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WeaverJK's avatar
WeaverJK
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May 05, 2016

Troubleshootig LTM issues

Hi all. I'm new to load balancers and F5. In preparation for arrival of F5 hardware, I've been working with F5 evaluation licenses (usually, the 45-day licenses provided by F5 Sales staff).   No...
application delivery
LTM
neptune_121018's avatar
neptune_121018
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May 05, 2016

Have you enabled Source Address Translation: Automap on the Virtual Server? (It may show as SNAT in some versions).

You can also check the Virtual Server and Pool statistics to see if traffic is going in and out. You can find those on:

Local Traffic > Virtual Servers > Statistics

Local Traffic > Pools > Statistics

You can also run a tcpdump from the bash command line, for example:

tcpdump -nni 0.0

which will show you the traffic that's going through the traffic interfaces.

Other examples:

tcpdump -nni vlan_name

tcpdump -nni 0.0 host 192.168.x.x

You can see more examples in SOL411

neptune_121018's avatar
neptune_121018
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May 09, 2016
Source Address Translation Automap is used when the pool members don't have their default gateway or a route pointing to an F5 Self IP... When Automap is enabled the server side part of the connection originates from the F5 Self IP that's on the pool member's VLAN, this makes the pool member's response to be directed to the F5 Self IP, causing both request and response to go through the F5, a requirement of the full-proxy architecture. Check figure 15.1 on this link for a graphical explanation: https://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/ltm_configuration_guide_10_1/ltm_snat.html1213504