Failing Traceroutes on kernels newer than 2.6.17
 

Hi,
In an attempt to finally upgrade to the 2.6 kernel, I installed Slack -current, but
as usual, I found that it broke my ability to visit many websites. All works well using
Slackware with a 2.4 kernel, and even other distros with kernels up to version 2.6.17 .
After disabling ipv6 and trying some basic diagnosis, I still have no idea what the problem
actually is.
Here are 2 examples of traceroutes, one from a Slackware current box, and the other one
from a PC running Dapper. (Both the hardware setups are identical, and running in the same network)

Slackware Current(2.6.21):
Ubuntu Dapper (2.6.15 IIRC):
Does anybody know what the problem could be? The only difference between the 2 computers is the kernel version, and I can't see how that would cause a problem (apart from new/changed features, which I'm probably not aware of).
I can visit some websites, e.g google.com, but not much else, so it obviously is not a DNS problem, and the fact that PCs using 'older' kernel versions have 'complete' access to the internet baffles me.

Thanks for any help:)

Have you checked if ip forwarding is enabled?

cat /proc/sys/net/ipv4/ip_forward

should return a 1

In fact, ip forwarding wasn't enabled, so I enabled it by adding it to my sysctl.conf file,
and after rebooting, it returned a 1.

However, I still have the same problem: It seems like the http requests are failing for many websites, notably, this site (linuxquestions.org), yahoo.com, slashdot.org... and most of the websites I visit (google.com works fine, as does gmail).

I'm beginning to think it's a problem with my router settings, although, can it really be, if PCs using older kernels (with the same hardware), and the PC running XP has no problems.

Why do you compare tcptraceroute and traceroute? Different things (one is upd, the other tcp, xp uses icmp)

Run a sniffer? Wireshark or tcpdump.

I don't see what ip_forward has to do here.