Cisco 7500 Series Routers

Field Notice: Cisco IOS release 11.1(19)CC Deferral (CSCdk10629)

Updated June 4, 1998

May 29, 1998

Products Affected

Table 1: Products affected by Cisco IOS deferral



Cisco 7500 Series





Cisco 7200 Series




Cisco IOS Versions Affected

Table 2: The Cisco IOS Software revisions below are affected by CSCdk08772.

Major/ED Release

Maintenance/Interims Affected


11.1(18.1)CC - 11.1(19)CC

Problem Description

When configured with OSPF, EIGRP, or STUN along with Weighted Fair Queuing (WFQ), hello packets are being dropped because of hashed queues function in Cisco IOS. Distributed WFQ (DWFQ) is not affected.

Note:?WFQ is on by default for physical interfaces with bandwidths less than or equal to 2.048Mbps and that do not use Link Access Procedure, Balanced (LAPB), X.25, PPP, or Synchronous Data Link Control (SDLC) encapsulations.

Bug Details

CSCdk10629 has been opened for the symptom stated above and has been marked a duplicate of CSCdj95348. The actual software defect was introduced in CSCdj77694.

Cisco Bug ID CSCdj77694 (registered customers only) - Packets out of sequence with WFQ.

Cisco Bug ID CSCdk10629 (registered customers only) - EIGRP: HELLO pkts could not go out on HSSI/4T with fair queue on.

Cisco Bug ID CSCdj95348 (registered customers only) - STUN basic doesnt pass data when direct is configured

Problem Symptoms

Neighbors will not see the router that is affected by CSCdk10629 because the hello packets are dropped from the affected router. The router affected will see its neighbors. The show ip eigrp neighbor command can be used to view the neighbors. For example, the command output below shows one neighbor:

router#sh ip eigrp nei
IP-EIGRP neighbors for process 1 
H   Address                 Interface   Hold Uptime   SRTT   RTO  Q  Seq 
                                        (sec)         (ms)       Cnt Num 
0               Fa2/0         13 00:00:05 1389  5000  0  2 


Turn off WFQ using the no fair interface command, as shown below:

router(interface)#no fair


To eliminate the problem mentioned in the preceding sections, Cisco strongly recommends that you download and install one of the Cisco IOS software release updates listed in the table below.

Table 3 : Cisco IOS Software Release Updates

Major/ED Release

Maintenance Release

Availability (CCO)



June 2, 1998

*111.1(19)C1 has integrated the software fixes listed below:

To follow the bug ID link below and see detailed bug information, you must be a registered user and you must be logged in.

Cisco Bug ID CSCdj95348 (registered customers only) - STUN basic doesnt pass data when direct is configured

Cisco Bug ID CSCdk10140 (registered customers only) - Deluxe-OC3: Interface stayed down during middle of autotest.

Cisco Bug ID CSCdk10114 (registered customers only) - Deluxe: predator crashed at ALIGN-1-FATAL: Corrupted.

Cisco Bug ID CSCdk10016 (registered customers only) - Deluxe: TCP throughput reduced due to rx cell throttle.

Cisco Bug ID CSCdk10961 (registered customers only) - Crash in fib_collect_traffic_stats.

Cisco Bug ID CSCdk10303 (registered customers only) - New appn subsystem objects files for 11.1(19)CC build.

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods: