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Militza's avatar
Militza
Icon for Nimbostratus rankNimbostratus
Jun 28, 2023

Unable to download 15 MB excel file through LTM.

We have configured HTTP application with port 80 on F5 LTM. We trying to download excel file using that application downloading gets failed after few minutes. No logs found in var/ltm realated to do...
application delivery
  • Mohamed_Ahmed_Kansoh's avatar
    Mohamed_Ahmed_Kansoh
    Jun 28, 2023

    Hi Militza , 

    Do you see in Packet captures >>> ( TCP Window Full & TCP zero window ) while downloading this file ? 

    >Btw , Try to remove the HTTP Profile and use ( Performance layer 4 ) and Test. 

    >Are there any firewalls between F5 Bigip and Servers or between F5 Bigip and Client ).

    > Maybe adjusting window scalling solve your issue , but first tell us if you see ( TCP Window Full & TCP zero window ) flags or not in your captures ? 

Mohamed_Salah_'s avatar
Mohamed_Salah_
Icon for MVP rankMVP
Jun 28, 2023

Hello,

Can you please provide any additional information? for example: virtual server configuration (virtual server type and profiles assigned) also, is the service working fine and only downloading files is failing?

what is the software version you are running? you can check for any BUG that you might be facing, for example:

https://cdn.f5.com/product/bugtracker/ID966785.html

Also, you can start generating a tcpdump and check the output, it will be clear as the service port is 80, you can use the below command to check out what is actually happennig on both client and  server side.

#tcpdump -nnnveti 0.0:nnnp host 51.39.227.242 and port 80 -s0 -S -w /var/log/filename.pcap

replace the above IP with the client's IP, then open it in wireshark.

Thanks,