Airtel is rolling out IPv6 on their wired broadband services

[Chip]

@ishanjain28 I am not sure if the prefix remains constant or not, haven't experimented enough and frankly couldn't care too much as I am on a static IPv4. But the Nokia ONT has a /64 PD value which means the first 64 bits are probably constant and will work per their DHCP server configuration. I will need to check if it accepts a /60 or higher but I doubt it.

So I used the same /64 PD value on pfSense and it worked pretty well till I realised it did not assign a v6 to devices on the LAN. Obviously that requires more tinkering which I may resort to in due course with some tips from @panks21

Thanks @panks21! Can you share a screen shot or just a small post with your Airtel v6 WAN settings and that of any changes to LAN, track interface for example, and pfSense RA. I have v6 configured properly for Tata Play and those settings remain permanent. Not sure how Airtel differs.

 

[Chip]

Guys, this is the Airtel Nokia ONT IPv6 PD value (/64).

 

[doineedto]

Same here! Getting a /64 address on the Nokia ONT, but a /128 address on the bridged router. Previously used to get a /64 address on the bridged router as well.
Effectively, none of the downstream devices can use IPv6.

 

[Chip]

@doineedto I am able to get a v6 via the Nokia router on all downstream devices. Anything downstream may be assigned a /128 including your bridged router. However I need to check if its a 64 or 128.

Please recheck your v6 settings to confirm. Other downstream devices may be assigned a v6 by the Nokia provided you have switched off DHCPv6 on your personal router. At the most just keep RA on, letting the Nokia via Airtel's DHCPv6 do the work.

 

[doineedto]

@Chip forgot to mention that I am not on pfSense.
I am able to get a v6 for all the clients connected to the Nokia ONT. But we enable bridge mode just so that we don't have to use the Airtel ONT right!
I thought that the bridged device is considered a separate connection, not a downstream of the Airtel ONT. So technically it should be getting a /64 address right?

 

[Chip]

So technically it should be getting a /64 address right?

Yes that's right. The problem is I am still trying to find my way around airtel's v6 deployment. I get a /64 on Tata Play but still not sure if it is so on Airtel. Other than what I saw in the screenshot I shared I have no idea what else the PD could be

However, given the Nokia itself has a /64, those addresses can also be assigned to downstream devices, in theory, even if in bridged mode provided you have RA and DHCPv6 settings correctly set up on the personal router. Heck, with v6 there literally never will be a shortage of addresses for a very very long time to come. So I am unable to understand what the hell Indian ISPs are trying to do being so stingy. It is pathetic. Most ISPs overseas assign /48 or larger.

PS - Restarted my ONT - It is getting a /64 for sure as are downstream devices when connected to the ONT via wireless.

 

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[doineedto]

Up until the switch a few days back where Airtel pushed the new config to the ONT, my setup on the bridged router was working perfectly, with all the downstream devices getting a v6 address. Something has changed in the last few days, and my bridged router no more gets a /64 address. Now it is /128.
Perhaps we can get some help from the Airtel team. I will send them a mail soon

 

[Chip]

Trust me, Airtel's support don't know their a$$es from their elbows. When I called in Sept 21 about v6 roll out the character I spoke to was like "Huh?! What's that?" Don't expect answers from them because they only parrot the official line. Talk directly to a backend guy or one of the techs who install the modem etc they may know.

One more thing, check if your personal router's IPv6 settings to /64. Which one do you use? Not sure if it has granular control over settings.

 

[doineedto]

Lucky for me I have the contact details of the local head of the tech team. I normally get in touch with him and he directly routes me to the backend team. No hassle of talking to the L1 support who don't understand what we say!
I am using an Asus RT-AC58U with OpenWRT. Until now, I was using the auto config option which was working fine. But I will now try the manual option to tweak the settings and check if it changes anything!

 

[doineedto]

Upon manually requesting a /64 address on the bridged device, the device has been allocated one. Downstream devices now have correct IPv6 connectivity