Datasheet

197
Release Notes for Cisco IOS Release 12.1E on the Catalyst 6500 and Cisco 7600 Supervisor Engine and MSFC
OL-2310-11
Caveats
• With Rapid-Per-VLAN-Spanning Tree (Rapid-PVST) or IEEE 802.1s multiple spanning tree (MST)
configured, when the root bridge in a spanning tree domain ages out, the remaining bridges
reconverge after timing out the root bridge. During this reconvergence, a spanning tree loop might
occur. This problem is resolved in Release 12.1(20)E2. (CSCed00441)
• The PFC might not be programmed to provide Layer 3 switching for traffic that follows a static route
to the null 0 interface. This problem is resolved in Release 12.1(20)E2. (CSCea86396)
• A vulnerability in the Transmission Control Protocol (TCP) specification (RFC793) has been
discovered by an external researcher. The successful exploitation enables an adversary to reset any
established TCP connection in a much shorter time than was previously discussed publicly.
Depending on the application, the connection may get automatically re-established. In other cases,
a user will have to repeat the action (for example, open a new Telnet or SSH session). Depending
upon the attacked protocol, a successful attack may have additional consequences beyond
terminated connection which must be considered. This attack vector is only applicable to the
sessions which are terminating on a device (such as a router, switch, or computer) and not to the
sessions that are only passing through the device (for example, transit traffic that is being routed by
a router). In addition, this attack vector does not directly compromise data integrity or
confidentiality.
All Cisco products which contain TCP stack are susceptible to this vulnerability.
This advisory is available at
http://www.cisco.com/warp/public/707/cisco-sa-20040420-tcp-ios.shtml, and it describes this
vulnerability as it applies to Cisco products that run Cisco IOS® software.
A companion advisory that describes this vulnerability for products that do not run Cisco IOS
software is available at
http://www.cisco.com/warp/public/707/cisco-sa-20040420-tcp-nonios.shtml.
This problem is resolved in Release 12.1(20)E2. (CSCed27956, CSCed38527)
• In releases where caveat CSCdz27200 is resolved, a reload might occur when you append a file
whose size is not a multiple of 512 bytes to an Advanced Technology Attachment (ATA) flash card
(for example, disk0). For example, this situation may occur when you enter the show
command_name | tee /append url privileged EXEC command. This problem is resolved in
Release 12.1(20)E2. (CSCin57765)
• When a Border Gateway Protocol (BGP) process propagates routes that are learned from an interior
Border Gateway Protocol (iBGP) peer to an external BGP (eBGP) peer, the eBGP peer should see
these routes with the next-hop address of the originator’s address, but the eBGP peer incorrectly sees
the routes with the next-hop address of the router that propagates the routes instead of the router that
originates the routes. This problem is resolved in Release 12.1(20)E2. (CSCed15277)
• To avoid dropping into ROMMON, do not insert a WS-X6816-GBIC that does not have a DFC
installed. This problem is resolved in Release 12.1(20)E2. (CSCed14506)
• Occasionally, the nvram:/startup-config file cannot be read. This problem is resolved in
Release 12.1(20)E2. (CSCed06462)
• Directly connected multicast enabled subnets might not be programmed correctly into the PFC. This
problem is resolved in Release 12.1(20)E2. (CSCed00394)
• L3-PS-DRVR messages are seen every 12 to 16 seconds. This problem is resolved in
Release 12.1(20)E2. (CSCec63833)
• With VLAN aging configured, the routed MAC (RM) bit might be set on the Layer 2 entries for
routed traffic, which causes the entries to be purged every 5 minutes. One packet might be flooded
and relearned for each purged entry. This problem is resolved in Release 12.1(20)E2. (CSCec43605)