wl 500g and ipv6

[arch]

I have recompiled 1.9.2.7-7e with every #HAVE_INET6=y changed to HAVE_INET=y. I lack the courage to upload it into my wl500gx because I am afraid that it might be too big. How can I tell?

Here are the few numbers that I have.
Modified firmware .trx file 3,510,272
Unmodified 3,506,176
Difference 4096

Modified target.cramfs 2,803,187
Unmodified 2,797,695
Difference 5492

The vmlinuz are almost the same: the new one is smaller than the old one by 86

Thanks in advance for any ideas.

[arch]

I uploaded the modified firmware, and it seems to be working. I say "seems" because I have used it for just a couple of days.

Looking at the output of dmesg immediately after reboot shows the following flash memory layout:

pmon 0 to 262,144
linux 262,144 to 4,063,232
rootfs 967,792 to 4,063,232 Note: rootfs is inside linux
config 4,063,232 to 4,128,768
nvram 4,128,768 to 4,194,304

The only change caused by the modification of the firmware was that the rootfs increased by 86 bytes. Apparently, this did not "break" anything.
Whew!

The recompilation was relatively straightforward. I followed the wiki here step-by-step. However, before I did so I had to replace the gcc and g++ on my Fedora Core 4 box with gcc and g++ 3.2. How to do this is described elsewhere on this site. From then on I had a few "path" problems where the compiler could not find something. These were caused by my hasty deviations from the wiki: do what it says. Note that the wiki DOES NOT tell you to "make uclibc"! You will be using the binary, and it is already made. As the last step I picked "make image-WL500gx", and it worked fine.

The change I made was to replace #HAVE_INET6=y by HAVE_INET6=y. At each step I took time to search, and make the change everywhere possible.

The recompilation took a long time on my 500Mhz Linux box.

And I can see that ipv6 is now enabled in ppp. More later.

[arch]

I now have a native ipv6 connection through my wl500gx router.

In the "Additional pppd options" window of IP Config-WAN&LAN in the internet interface I entered

ipv6 , ipv6cp-use-persisten

The comma and spaces are intended. If I did this before I re-compiled the firmware to enable ipv6 in ppp, the router would not signon to internet. Now it does. I could sniff the exchange of packets between the router and the ADSL modem, and I could see ipv6 being set up.

To sniff the packets I used the Tethereal ipkg package. I assume Tcpdump would work, too. The command

killall -1 pppd

disconnects, not reboots, the router and reconnects it about 30 seconds later. This gives time to start Tethereal. The command

tethereal -i vlan1

sniffs the packets going through the WAN interface. Note that rebooting will not work because Tethereal will not be running during the connection of the router.

An ipv6 global default route is not set up automatically so I added one.

ip -f inet6 route add 2000::/3 dev ppp0 metric 9999

The huge metric is to avoid packets bouncing back and forth between me and my ISP. At the moment this route is added manually after each reboot.

Normally my ISP expects me to use dhcpv6 to get my prefix, but I do not have it on the wl500gx router yet. However, I do have dhcpv6 on my Linux box, and I got the prefix using it. Apparently my ISP uses dhcpv6 just to give out prefixes and, at the moment, nothing else.

My connection to internet is now dual-stack; that is, either ipv4 or ipv6 is used as appropriate. This is not something that I did; it is built in.

My evidence that I really do have ipv6 connection capability in addition to ipv4 is that several ipv6 sites have told me that I do. Some have even sent back my ipv6 address.

The set up here is fragile, and I need to play with the system more, and I would like to have a dhcpv6 ipkg.