User manual

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Release Notes for Catalyst 6500 Series Content Switching Module Software Release 2.2(8)
78-12569-16
Caveats
• CSCdx17864
When Layer 7 features are enabled on the CSM, the CSM may drop the IP frames it receives if those
frames contain multiple IP options. The following features require Layer 7 functionality: URL
regular expression matching, cookie regular expression matching, cookie sticky, URL hash sticky,
SSL ID sticky, and generic HTTP header parsing. This issue exists in the following CSM releases:
1.x, 2.1(1), 2.1(2), 2.1(3) 2.2(1), 2.2(2).
Workaround: Multiple IP options are not common in networks, but you can disable the Layer 7
features if this issue causes a problem.
• CSCdx16168
Due to internal optimizations that improve overall network throughput, the CSM must listen to the
HSRP protocol signalling to properly learn the HSRP virtual MAC address that is shared between
the active and standby HSRP routers.
The caveat is that the HSRP learning code in the CSM assumes that any given HSRP group appears
on only one VLAN. If the same HSRP group appears on two different VLANs, the HSRP virtual
MAC for the group is learned for only one of these VLANs.
If the CSM does not properly learn the HSRP virtual MAC address, the following symptoms may
occur:
– Connections are dropped when coming from the HSRP router through the CSM.
– The CSM sends frames to the active HSRP router's physical MAC address, not the HSRP virtual
MAC address.
– If connection redundancy is enabled between two CSMs, connections may take an unusually
long time to be replicated from the active to the standby CSM.
Workaround: Change HSRP group numbers to be globally unique.
Resolved Caveats in Software Release 2.1(3)
This section describes caveats that have been resolved in CSM software release 2.1(3).
• CSCdw41620
The CSM may classify incoming frames incorrectly, causing those frames to be dropped. Such
packet loss results in intermittent connectivity to virtual servers configured on the CSM. This
problem occurs only if 128 or more virtual servers have been configured on the device since bootup.
(This number includes virtual servers that have been configured and subsequently removed from the
configuration.) In most production scenarios, virtual servers are configured only when the device
boots.
This defect is present in CSM software releases 1.1(1), 1.2(1), 2.1(1), 2.1(2). This defect is fixed in
version 1.2(1).
• CSCdw47545
DNS probes are always failing, thus taking the servers out of service. The CSM considers the probe
reply to be an incorrect reply, even when the returned IP address matches the configured expected
IP address.
• CSCdw48046
When using the destination IP address hash predictor, the CSM reassigns connections from a failed
or out-of-service server to the next in-service server. In cases where multiple contiguous servers fail
or are taken out-of-service, too many connections may be reassigned to the next in-service server.