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Glenn_32974's avatar
Glenn_32974
Icon for Nimbostratus rankNimbostratus
Jan 11, 2012

Inter-VLAN Routing on F5

Hello Guys!     I have been given the 172.31.39.0 / 24 network in order to create 4 Subnets to assign to corresponding VLANS       so right now I have :     172.31.39.0 / 26 subne...
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mikand_61525's avatar
mikand_61525
Icon for Nimbostratus rankNimbostratus
Jan 19, 2012
IMHO there is (in most cases) no need for a cisco (or whatever brand you like ;-) router if you already have a viprion 2x00/4x00 in your datacenter. Specially if your trafficflows are so that 99% or so of them will pass the F5 anyway. The VS used for routing (forwarding ip) wont do any SNAT on the traffic, it will just shuffle the packets (that is packets that doesnt match any other better matching VS). Also when the F5 sits inline the need for SNAT will in many cases go away aswell (compared to when it sits on a stick).

 

 

Compare the following flows as example:

 

 

client -> switch -> F5 -> firewall -> server

 

 

vs

 

 

client -> switch -> ciscorouter -> F5 -> ciscorouter -> firewall -> server

 

 

and it can be even worse if the netadmin didnt think at all like:

 

 

client -> switch -> ciscorouter -> switch -> F5 -> switch -> ciscorouter -> firewall -> server

 

 

and so on ;-)