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Community Member


%C4K_HWPORTMAN-4-BLOCKEDTXQUEUE: Blocked transmit queue HwTxQId0 on Switch Phyport Gi10/46, count=13773

Does anyone know how to solve this? Other than hw-module reset or power cycle?

There must be a more elegant solution in the world of Cisco surely?



From Cisco's Output interpreter:

Configure both sides of the link to autonegotiate for speed and duplex. Issue the shut/no shut command to recover the port. If the problem persists, move the connected device to another port and see if the problem happens there. If neither of these solves the problem, issue the hw-module reset command in order to reboot the switch and reset the line card. You could also upgrade the the Cisco IOS version to the 12.2(25)EWA2 or 12.2(25)SG releases.

You can find more info here:

Community Member


Please someone must know a way to retrieve a port in this state without hw-module reset?

As we are a 24/7 company and this is just not feasible.




Sometimes you have to reset and there should be a window when you can do things like this. If not then policy and how things are setup should be looked at . A router is a computer and things do get hung up occasionally.

Community Member


Okay thanks.

From further reading it does seem to be the only option.

Its just strange that something like this can't be resolved any other way.

Thanks anyway.


Sir, since you have 24/7 support, get in touch with TAC to get the appropriate support -

This is an open forum where people volunteer and try to help each other. This is not a support group.

If you don't have a direct support with Cisco try getting in touch with your partner from whom you have purchased the devices.

-> Sushil

Community Member


Check what you have connected on that port, could we verify if that device is working properly, maybe the device connected is sending bad packets.

Furthermore, could you let me know the IOS version that your device is running.

Community Member


IOS 12.2 (40).

The device pushed out 1gig of netbios traffic in the space of a few seconds and since then the tx-queue has been blocked.

There is no device currently connected but the port is still blocked. Shut/no shut does not resolve.



Hi Michael,

Did a quick search in Bug tool Kit and here's what I found -

CSCse29295 Bug Details

Packet drop beyond > 6656 bytes and BLOCKEDTXQUEUE messages on console


On Catalyst 4948, 4948-10GE, 4013+TS supervisor and 4306-GB-T linecard, running 12.2(25)EWA6 IOS software image the following problems may be seen. These problems can occur on RJ45 ports only.

1. When sending packets of size > 6656, ports cannot sustain line-rate traffic when operating at

1Gbps. However, they can sustain line-rate traffic when packet are less than or equal to 6656 bytes when operating at 1Gbps.

2. In rare situations, the TxQueues associated with the RJ45 ports may get stuck when the packets greater than 6656 bytes are being switched, and the port is operating at either 10Mbps, 100Mbps,

or 1Gbps. Messages similar to the following may be seen on the console:

Aug 1 04:46:01 CDT: %C4K_HWPORTMAN-4-BLOCKEDTXQUEUE: Blocked transmit queue HwTxQId1 on Switch Phyport Gi1/35, count=1784

Aug 1 04:46:12 CDT: Current Freelist count 5629. Fell below threshold 601 times consecutively

Aug 1 04:46:42 CDT: Current Freelist count 5629. Fell below threshold 1202 times consecutively


These problems are only seen when running 12.2(25)EWA6.


Upgrade to 12.2(25)EWA8, 12.2(31)SGA, or 12.2(37)SG.

Although it clearly states that the effected release is 12.2(25)EWA6, but not really sure if you are hit by this bug.

Do you see any other message apart from this?

-> Sushil

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