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jbhpe_254247's avatar
jbhpe_254247
Icon for Nimbostratus rankNimbostratus
Mar 14, 2016

Slow browsing issue on internet and intranet sites using the F5 VIP but on F5 backend is ok

Hi,   We have some users who is using the F5 VIP (FQDN) configured on their browsers as their proxy server but having slow connection when they access the internet and intranet sites. But when t...
application delivery
LTM
Gus_135027's avatar
Gus_135027
Icon for Cirrus rankCirrus
Mar 14, 2016

Hello,

 

I would:

 

  • Capture the packets using tcpdump.
  • Open the captures in Wireshark. Try using Wireshark's Expert Info feature 'Analyse >> Expert Information'
  • Check for any protocol anomalies: check for TCP windows size, fragmentation, tcp offload settings, etc.
  • Create custom profiles for this service, so you don't disturb other VS.
  • Try tuning the tcp and/or the http profiles.
  • Check the routing between the clients and the F5 VS. And from the F5 to the nodes.
  • You might get stuck, so worth opening a ticket with F5 and include all your investigation work.
Gus_135027's avatar
Gus_135027
Icon for Cirrus rankCirrus
Mar 19, 2016
Sorry for delay... I've been away..

 

You can start with the following tcpdump command:

 

tcpdump -s0 -nni 0.0:nnnp -w /var/tmp/pcap/[filename] host [the virtual server ip] and port [the proxy port e.g. 8080]

 

E.g.:

 

tcpdump -s0 -nni 0.0:nnnp -w /var/tmp/pcap/19032016_1120_tcp.pcap host 192.168.1.200 and port 8080

 

Use a SFTP client like Filezilla to download the capture so you can open it in Wireshark, the capture will be in /var/tmp/pcap/