User manual

Release Notes for Catalyst 6500 Series Content Switching Module Software Release 2.2(8)

78-12569-16

Caveats

The packet is dropped and the ICMP error is sent back to the host where the packet originated. This

action tells the originating host that it needs to reduce the size of its packets before they can be

routed.

Recent system implementations also include the MTU of the next hop in the ICMP message so that

the source knows how big its packets can be.

Workaround: Disable the path MTU discovery on the servers behind the CSM.

• 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.

This problem occurs when 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 physical MAC address on the active HSRP router, 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.

• CSCdw80718

Configuring a large number of client VLANs (each configured with its own gateway) can cause the

switch console to hang and the configuration performance to be extremely slow.

Workaround: Limit the number of client-side gateways configured to a small number (less than 10).