HP Cisco Catalyst Blade Switch 3020 Release Notes for Cisco Catalyst Blade Swi - Page 8

Ethernet, IP, IP Telephony, switchport block unicast, interface, boot host retry timeout, src-dst-ip

Page 8 highlights

Limitations and Restrictions Ethernet IP IP Telephony • When port security is enabled on an interface in restricted mode and the switchport block unicast interface command has been entered on that interface, MAC addresses are incorrectly forwarded when they should be blocked The workaround is to enter the no switchport block unicast interface configuration command on that specific interface. (CSCee93822) • A traceback error occurs if a crypto key is generated after an SSL client session. There is no workaround. This is a cosmetic error and does not affect the functionality of the switch. (CSCef59331) • 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. 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) • Traffic on EtherChannel ports is not perfectly load-balanced. Egress traffic on EtherChannel ports are distributed to member ports on load balance configuration and traffic characteristics like 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, traffic distribution is uneven on EtherChannel ports. Changing the load balance distribution method or changing the number of ports in the EtherChannel can resolve this problem. Use any of these workarounds to improve EtherChannel load balancing: - for random source-ip and dest-ip traffic, configure load balance method as src-dst-ip - for incrementing source-ip traffic, configure load balance method as src-ip - for incrementing dest-ip traffic, configure 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 (for example, 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) • 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) • After you change the access VLAN on a port that has IEEE 802.1x enabled, the IP phone address is removed. Because learning is restricted on IEEE 802.1x-capable ports, it takes approximately 30 seconds before the address is relearned. No workaround is necessary. (CSCea85312) Release Notes for the Cisco Catalyst Blade Switch 3020 for HP, Cisco IOS Release 12.2(50)SE and Later 8 OL-18274-02

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8
Release Notes for the Cisco Catalyst Blade Switch 3020 for HP, Cisco IOS Release 12.2(50)SE and Later
OL-18274-02
Limitations and Restrictions
When port security is enabled on an interface in restricted mode and the
switchport block unicast
interface
command has been entered on that interface, MAC addresses are incorrectly forwarded
when they should be blocked
The workaround is to enter the
no switchport block unicast
interface configuration command on
that specific interface. (CSCee93822)
A traceback error occurs if a crypto key is generated after an SSL client session.
There is no workaround. This is a cosmetic error and does not affect the functionality of the switch.
(CSCef59331)
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.
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)
Ethernet
Traffic on EtherChannel ports is not perfectly load-balanced. Egress traffic on EtherChannel ports
are distributed to member ports on load balance configuration and traffic characteristics like 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, traffic distribution is uneven on EtherChannel ports.
Changing the load balance distribution method or changing the number of ports in the EtherChannel
can resolve this problem. Use any of these workarounds to improve EtherChannel load balancing:
for random source-ip and dest-ip traffic, configure load balance method as
src-dst-ip
for incrementing source-ip traffic, configure load balance method as
src-ip
for incrementing dest-ip traffic, configure 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
(for example, 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)
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)
IP Telephony
After you change the access VLAN on a port that has IEEE 802.1x enabled, the IP phone address is
removed. Because learning is restricted on IEEE 802.1x-capable ports, it takes approximately 30
seconds before the address is relearned. No workaround is necessary. (CSCea85312)