Adding multiple ipv6 addresses to a single interface using ioctl

Question

I am trying to port my application to ipv6 and my current code brings up alias IP addresses dynamically as shown:

eth0      Link encap:Ethernet  HWaddr 00:16:35:68:21:5B
          inet addr:192.168.1.245  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::216:35ff:fe68:215b/64 Scope:Link
          UP BROADCAST RUNNING  MTU:1500  Metric:1
          RX packets:278885750 errors:0 dropped:0 overruns:0 frame:0
          TX packets:68117973 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:68976932662 (64.2 GiB)  TX bytes:39384521280 (36.6 GiB)
          Interrupt:169

eth0:1    Link encap:Ethernet  HWaddr 00:16:35:68:21:5B
          inet addr:192.168.1.246  Bcast:192.168.1.255  Mask:255.255.255.0
          UP BROADCAST RUNNING  MTU:1500  Metric:1
          Interrupt:169

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:6060179 errors:0 dropped:0 overruns:0 frame:0
          TX packets:6060179 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:2366257047 (2.2 GiB)  TX bytes:2366257047 (2.2 GiB)

eth0:1 will be added dynamically by the application. It uses ioctl to do this. I want to do the same for IPV6 address. I tried this Assign ipv6 address using ioctl. But the example code is adding IPV6 address to the existing interface eth0 instead of eth0:1 or eth0:2 even if I specify the interface name as eth0:1. Can anyone please help since I am new to IPV6.

Answer 1

This is normal behaviour. In IPv4 each interface could have only one address. To add more addresses you had to create 'fake' interfaces like eth0:1. IPv6 always has multiple addresses per interface so work-arounds like eth0:1 are not used for IPv6.