NAT issue,do not understand

Hi!
My Asterisk(11.11) PBX have 2 interfaces:
1 - eth1 LAN interface, with NATted access to Internet
2 - eth0 interface to SIP providers lan with 172.xxx.xxx.xxx IP, without nat

in sip.conf directly defined an externip and
that connect to sip provider is noNAT (nat=no)

all routes are correct
But…somehow Asterisk send externip in sip messages adressed to noNATed SIP-providers peer!

any suggestions?
Thanks!

I think I resolve problem…
Was must to add 2-nd string of localnet=xxx.xxx.xxx.xxx type , where xxx.xxx.xxx.xxx - providers network :blush: