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keith_varga_107's avatar
keith_varga_107
Icon for Nimbostratus rankNimbostratus
Nov 16, 2015

ping return time <1ms but only on load balanced nodes

Hi Dev Central Team, We're running 11.6 Hotfix 3 on a active/standby physical F5 pair. We noticed that when we ping www.google.com (or any outside domain), that the time returned is less than 1 m...
BIG-IP
cloud
LTM
Brad_Parker_139's avatar
Brad_Parker_139
Icon for Nacreous rankNacreous
Nov 16, 2015

Remember, BigIP is a full proxy. When you connect to an IP that is a listener, the BigIP responds. It doesn't just pass the packet through like a switch or router. This includes a ForwardingIP virtual server that you probably have configured(0.0.0.0/0) in order to use the BigIP as your default gateway. So, the public IPs you are pinging are being responded to by the BigIP because it is on your LAN.

 

Brad_Parker_139's avatar
Brad_Parker_139
Icon for Nacreous rankNacreous
Nov 16, 2015
The TTLs are different for this very reason. 255 means that ICMP packet had no hops to be returned. 55, on the other hand, for your other servers means that returned packet took the 200 hops to be returned from google which is to be expected when the ping actually traverses all the layer 3 devices between it and your server.