ADSL connection problems

[WonderBob]

Hi,

my ADSL line is acting a bit funny

under normal circumstances when the line goes down and I ping any URL or domain i get a "unknown host" reply.

but at the moment If I ping google.com for instance, it will show me the IP address, but then not recieve any packets in return.

So am i right in thinking that there is a connection but something is going wrong somehere down the line.

I can get IP address for any URL I ping, but dont get any packets in return.

Does anybody know why this would happen? Can it be something on my side that has gone wrong?

 

[Franna]

There is a very simple answer - most content provider websites block ICMP traffic (aka ping traffic) on their firewalls.

For example:
www.google.com does not block ping traffic, hence the packets received.
www.ibm.com does block ping traffic, therefore only the IP is returned.
www.news24.co.za also blocks ping traffic, therefore only the IP is returned.

If you get "Request timed out" during a ping it can also mean that the packet was not received back in 2000ms. When international is slow this default timeout can be avoided by using the command: "ping www.google.com -w 9999". The maximum two-way wait time is then increased to 9999ms.

 

[WonderBob]

usually I have no problem with pings to any domain.

I dont get a "request timed out" response either.

I am doing the ping requests from a linux box, which acts as my ADSL router/modem. I can see that the ADSL is connected, and it seems that when I send ping requests the packets gets transmitted but nothing comes back.

i.e.

PING google.com (64.233.187.99) 56(84) bytes of data.

will sit there until I hit ctrl-c

and then display

--- google.com ping statistics ---
162 packets transmitted, 0 received, 100% packet loss, time 160975ms


previously when our ADSL was down all i received on pings was a unknown host message.

Would think that this points to a problem on the ADSL network or with something on telkoms side, but they cant find any problems (or so they say)