dslreports logo
site
 
    All Forums Hot Topics Gallery
spc

spacer




how-to block ads


Search Topic:
uniqs
15
share rss forum feed


NathanO

join:2008-08-21
Moorestown, NJ
reply to koitsu

Re: TomatoUSB and Comcast IPv6 -- bugs found

TomatoUSB If you don't mind.


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

2 edits

1 recommendation

root@gw:/tmp/home/root# ifconfig
br0        Link encap:Ethernet  HWaddr E0:CB:4E:C0:00:C4
           inet addr:192.168.1.1  Bcast:192.168.1.255  Mask:255.255.255.0
           inet6 addr: 2601:9:4600:4f:e2cb:4eff:fec0:c4/64 Scope:Global
           inet6 addr: fe80::e2cb:4eff:fec0:c4/64 Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:45925 errors:0 dropped:0 overruns:0 frame:0
           TX packets:47375 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:3860081 (3.6 MiB)  TX bytes:11130952 (10.6 MiB)
 
eth0       Link encap:Ethernet  HWaddr E0:CB:4E:C0:00:C4
           inet6 addr: fe80::e2cb:4eff:fec0:c4/64 Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:181168 errors:0 dropped:0 overruns:0 frame:0
           TX packets:92179 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:1000
           RX bytes:21808810 (20.7 MiB)  TX bytes:15741818 (15.0 MiB)
           Interrupt:4 Base address:0x2000
 
eth1       Link encap:Ethernet  HWaddr E0:CB:4E:C0:00:C6
           inet6 addr: fe80::e2cb:4eff:fec0:c6/64 Scope:Link
           UP BROADCAST RUNNING ALLMULTI MULTICAST  MTU:1500  Metric:1
           RX packets:15 errors:0 dropped:0 overruns:0 frame:438284
           TX packets:640 errors:9 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:1000
           RX bytes:2846 (2.7 KiB)  TX bytes:272035 (265.6 KiB)
           Interrupt:3 Base address:0x1000
 
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 MULTICAST  MTU:16436  Metric:1
           RX packets:10 errors:0 dropped:0 overruns:0 frame:0
           TX packets:10 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:1330 (1.2 KiB)  TX bytes:1330 (1.2 KiB)
 
vlan1      Link encap:Ethernet  HWaddr E0:CB:4E:C0:00:C4
           inet6 addr: fe80::e2cb:4eff:fec0:c4/64 Scope:Link
           UP BROADCAST RUNNING ALLMULTI MULTICAST  MTU:1500  Metric:1
           RX packets:45918 errors:0 dropped:0 overruns:0 frame:0
           TX packets:47392 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:4043263 (3.8 MiB)  TX bytes:11323312 (10.7 MiB)
 
vlan2      Link encap:Ethernet  HWaddr E0:CB:4E:C0:00:C5
           inet addr:67.180.84.87  Bcast:67.180.87.255  Mask:255.255.252.0
           inet6 addr: fe80::e2cb:4eff:fec0:c5/64 Scope:Link
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:135247 errors:0 dropped:0 overruns:0 frame:0
           TX packets:44781 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:14504373 (13.8 MiB)  TX bytes:4417878 (4.2 MiB)
 

Important bits:

1. Comcast via DHCPv6 delegates to me 2601:9:4600:4f::/64. This will certainly vary per person.

2. My br0 interface (WiFi+LAN) has the IPv6 address 2601:9:4600:4f:e2cb:4eff:fec0:c4. This is part of the delegation from Comcast (hard to explain; the last 64 bits are a combination of the interface MAC address -- rather not get into it).

3. Be sure when reading the IPv6 addresses that you take note of the Scope:Global and Scope:Link specifiers. Global what comes from Comcast (effectively), and Link is the local-link address (self-generated).

And just to add further clarification: my FreeBSD box has IPv6 address 2601:9:4600:4f:230:48ff:fed2:22d0 (prefix length 64 too), and as you can see, that also falls within 2601:9:4600:4f::/64 which is delegated by Comcast.

It's actually classic/simple subnetting, just with two octets (16 bits) per section (0-65535, or 0 to ffff) and a colon delimiter, rather than a single octet (8 bits per section, or 0-255) and a dot/period delimiter like IPv4.
--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.