Is Xtra filtering proto 41 (IPv6) which is used by 6to4 tunnels?

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Jamey

4 posts

Wannabe Geek

Topic # 112958 29-Dec-2012 14:12

Has anyone had any success setting up 6to4 from a home Xtra broadband connection?

I've been playing around with Linux & Mac boxes (behind NAT) and a Cisco router (which is assigned the public IPv4 addr) and a dual-stacked (telehoused outside Xtra's nw) Linux box but all my testing seems to suggest that Xtra are filtering protocol 41 - even though my traceroute attempts with raw GRE also fail but which I know to work because of the functioning VPN using it.

I can ping 192.88.99.1 (and traceroutes appear to go to .au...) from home (...traceroute from my colo'd box reaches fx.net.nz in Wgtn) and I've even tried using my colo'd box as a relay but the IPv4 traffic doesn't seem to make it there.

The one thing that would give me certainty which I can't do is put a Linux box in the place of the Cisco router to see if any proto 41 traffic makes to the the public IPv4 address but then if they are filtering this outbound traffic then it's unlikely inbound would get through.

Any ideas/knowledge on this subject please?

Zeon

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Reply # 738329 29-Dec-2012 14:35

Try to connect your computer directly onto the public IPv4 address (ie maybe get a bridging modem and connect the PPP session from your computer). I suspect one of your devices is filtering it out - GRE doesn't do well with NAT.

hashbrown

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Reply # 738346 29-Dec-2012 15:08

I have a working 6to4 setup on Xtra, so it does work. An ACL on the Cisco will tell you if you are getting packets.

Does the Cisco support ipv6? That might be an easier way to go.

plambrechtsen

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Reply # 738523 30-Dec-2012 10:41

I can say uncategorically that Telecom doesn't filter any traffic apart from TCP port 25 (SMTP) to stop computers infected with viruses sending bulkloads of spam. You can opt out of that filter by contacting the broadband helpdesk.

So I suspect it's something wrong with your configuration... And as others said can't you configure the 6to4 tunnel on your router? As long as you have new enough IOS then you should be away. I configured a 6to4 on a old Cisco 1721... Just needed enough ram and new enough IOS.

Jamey

4 posts

Wannabe Geek

Reply # 738824 31-Dec-2012 11:01

Thanks guys (why doesn't this site email me to say someone replied like fb does?! - I only read your replies because I came here to post an update.)

I managed to get it going (sometimes it pays to sleep on a problem huh), some weirdness with using traceroute -P 41 going on I suspect, _and_ some weirdness pinging/tracerouting from the Cisco itself (an 877 w/ current 12.4/15.x so yes it supports IPv6 & 6to4, duh) - ping & traceroute are only working to/from the inside nw, I cannot use any of the router's 6to4 addresses as an endpoint to ping from outside.

It's also working flawlessly with my GRE multipoint VPN (I was concerned that I'd have to drop this to make 6to4 work due to a comment in some Cisco docs).
(I don't know why someone suggested GRE has issues with NAT, I can PPTP through it just fine, unless your foreign endpoint is handing out addresses in the same range as your internal subnet - that's not good, tried changing your internal nw range?).

Very pleased, just a shame my nearest relay is in Aussie.

Zeon

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Reply # 738827 31-Dec-2012 11:11

When will Telecom be offering native IPv6?

RunningMan

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Reply # 738853 31-Dec-2012 13:12

Jamey: Thanks guys (why doesn't this site email me to say someone replied like fb does?! - I only read your replies because I came here to post an update.)

It does if you want it to. This can be configured globally in your profile, for just one topic, there is a check box right next to the "Post Reply" button.