Network

Obie · 08-08-2004, 12:08 AM

I recently installed Mandrake 10 and have problems with pinging my network card as well as localhost. It can't seem to reach either one. There isn't anything wrong with my network card as it works fine with Red Hat. I thought it may have been iptables or shorewall firewall rules so I shut them down and tried pinging again however to no avail. Can someone please tell me what is wrong and what I can do to rectify it?

adz · 08-08-2004, 02:10 AM

Well have you brought the interface up? Whow does the output of ifconfig look like? While we're at it, what does lspci look like.

Obie · 08-08-2004, 03:28 AM

adz,

Yes it is up and I did run ifup eth0. Now the strange thing is having gone through various other forums, I managed to find the source of the issue. It was the sysctl.conf file. It was blocking all icmp requests so I changed the value to 0 rather than 1. Now I can ping both the localhost and eth0. I am however unable to ping any other PC on the network. What would prevent that from occuring?

Thanks

adz · 08-08-2004, 03:46 AM

A firewall or a routing problem. Can you post the output of route -n?

Obie · 08-08-2004, 04:15 AM

adz,

The details from route -n are noted below:
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
127.0.0.0 0.0.0.0 255.0.0.0 U 0 0 0 lo

adz · 08-08-2004, 07:06 PM

It seems that you don't have a default gateway. What does your network topology look like? Is there a DHCP server on your network? What device is connected directly to the network card of your computer?

Obie · 08-08-2004, 08:41 PM

adz,

The reason I don't have a Gateway is because I don't require one. I have a cross over cable attached to the PC running Mandrake adjoining another PC. They are on the same network address i.e. 192.168.0.0 and subnetmask.

adz · 08-08-2004, 08:57 PM

So neither computer can ping the other?

Try using ping -r <IP address>. See if that works.

Obie · 08-08-2004, 09:03 PM

adz,

That is correct. Neither computer can ping one another. I'll try ping -r <IP address> but don't see how that would help as it only counts the number of hops. I think it has to do with msec blocking outgoing and incoming icmp requests. Would you know how to configure msec? Mandrake's documentatiion is hopeless.

adz · 08-08-2004, 09:22 PM

From the ping manpage:

Code:

     -r      Bypass the normal routing tables and send directly to a host on
             an attached network.  If the host is not on a directly-attached
             network, an error is returned.  This option can be used to ping a
             local host through an interface that has no route through it
             (e.g., after the interface was dropped by routed(8)).

Maybe yours is different to mine. I've noticed differences before like some people (Red Hat, I think) having a "-b" switch which I don't.

Obie · 08-08-2004, 09:24 PM

adz,

I'll look up on the mandrake man pages. Any advice on msec?

adz · 08-08-2004, 09:28 PM

No sorry. Never used Mandrake.

Obie · 08-08-2004, 09:30 PM

adz,

thanks for your help so far. hopefully i'll find something I can work with.

Obie · 08-08-2004, 09:32 PM

adz,

How are:
accept_broadcasted_icmp_echo(arg)
accept_icmp_echo(arg)
different?

adz · 08-08-2004, 09:55 PM

Well one's a broadcast, the other isn't. The non-broadcast one will be addressed to a specific node on the network. The broadcast will be addressed to a range of nodes but no one in particular. Does that clear it up for you? Feel free to ask if you need more info.