strange response from traceroute...

[zioponics]

Hello All,

I'm sure if this is the right forum, but anyway...

I have an ADSL router (Alcatel SpeedTouch Pro) and I can connect to the Internet without any probs.

But since one or two months, I've noticed that when I do a "tracert what.you.want.com" the first hop is my router, but the second is a "Request timed out." message.


1 <10 ms <10 ms <10 ms 10.0.0.138
2 * * * Request timed out.
3 and then it continues without problems....


What does that mean? Is my ISP that have some problems? I've phoned to the customer service and the operator was really surprised to notice that even his machine was acting like mines.

Does anybody knowns what's going on my ISP Nework??
Is something wrong with DNS configuration?

GreatThanks
zioponics

 

[gunthnp]

the routers at your ISP or that hop are not responding to icmp thats all
alot people don't like their router sending icmp out

gunthnp

 

[Comstocb]

Expanding on the last post, firewalls in the route path will act this way as well as they are typically set up not to return ICMP information when traditionally required.

Brian

 

[pansophic]

Yes, but a firewall will typically drop the ICMP traffic altogether, so all hops after the firewall also show no response. A device that is configured to not respond to ICMP packets (like a router in this case) will only drop the packets that are intended for it. If the packet is intended for another device down the line, they will forward it normally.

It is not all that unusual to see a dropout like this during a traceroute.


pansophic

 

[zioponics]

Thanks guys!

So that's why my packets size is always 28 bytes bigger, when I change the MTU value and then test with a
&quot;ping -l xxxx&quot;...

I thinking that I'm too paranoid...

Regards
zioponics

 

[bcastner]

The MTU = ping value + 28 bytes of overhead