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New Member

Keepalives and ack´s lost in a Serial Link (HDLC)

Hi everybody,

Does someone know whether is normal to lose once in a while the acknowledges of myseq and the remote keepalives (yourseen)???, check the debug messages at 09:20:57 and 09:21:07 and you will see what I am talking about.

Any comments will be apreciated.

Thanks in advance.

Feb 7 09:20:37: Serial5/0/0: HDLC myseq 24175, mineseen 24175*, yourseen 24198, line up

Feb 7 09:20:47: Serial5/0/0: HDLC myseq 24176, mineseen 24176*, yourseen 24199, line up

Feb 7 09:20:57: Serial5/0/0: HDLC myseq 24177, mineseen 24177*, yourseen 24201, line up

Feb 7 09:21:07: Serial5/0/0: HDLC myseq 24178, mineseen 24177, yourseen 24201, line up

Feb 7 09:21:17: Serial5/0/0: HDLC myseq 24179, mineseen 24179*, yourseen 24202, line up

Feb 7 09:21:27: Serial5/0/0: HDLC myseq 24180, mineseen 24180*, yourseen 24203, line up


Cisco Employee

Re: Keepalives and ack´s lost in a Serial Link (HDLC)

If your upper-layer protocol traffic is getting through reliably and your wan link is clean, then you'll want to check the interfaces and the CPU load (remote end). If the CPU load is high on the other end, the keepalives could get dropped, as they are process switched. Also low memory could produce the same result. Throttles and drops on the interfaces involved are indications of high CPU and low memory issues. Issuing the command "show proc cpu" during times when keepalives are unacknowledged will give you an idea as to whether the CPU load is an issue. "show interface" will show your throttles and your input/output drops. You might find the URL below helpful...