https://community.cisco.com/t5/application-networking/waas-between-ios-15-4-3-s6a-and-ios-16-6-x/m-p/4299523#M51263 <P>I have WASS now running between my 4431 on 16.6.X and 4351 with no issue.</P><P>Another division of the company has a 4431 running 15.4(3)S6a,</P><P>&nbsp;</P><P>Is it possible to make a connection this 4431 running 15.4.x code?&nbsp; Upgrade of the 15.4 code to 16.6.x isn't an option at this point.&nbsp;</P><P>&nbsp;</P><P>my WAAS mgr is running 6.4.x code.&nbsp;</P><P>&nbsp;</P> Mon, 01 Mar 2021 19:24:03 GMT dmooreami 2021-03-01T19:24:03Z https://community.cisco.com/t5/application-networking/waas-between-ios-15-4-3-s6a-and-ios-16-6-x/m-p/4299523#M51263 <P>I have WASS now running between my 4431 on 16.6.X and 4351 with no issue.</P><P>Another division of the company has a 4431 running 15.4(3)S6a,</P><P>&nbsp;</P><P>Is it possible to make a connection this 4431 running 15.4.x code?&nbsp; Upgrade of the 15.4 code to 16.6.x isn't an option at this point.&nbsp;</P><P>&nbsp;</P><P>my WAAS mgr is running 6.4.x code.&nbsp;</P><P>&nbsp;</P> Mon, 01 Mar 2021 19:24:03 GMT https://community.cisco.com/t5/application-networking/waas-between-ios-15-4-3-s6a-and-ios-16-6-x/m-p/4299523#M51263 dmooreami 2021-03-01T19:24:03Z