intended xfrm replay-window is not getting configured on kernel 4.9
 

i am trying to configure replay-window 512 on kernel 4.9 for ipsec configuration , but still xfrm is configuring it as 0 . can some body help on this do we have any open BUG in the xfrm code on 4.9 linux kernel.
appreciate your comments on this
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config:
ip xfrm state add src 3.1.1.33 dst 101.0.33.1 proto ah spi 0x210 reqid 2 mode tunnel replay-window 64 auth-trunc sha1 0x12345678bef217722ada4f77397bb90c08b62c01 96
ip xfrm state add src 101.0.33.1 dst 3.1.1.33 proto ah spi 0x310 reqid 1 mode tunnel replay-window 64 auth-trunc sha1 0x123456783f3c0a126429009b16e4abdcec2c8e7b 96

=================
src 101.0.33.1 dst 3.1.1.33
proto ah spi 0x00000310 reqid 1 mode tunnel
replay-window 0
auth-trunc hmac(sha1) 0x123456783f3c0a126429009b16e4abdcec2c8e7b 96
anti-replay esn context:
seq-hi 0x0, seq 0x0, oseq-hi 0x0, oseq 0x0
replay_window 64, bitmap-length 2
00000000 00000000
sel src 0.0.0.0/0 dst 0.0.0.0/0
src 3.1.1.33 dst 101.0.33.1
proto ah spi 0x00000210 reqid 2 mode tunnel
replay-window 0
auth-trunc hmac(sha1) 0x12345678bef217722ada4f77397bb90c08b62c01 96
anti-replay esn context:
seq-hi 0x0, seq 0x0, oseq-hi 0x0, oseq 0x0
replay_window 64, bitmap-length 2
00000000 00000000
sel src 0.0.0.0/0 dst 0.0.0.0/0