I*t is a timing issue.* I just forwarded the Access Request to another radius server (Domain Controller) which replies immediately - access accepted, VPN client logged in successfully. If I put a 'sleep 10' in the shell script (duo2.sh) before the radtest (please see below) to send the request to the Domain Controller (10.101.168.3), then the VPN connection fails like with the DUO.
Does the NAS have a timing limit on establishing a tunnel? If that's the case, I suggest you look at increasing that limit to allow a DUO 2FA to happen. Stefan Paetow Moonshot Industry & Research Liaison Coordinator t: +44 (0)1235 822 125 gpg: 0x3FCE5142 xmpp: stefanp@jabber.dev.ja.net skype: stefan.paetow.janet jisc.ac.uk Jisc is a registered charity (number 1149740) and a company limited by guarantee which is registered in England under Company No. 5747339, VAT No. GB 197 0632 86. Jisc’s registered office is: One Castlepark, Tower Hill, Bristol, BS2 0JA. T 0203 697 5800.