7 ms·

Comcast releases 'AFTR': Open Source IPv4 to IPv6 Routing

19 points by bacarter 16y ago

cscotta 16y ago
This is really cool to see. IPv6 is the internet's "peak oil" problem, or a "long emergency" - most seem to think of the transition as a "maybe someday" nice to have, without realizing how few blocks remain in the IPv4 address space. It's refreshing to see a major ISP take the initiative to prepare their networks, but also release software to help others route between IPv4 and IPv6 networks. Speaking of which, you can download it here: https://www.isc.org/software/aftr https://www.isc.org/software/aftr That said...I'd prefer that most of the source weren't a 13,217-line file with rare, cryptic comments called "aftr.c" ;-). PDF'd manpages: http://u.phoreo.com/rh.pdf http://u.phoreo.com/rh.pdf
- mprovost 16y ago
  IPv6 is more like "solar power" in your analogy. We're going to run out of oil/IPv4 someday and have to replace it with something, but not necessarily IPv6. Actually IPv6 is probably more like "atomic fusion" - some utopian grand project that will fix everything but nobody quite knows how we're going to get it to work.
  - wmf 16y ago
    The idea that IPv4 will be replaced with something that isn't IPv6 is no longer credible. We need a solution in 2012, and nothing else is going to be ready by that time.
    - mprovost 16y ago
      Well it wouldn't take much for something else to outpace the adoption rate of IPv6. I think something will come along that is backwards compatible with v4. We're already seeing things like carrier grade NAT that are just bandaids but we can live with bandaids for a long time...
    - prodigal_erik 16y ago
      After this long, I'm starting to think we're actually more likely to see cataclysmic earthquakes and flooding in 2012 than adoption of IPv6.
hvs 16y ago
Good for them. I have very few kind words for Comcast, RCN, AT&T, and their ilk, but I have to say that this was a surprisingly forward-thinking decision on their part.
- jf 16y ago
  The only reason I'm still a Comcast customer is because I want to be in their IPv6 beta trials.
  - FlorinAndrei 16y ago
    The only reason I'm still a Comcast customer is because there's no other broadband alternative in my area. No, 128 kbps is not broadband. So, I'm stuck.
maukdaddy 16y ago
static char addrbuf[8][NI_MAXHOST]; /* XXX ugly thread-unsafe hack */ /* XXX: assume this succeeds */ inet_ntop(family, addr, cp, NI_MAXHOST);
- mustpax 16y ago
  I know we all love to hate Comcast, but you can find similar short-term hacks in any code base. 3 lines of code doesn't necessarily make the rest of released source useless.
- Kadin 16y ago
  At least they're honest about it. Calling them out because they were blunt in a comment just encourages them to be more subtle, not necessarily write better code. And particularly in an open-source project, bluntness like that is helpful since it tells other contributors what needs to be replaced ASAP.
lenni 16y ago
On a related note, can I as a consumer do anything to help IPv6 along?
- wmf 16y ago
  Not really. You could enable Teredo so that the fraction of IPv6 traffic on the Internet rises from 0.1% to 0.2%, but nobody is going to take action based on that.
- bacarter 16y ago
  Actually, you can sign up to be a Comcast IPv6 beta tester: http://www.comcast6.net/volunteer.php http://www.comcast6.net/volunteer.php
  - FlorinAndrei 16y ago
    I wonder what are the potential problems. I've a Linux system as a NAT firewall in front of everything else. It's also running an email server and a couple websites (via a dynamic IP provider). Behind it there's a couple laptops, two desktops, game consoles, iPhones, etc. I wonder what's going to stop working if I switch to IPv6 for my frontend.
dmv 16y ago
I found this relevant NANOG37 (2006) presentation pretty interesting about Comcast's IP space problem: http://www.nanog.org/meetings/nanog37/abstracts.php?pt=MzQ5Jm5hbm9nMzc=&nm=nanog37 http://www.nanog.org/meetings/nanog37/abstracts.php?pt=MzQ5J... "Managing 100+ million IP addresses"
aidenn0 16y ago
For a long time there was a resistance in the ipv6 crowd from doing something like this, due to the fact that it would make having an ipv4 only service an upside-only proposition (all ipv4 and ipv6 nodes can reach you) thus slowing down the adoption of ipv6. Since ipv6 can't possibly be adapted slower than it is now shrug

19 points by bacarter 16y ago

This is really cool to see. IPv6 is the internet's "peak oil" problem, or a "long emergency" - most seem to think of the transition as a "maybe someday" nice to have, without realizing how few blocks remain in the IPv4 address space. It's refreshing to see a major ISP take the initiative to prepare their networks, but also release software to help others route between IPv4 and IPv6 networks. Speaking of which, you can download it here: https://www.isc.org/software/aftr https://www.isc.org/software/aftr That said...I'd prefer that most of the source weren't a 13,217-line file with rare, cryptic comments called "aftr.c" ;-). PDF'd manpages: http://u.phoreo.com/rh.pdf http://u.phoreo.com/rh.pdf

mprovost 16y ago
IPv6 is more like "solar power" in your analogy. We're going to run out of oil/IPv4 someday and have to replace it with something, but not necessarily IPv6. Actually IPv6 is probably more like "atomic fusion" - some utopian grand project that will fix everything but nobody quite knows how we're going to get it to work.
- wmf 16y ago
  The idea that IPv4 will be replaced with something that isn't IPv6 is no longer credible. We need a solution in 2012, and nothing else is going to be ready by that time.
  - mprovost 16y ago
    Well it wouldn't take much for something else to outpace the adoption rate of IPv6. I think something will come along that is backwards compatible with v4. We're already seeing things like carrier grade NAT that are just bandaids but we can live with bandaids for a long time...
  - prodigal_erik 16y ago
    After this long, I'm starting to think we're actually more likely to see cataclysmic earthquakes and flooding in 2012 than adoption of IPv6.

hvs 16y ago

Good for them. I have very few kind words for Comcast, RCN, AT&T, and their ilk, but I have to say that this was a surprisingly forward-thinking decision on their part.

jf 16y ago
The only reason I'm still a Comcast customer is because I want to be in their IPv6 beta trials.
- FlorinAndrei 16y ago
  The only reason I'm still a Comcast customer is because there's no other broadband alternative in my area. No, 128 kbps is not broadband. So, I'm stuck.

maukdaddy 16y ago

static char addrbuf[8][NI_MAXHOST]; /* XXX ugly thread-unsafe hack */ /* XXX: assume this succeeds */ inet_ntop(family, addr, cp, NI_MAXHOST);

mustpax 16y ago
I know we all love to hate Comcast, but you can find similar short-term hacks in any code base. 3 lines of code doesn't necessarily make the rest of released source useless.
Kadin 16y ago
At least they're honest about it. Calling them out because they were blunt in a comment just encourages them to be more subtle, not necessarily write better code. And particularly in an open-source project, bluntness like that is helpful since it tells other contributors what needs to be replaced ASAP.

lenni 16y ago

On a related note, can I as a consumer do anything to help IPv6 along?

wmf 16y ago
Not really. You could enable Teredo so that the fraction of IPv6 traffic on the Internet rises from 0.1% to 0.2%, but nobody is going to take action based on that.
bacarter 16y ago
Actually, you can sign up to be a Comcast IPv6 beta tester: http://www.comcast6.net/volunteer.php http://www.comcast6.net/volunteer.php
- FlorinAndrei 16y ago
  I wonder what are the potential problems. I've a Linux system as a NAT firewall in front of everything else. It's also running an email server and a couple websites (via a dynamic IP provider). Behind it there's a couple laptops, two desktops, game consoles, iPhones, etc. I wonder what's going to stop working if I switch to IPv6 for my frontend.

dmv 16y ago

I found this relevant NANOG37 (2006) presentation pretty interesting about Comcast's IP space problem: http://www.nanog.org/meetings/nanog37/abstracts.php?pt=MzQ5Jm5hbm9nMzc=&nm=nanog37 http://www.nanog.org/meetings/nanog37/abstracts.php?pt=MzQ5J... "Managing 100+ million IP addresses"

aidenn0 16y ago

For a long time there was a resistance in the ipv6 crowd from doing something like this, due to the fact that it would make having an ipv4 only service an upside-only proposition (all ipv4 and ipv6 nodes can reach you) thus slowing down the adoption of ipv6. Since ipv6 can't possibly be adapted slower than it is now shrug