This is on a IPv6-only 3750 running ADVIPSERVICESK9-M, Version 12.2(44)SE. Everything IPv6-wise is working correctly...except NTP. Say I want to add ntp.hexago.com to the ntp server, if I issue ntp server ntp.hexago.com it resolves to 206.162.147.153 which will not work in the IPv6-only lab (the only dual stack machine is the FreeBSD router box running the tunnel). So I tried this on my FreeBSD computer: ntp.hexago.com is an alias for hiphop.hexago.com. hiphop.hexago.com has address 206.162.147.153 hiphop.hexago.com has IPv6 address 2001:5c0:0:2::25 Then ntp server 2001:5c0:0:2::25 on the 3750 and this is the output: Switch(config)#ntp server 2001:5c0:0:2::25 ^ % Invalid input detected at '^' marker. So quite obviously that IOS doesn't support NTP over IPv6. FreeBSD's ntpdate and ntpd works correctly with IPv6. So how does one keep time between Cisco equipment on a IPv6-only network? Any comments?