[c-nsp] IPv6 assignment via PPTP Server

[Aftab Siddiqui]

Dear NSP,
I've configured a PPTP/VPN server (config below) to assign IPv4 and IPv6
both via local pool. Everything works fine if the client OS is either
windows7 or linux (ubuntu). But IPv6 part doesn't work for iOS 6 devices
(iPhone/iPad) and Android ICS/JB (S3, SonyXperia). It could be handheld OS
issue, but just in case if I'm missing any tweak. So any suggestion what
might be causing the problem? Google suggest that people faced the same
problem an year ago and didn't report any solution.

Router: 1841
IOS: 12.4(3f)
Config:

vpdn enable
!
vpdn-group 1
 accept-dialin
  protocol pptp
  virtual-template 1
!
interface Loopback100
 description *** Testing PPTP VPN Inf ***
 ip address 203.xyz.xyz.129 255.255.255.248
 ipv6 address 2001:1234:111::1/64
!
interface Virtual-Template1
 ip unnumbered Loopback100
 ipv6 unnumbered Loopback100
 ipv6 enable
 ipv6 nd reachable-time 30
 no ipv6 nd suppress-ra
 ipv6 virtual-reassembly
 peer default ip address pool pptp-v4
 peer default ipv6 pool pptp-v6
 no keepalive
 ppp encrypt mppe 128
 ppp authentication ms-chap ms-chap-v2
!
ip local pool pptp-v4 203.xyz.xyz.130 203.xyz.xyz.135
ipv6 local pool pptp-v6 2001:1234:110::/62 64

Regards,

Aftab A. Siddiqui