Datasheet

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Release Notes for Cisco IOS Release 12.1E on the Catalyst 6500 and Cisco 7600 Supervisor Engine and MSFC
OL-2310-11
Caveats
Resolved Caveats in Release 12.1(5c)E10
• When the active supervisor engine shuts down normally, it notifies the redundant supervisor engine
to switch over quicker. Occasionally, this notification fails, resulting in an infinite series of
SYS-2-INTSCHED messages. This problem is resolved in Releases 12.1(5c)E10 and 12.1(6)E1.
(CSCdt21103)
• Occasionally, the active supervisor engine fails to send clock updates to the redundant supervisor
engine, which hangs the heartbeat process on the active supervisor engine. This causes the system
to reload. This problem is resolved in Releases 12.1(5c)E10 and 12.1(6)E1. (CSCdt28184)
• With a large OSPF routing table, the MSFC might experience periods of high CPU utilization and
temporary loss of console communication when redistributing routes. This problem is resolved in
Releases 12.1(5c)E10 and 12.1(6)E1. (CSCdt71785)
Resolved Caveats in Release 12.1(5c)E9
• Maximum-sized packets sent to a tunnel interface on an MSFC2 cause a reload. To avoid the
problem, tunnel traffic is process switched in Release 12.1(5c)E9 and later. (CSCdt04991)
Resolved Caveats in Release 12.1(5c)E8
• Cisco Security Advisory:
Cisco IOS Software TCP Initial Sequence Number Randomization Improvements
Revision 1.0: INTERIM
For Public Release2001 February 27 20:00 US/Eastern (UTC+0500)
Summary:
Cisco IOS software contains a flaw that permits the successful prediction of TCP Initial Sequence
Numbers.
This vulnerability is present in all released versions of Cisco IOS software running on Cisco routers
and switches. It only affects the security of TCP connections that originate or terminate on the
affected Cisco device itself; it does not apply to TCP traffic forwarded through the affected device
in transit between two other hosts.
To remove the vulnerability, Cisco is offering free software upgrades for all affected platforms. The
defect is described in DDTS record CSCds04747.
Workarounds are available that limit or deny successful exploitation of the vulnerability by filtering
traffic containing forged IP source addresses at the perimeter of a network or directly on individual
devices. This notice will be posted at:
http://www.cisco.com/warp/public/707/ios-tcp-isn-random-pub.shtml. (CSCds04747)
• With an MSFC2, HSRP does not work on VLANs where PBR is configured. This problem is
resolved in Release 12.1(5c)E8. (CSCdt35971)
• PBR traffic from WAN interfaces is not Layer 3 switched in hardware. This problem is resolved in
Release 12.1(5c)E8. (CSCdt19985)