non-zero value for the timeout value when you enter the boot
host retry timeout timeout-value command. (CSCsk65142)
host retry timeout timeout-value command. (CSCsk65142)
•
On a switch running both Resilient Ethernet Protocol (REP) and Bidirectional Forwarding Detection
(BFD), when the REP link status layer (LSL) age-out value is less than 1 second, the REP link flaps
if the BFD interface is shut down and then brought back up.
(BFD), when the REP link status layer (LSL) age-out value is less than 1 second, the REP link flaps
if the BFD interface is shut down and then brought back up.
The workaround is to use the rep lsl-age-out timer interface configuration command to configure
the REP LSL age timer for more than 1000 milliseconds (1 second). (CSCsz40613)
the REP LSL age timer for more than 1000 milliseconds (1 second). (CSCsz40613)
Ethernet
Traffic on EtherChannel ports is not perfectly load-balanced. Egress traffic on EtherChannel ports is
distributed to member ports on a load-balance configuration, and traffic characteristics such as MAC or
IP address.
distributed to member ports on a load-balance configuration, and traffic characteristics such as MAC or
IP address.
More than one traffic stream might map to same member ports based on hashing results calculated by
the ASIC. If this happens, uneven traffic distribution happens on EtherChannel ports.
the ASIC. If this happens, uneven traffic distribution happens on EtherChannel ports.
Changing the load-balance distribution method or changing the number of ports in the EtherChannel can
resolve this problem.
resolve this problem.
Use any of these workarounds to improve EtherChannel load balancing:
•
For random source-ip and dest-ip traffic, configure the load-balance method as src-dst-ip.
•
For incrementing source-ip traffic, configure the load-balance method as src-ip.
•
For incrementing dest-ip traffic, configure the load-balance method as dst-ip.
•
Configure the number of ports in the EtherChannel so that the number is equal to a power of 2 (that
is, 2, 4, or 8)
is, 2, 4, or 8)
For example, with load balance configured as dst-ip with 150 distinct incrementing destination IP
addresses, and the number of ports in the EtherChannel set to either 2, 4, or 8, load distribution is
optimal. (CSCeh81991)
addresses, and the number of ports in the EtherChannel set to either 2, 4, or 8, load distribution is
optimal. (CSCeh81991)
IP
When the rate of received DHCP requests
exceeds 2,000 packets per minute for a long time, the response
time might be slow when you are using the console.
The workaround is to use rate limiting on DHCP traffic to prevent a denial of service attack from
occurring. (CSCeb59166)
occurring. (CSCeb59166)
QoS
•
Some switch queues are disabled if the buffer size or threshold level is set too low with the mls qos
queue-set output global configuration command. The ratio of buffer size to threshold level should
be greater than 10 to avoid disabling the queue.
queue-set output global configuration command. The ratio of buffer size to threshold level should
be greater than 10 to avoid disabling the queue.
The workaround is to choose compatible buffer sizes and threshold levels. (CSCea76893)