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Large sequence numbers on FWSM

We recently installed a 6509 with FWSM and noticing pretty large sequence numbers like this:

" %FWSM-6-302016: Teardown UDP connection 144551535502653717"

Is that normal?

1 ACCEPTED SOLUTION

Accepted Solutions
Cisco Employee

Re: Large sequence numbers on FWSM

Yes. Either a reload or after its hits the maximum decimal integer made up of these 8 bytes(64 bits), I believe 20 digits is hit it will reset back to the smaller number. So according to all 1s 64 digits the max decimal number is

18446744073709551615 (20 digits).

I used this site to convert binary to decimal:

http://www.exploringbinary.com/binary-converter/

-Kureli

10 REPLIES
Cisco Employee

Large sequence numbers on FWSM

Mohammad,

That may not be the seq. nos used by the end hosts in the connection. It is just a connection ID that the FWSM uses to identify that particular UDP connection. It is sequentially assigned. It is an 8 byte integer made out of xlate ID and sequence counter (4 bytes each).  How long has the unit been up? Did you all increase the xlate timeout from the default 3 hours?

-Kureli

Large sequence numbers on FWSM

Thank you for the reply sorry about the wording yes it is the connection ID not the sequence number I said it wrong.  Xlate is still default of 3 hours and unit has been up since september 2011.

So the connection ID's that long are normal on FWSM?

Cisco Employee

Large sequence numbers on FWSM

Yes it is normal. Although this one is a a lot longer than the ones that I see usually .

-Kureli

Large sequence numbers on FWSM

Thank you again so should this be a concern?

Cisco Employee

Large sequence numbers on FWSM

No. Don't worry about it. Get me the

sh xlate count

sh conn count

output from the FWSM.

-Kureli

Large sequence numbers on FWSM

# show xlate count

355 in use, 1310 most used

# show conn count

215 in use, 365939 most used

Thank you again here is the output.

Cisco Employee

Large sequence numbers on FWSM

Interesting. So at some point the blade has seen 365939 connections when at present there are only 215.

So, that explains the very high sequential connection ID increase.

-Kureli

Large sequence numbers on FWSM

Ok so once the xlate times out shouldn't the connection ID's get smaller ?  or will the device reboot can only accomplish that?

Cisco Employee

Re: Large sequence numbers on FWSM

Yes. Either a reload or after its hits the maximum decimal integer made up of these 8 bytes(64 bits), I believe 20 digits is hit it will reset back to the smaller number. So according to all 1s 64 digits the max decimal number is

18446744073709551615 (20 digits).

I used this site to convert binary to decimal:

http://www.exploringbinary.com/binary-converter/

-Kureli

Large sequence numbers on FWSM

Thankk you so much for all your help and explaining everything have a great day.

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