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Gestione_Reti_W's avatar
Gestione_Reti_W
Icon for Nimbostratus rankNimbostratus
Aug 10, 2018
Solved

F5 LTM - SNAT fails in a /23 subnet

Hello all. We have installed a couple of BIG-IP LTM 1600 v11.3.0 (Build 3138.0) in active-passive mode. This cluster balances servers in two different DMZ (using Route Domains). Now the business aske...
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  • Dan_Pacheco_163's avatar
    Dan_Pacheco_163
    Aug 10, 2018

    This behavior is strange. When I create a snatpool I typically select a snat subnet that is not shared with the servers. The behavior you are describing makes it sound like your cisco router has two /24 interfaces instead of a single /23. I assume this has been checked?

     

Dan_Pacheco_163's avatar
Dan_Pacheco_163
Icon for Cirrus rankCirrus
Aug 10, 2018

This behavior is strange. When I create a snatpool I typically select a snat subnet that is not shared with the servers. The behavior you are describing makes it sound like your cisco router has two /24 interfaces instead of a single /23. I assume this has been checked?

 

  • Gestione_Reti_1's avatar
    Gestione_Reti_1
    Icon for Nimbostratus rankNimbostratus
    Aug 20, 2018

    Hello Dan, tahnks for your answer and sorry for the late of mine. I didn't really considered your suggestion, but is a good idea. I just tried with a test Virtual Server using a "172.16.16.x/24" SNAT POOL subnet and it seems to work. I'll deeply test this at next configuration request. (anyway the Cisco router configuration is ok...)

     

    Thanks again Dan.

     

    Have anice day.

     

    Stefano.