hello
I have a mikrotik routerboard (1100AHx2 firmware: 3.22 )
I know this is an old version.but for some reasons I can’t upgrade it.
I want to know , does it support NAT-T ???
for l2tp-ipsec behind nat .
cause after configuration clients behind a nat can’t connect to my l2tp-ipsec .
Oldest I can quickly find is 3.30 and it does have NAT Traversal checkbox, so I guess 3.22 could have it too. And if it’s there, it probably does something.
What I don’t understand is why or even how you’d have RouterOS from 2009 on device released in 2011, that sounds suspicious.
welcome to my club 
I don’t know too!!! this is for ex admin.
actually my router has nat traversal option but it doesn’t work correctly.
you know, when my client try to connect wihout nat everything is goint to be fine, but clients behind the nat won’t.
is it possible there is “nat traversal option” there, but it doesn’t work?
Possible, maybe. You can try to find old changelogs and see if there’s any such fix mentioned in following versions. But there’s no guarantee it would be there, because old changelogs were very brief. Or you can download old x86 3.22 (it was extremely popular version, I’m sure you’d still find it today 
) and make a virtual testing lab. But it wouldn’t really help you much, regardless if it would work or not.
I’m sure you know what’s the right answer, RB1100AHx2 is still supported and it can be upgraded to latest version which has tons of IPSec updates compared to yours, so …
sure…
thank you very much indeed