tcptraceroute

When using tcptraceroute to trace the route to a machine on tcp port
80, I get only three hops back:

$ tcptraceroute -n www.google.com 80
Selected device ppp0, address 209.96.232.204 for outgoing packets
Tracing the path to www.google.com (216.239.33.99) on TCP port 80, 30
hops max
1 206.246.195.73 (206.246.195.73) 150.084 ms 149.233 ms 149.114
ms
2 206.246.195.126 (206.246.195.126) 149.462 ms 149.189 ms 149.468
ms
3 216.239.33.99 (216.239.33.99) [open] 149.057 ms 148.308 ms
149.273 ms

When using another port, or using "traceroute -I", I get the normal
10-20 hops.

This works for any target host.... What is going on?

-t?

On 12 Aug 2003 16:23:19 -0700,
beltorak ((E-Mail Removed)) wrote:
> When using tcptraceroute to trace the route to a machine on tcp port
> 80, I get only three hops back:
>
> $ tcptraceroute -n www.google.com 80
> Selected device ppp0, address 209.96.232.204 for outgoing packets
> Tracing the path to www.google.com (216.239.33.99) on TCP port 80, 30
> hops max
> 1 206.246.195.73 (206.246.195.73) 150.084 ms 149.233 ms 149.114 ms
> 2 206.246.195.126 (206.246.195.126) 149.462 ms 149.189 ms 149.468 ms
> 3 216.239.33.99 (216.239.33.99) [open] 149.057 ms 148.308 ms 149.273 ms
>
> When using another port, or using "traceroute -I", I get the normal
> 10-20 hops.
>
> This works for any target host.... What is going on?

I think it is pretty obvious. Your network provider/ISP has a
transparent HTTP proxy. Any traffic to TCP port 80 is transparently
redirected to the proxy, which is three hops away from your IP address.

Bev
--
Bev A. Kupf
"The lyfe so short, the craft so long to lerne" -- Chaucer