Cisco Cisco IOS Software Release 12.0 S Release Notes
1654
Cross-Platform Release Notes for Cisco IOS Release 12.0S
OL-1617-14 Rev. Q0
Resolved Caveats—Cisco IOS Release 12.0(25)S2
Conditions: This symptom is observed if the IP checksum is calculated with a decreased time-to-live
(TTL) value. For example, in the situation where the IP checksum must be 0x1134 with a TTL of 3,
if the packet is sent with an IP checksum of 0x1234 that is calculated by using a TTL value of 2, the
packet is not dropped. In all other cases, packets with incorrect checksums are dropped.
(TTL) value. For example, in the situation where the IP checksum must be 0x1134 with a TTL of 3,
if the packet is sent with an IP checksum of 0x1234 that is calculated by using a TTL value of 2, the
packet is not dropped. In all other cases, packets with incorrect checksums are dropped.
Workaround: There is no workaround.
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CSCec16481
A Cisco device running Internetwork Operating System (IOS) and enabled for the Open Shortest
Path First (OSPF) Protocol is vulnerable to a Denial of Service (DoS) attack from a malformed
OSPF packet. The OSPF protocol is not enabled by default.
Path First (OSPF) Protocol is vulnerable to a Denial of Service (DoS) attack from a malformed
OSPF packet. The OSPF protocol is not enabled by default.
The vulnerability is only present in IOS release trains based on 12.0S, 12.2, and 12.3. Releases based
on 12.0, 12.1 mainlines and all IOS images prior to 12.0 are not affected. Refer to the Security
Advisory for a complete list of affected release trains.
on 12.0, 12.1 mainlines and all IOS images prior to 12.0 are not affected. Refer to the Security
Advisory for a complete list of affected release trains.
Further details and the workarounds to mitigate the effects are explained in the Security Advisory
which is available at the following URL:
which is available at the following URL:
.
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CSCin51310
Symptoms: You may not be able to configure the ip vrf receive interface configuration command.
Conditions: This symptom is observed when the interface on which you attempt to configure the ip
vrf receive interface configuration command does not have an IP address configured.
vrf receive interface configuration command does not have an IP address configured.
Workaround: First configure an IP address on the interface, then enter the ip vrf receive interface
configuration command on the interface.
configuration command on the interface.
ISO CLNS
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CSCeb25498
Symptoms: A Cisco 10720 may reload unexpectedly.
Conditions: This symptom is observed when IP version 6 (IPv6) Intermediate
System-to-Intermediate System (IS-IS) is configured.
System-to-Intermediate System (IS-IS) is configured.
Workaround: There is no workaround.
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CSCeb72224
Symptoms: A Cisco router that is running Intermediate System-to-Intermediate System (IS-IS) may
not unset the IS-IS overload bit after a redundancy switchover, preventing the IS-IS connectivity
from being restored.
not unset the IS-IS overload bit after a redundancy switchover, preventing the IS-IS connectivity
from being restored.
Conditions: This symptom is observed on a Cisco router that has two Route Processors (RPs) in a
redundant configuration.
redundant configuration.
Workaround: To restore the IS-IS connectivity, and to prevent the symptom from occurring again,
enter the no set-overload-bit on-startup router configuration command on the primary RP.
enter the no set-overload-bit on-startup router configuration command on the primary RP.
Miscellaneous
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CSCdx59391