here is my sources.list,
apt-get update & apt-get upgrade & apt-get dist-upgrade is still 4.2.2.
pve-enterprise disabled.
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vi /etc/apt/sources.list
deb http://ftp.debian.org/debian jessie main contrib
# security updates
deb http://security.debian.org jessie/updates main contrib
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I've proxmox 4.2 versión without subscription key into production servers and i want know if it's posible to upgrade from 4.2 a 4.3 and which steps should I follow
PVE-No-Subscription is officially not for production use. The only repository that is production-ready is the enterprise repository.
The steps you should take are already discussed here on this thread multiple times, it's the pve-no-subscription repository. Please use that or buy a subscription. There are no other choices.