Cisco Cisco IOS Software Release 12.4(4)T
1083
Caveats for Cisco IOS Release 12.4T
OL-8003-09 Rev. Z0
Resolved Caveats—Cisco IOS Release 12.4(9)T7
Conditions: This symptom is observed on a Cisco 7200-G2 router with a VSA card, acting as an
IPSec HUB, terminating EasyVPN DVTI remote-access IPSec tunnels into VRFs. At high tunnel
scale (more than 1000 tunnels), the CPU can spike close to 100 percent during IKE and/or IPSec
rekey, potentially causing traffic and tunnels to drop.
IPSec HUB, terminating EasyVPN DVTI remote-access IPSec tunnels into VRFs. At high tunnel
scale (more than 1000 tunnels), the CPU can spike close to 100 percent during IKE and/or IPSec
rekey, potentially causing traffic and tunnels to drop.
Workaround: Do not use more than 1000 RA EasyVPN DVTI tunnels on a Cisco 7200. Or switch to
Legacy EasyVPN tunnels (with dynamic crypto maps).
Legacy EasyVPN tunnels (with dynamic crypto maps).
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CSCsk99530
Symptoms: The MPLS forwarding table has an untagged outgoing entry for a VPNv4 prefix in a
CSC case.
CSC case.
Conditions: This is an LDP/IGP (OSPF etc.) based CSC-PE. The VPNv4 prefix shall have a
local/redistributed (PE-CE OSPF etc.) path as well as an iBGP path. If the CE path is toggled and
then there is a LABEL ONLY change from the iBGP neighbor, the issue will be seen. BGP will end
up programming “Untagged” for the local/redistributed prefix, overwriting what is given by LDP.
local/redistributed (PE-CE OSPF etc.) path as well as an iBGP path. If the CE path is toggled and
then there is a LABEL ONLY change from the iBGP neighbor, the issue will be seen. BGP will end
up programming “Untagged” for the local/redistributed prefix, overwriting what is given by LDP.
Workaround: There is no real workaround. To clear the problem, issue a clear ip route command
for the vrf-prefix in question. If there are redundant paired PEs, make sure to clear the problem on
both routers with the clear ip route command.
for the vrf-prefix in question. If there are redundant paired PEs, make sure to clear the problem on
both routers with the clear ip route command.
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CSCsl14635
Symptoms: T38 negotiation is failing for an incoming UPDATE request that has a T38 offer.
Conditions: This symptom occurs when the voice gateway is running Cisco IOS Release 12.4(15)T
and is processing incoming Session Initiation Protocol (SIP) calls. When the SIP call is active and
an UPDATE request is received that contains a T38 offer, the UPDAE request is rejected. The
switchover from voice to fax fails.
and is processing incoming Session Initiation Protocol (SIP) calls. When the SIP call is active and
an UPDATE request is received that contains a T38 offer, the UPDAE request is rejected. The
switchover from voice to fax fails.
Workaround: Fax over T38 works fine when midcall INVITE is used for T38 negotiation.
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CSCsl32308
Symptoms: A voice gateway may modify the Presentation Indicator (PI) field when processing a
voice call.
voice call.
Conditions: The voice gateway is running Cisco IOS Release 12.4(9)T5 and processing incoming
Session Initiation Protocol (SIP) calls. An incoming SIP call that has its PI field Oct 3a set to 0xA0
or to any other value is changed to 0x00 for no apparent reason when it is forwarded to the Telephony
call leg.
Session Initiation Protocol (SIP) calls. An incoming SIP call that has its PI field Oct 3a set to 0xA0
or to any other value is changed to 0x00 for no apparent reason when it is forwarded to the Telephony
call leg.
Workaround: There is no workaround.
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CSCuk60363
Symptoms: When Enhanced Compressed Real-Time Transport Protocol (ECRTP) is configured and
when multiple packet drops occur, cRTP packets may stop being sent, and only cUDP packets are
sent instead. Because cUDP packets are nearly as large as uncompressed packets, compression
becomes completely inefficient.
when multiple packet drops occur, cRTP packets may stop being sent, and only cUDP packets are
sent instead. Because cUDP packets are nearly as large as uncompressed packets, compression
becomes completely inefficient.
Conditions: This symptom is observed on a Cisco router when ECRTP is configured on an interface
and when a few packet drops occur, as in the following configuration example:
and when a few packet drops occur, as in the following configuration example:
interface Serial2/0
ip address x.x.x.x x.x.x.x
ip rtp header-compression ietf
ip header-compression recoverable-loss 1
Workaround: There is no workaround.