dslreports logo
site
 
    All Forums Hot Topics Gallery
spc

spacer




how-to block ads


Search Topic:
uniqs
9
share rss forum feed

dabomb4097

join:2012-12-13
Willowbrook, IL
reply to koitsu

Re: [IPv6] Comcast IPv6 Gives Address But No Default Gateway

said by koitsu:

Also, the fact that you've edited your screenshots heavily, as well as cropped out useful information, does not help the situation. Please do not do this. I cannot stress this enough, especially with IPv6. For example it would really help to know if you're getting both the /64 route announcement as well as the /128, but you've hidden all the information that's needed and for no good reason.

There is no additional information on any of the pages pertaining to the IPv6 connection. Just that single enable/disable button and the status information shown. I'm running the latest firmware available from Linksys/Cisco.

Where do you think I might find this route announcement data? I've been through every page and tab, those two snippets are the only IPv6 information this particular router allows you to set or read.


koitsu
Premium,MVM
join:2002-07-16
Mountain View, CA
kudos:23

said by dabomb4097:

There is no additional information on any of the pages pertaining to the IPv6 connection. Just that single enable/disable button and the status information shown. I'm running the latest firmware available from Linksys/Cisco.

I will gladly admit I don't know enough about the E3200's native firmware to know if it will show you both the advertised /64 and the individual /128 announced by Comcast. Some routers show this, others do not. Here's an example of one which does:

»forums.comcast.com/t5/image/serv···-1&px=-1

said by dabomb4097:

Where do you think I might find this route announcement data? I've been through every page and tab, those two snippets are the only IPv6 information this particular router allows you to set or read.

It's not something that's shown (in any firmware) in the GUI. It's handled purely by the kernel/firmware when it receives it across the wire. Even on third-party firmwares like TomatoUSB this information isn't available in the GUI or via any other means (on TomatoUSB you simply have to use tools like tcpdump on the router itself, watching for ICMPv6 traffic, then decode the results yourself, or write the capture to a file and then open the file in Wireshark). So basically what I'm saying is: there is no way for you to determine if you're actually seeing RAs or not. You just have to cross your fingers and hope.
--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.

dabomb4097

join:2012-12-13
Willowbrook, IL

said by koitsu:

I will gladly admit I don't know enough about the E3200's native firmware to know if it will show you both the advertised /64 and the individual /128 announced by Comcast. Some routers show this, others do not. Here's an example of one which does:

»forums.comcast.com/t5/image/serv···-1&px=-1

Oh ok, yeah now that you mention it on the Local Network page it says the following:

Prefix Address: 2601:d:3000:44::/64

Does that offer any additional insight?

dabomb4097

join:2012-12-13
Willowbrook, IL
reply to koitsu

said by koitsu:

I will gladly admit I don't know enough about the E3200's native firmware to know if it will show you both the advertised /64 and the individual /128 announced by Comcast. Some routers show this, others do not. Here's an example of one which does:

»forums.comcast.com/t5/image/serv···-1&px=-1

Ah okay, on the Local Network tab it shows:
Prefix Address: 2601:d:3000:44::/64

Does that offer any additional insight?


koitsu
Premium,MVM
join:2002-07-16
Mountain View, CA
kudos:23
reply to dabomb4097

That means you're at least picking up the /64 prefix delegation that Comcast hands you (which is the IPv6 network block that should be used by systems on your LAN for direct IPv6 connectivity), so that means at least some RAs are working.

I have no explanation for why there's no default IPv6 gateway other than a network misconfiguration on Comcast's side or a firmware/router bug in the E3200. An alternate possibility is that Cisco DPC3000 is incorrectly filtering or messing with some kinds of IPv6 packets (strange but possible), even though cable modems aren't supposed to screw with layer 3 traffic passed through to the underlying LAN port. That's about all I can do with the information here -- IP network technicians have to figure out the rest. I'd wait for NetDog See Profile at this point.
--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.