How to ping on 2 different subnets from clients

voncloft · Tux's lil' helper Joined: 29 Jan 2014 Posts: 99

My clients via ethernet-non wireless are on the subnet 192.168.1.x

My wireless....are on 192.168.42.x

I have a router I created with 3 cards (with Gentoo on it)

1x Wan - ethernet - dhcp from ISP
1x Lan - ethernet - 192.168.1.1
1x Wifi Card - 192.168.42.1

How do I ping from PC "A" which is 192.168.1.100 and ping my laptop 192.168.42.2

I am just getting my feet wet with networking - I got wifi working with hostapd ... but I can't ping my laptop from my ethernet connected PC.

Any guides? Google isn't returning much.

Thanks

eccerr0r · Posted: Wed Feb 07, 2018 4:31 am Post subject:

What are your network masks?

It should just 'work' if you have netmasks on your LANs (wl and wired) to 255.255.255.0 and you have forwarding enabled which you should, if NAT is working...
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Ant P. · Watchman Joined: 18 Apr 2009 Posts: 6920

You need to enable IPv4 forwarding on the router, it's off by default unless some routing daemon turns it on:

voncloft · Tux's lil' helper Joined: 29 Jan 2014 Posts: 99

voncloft · Tux's lil' helper Joined: 29 Jan 2014 Posts: 99

bbgermany · Posted: Wed Feb 07, 2018 11:25 am Post subject:

Hi,

Do you have traceroute installed on one of the clients? If yes, can you post the output from traceroute to one of the other unreachable clients? An can you post the output of your firewall rules? Maybe there can be a problem as well.

greets, bb
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voncloft · Tux's lil' helper Joined: 29 Jan 2014 Posts: 99

voncloft · Tux's lil' helper Joined: 29 Jan 2014 Posts: 99

szatox · Advocate Joined: 27 Aug 2013 Posts: 3495

I suppose it's a routing problem on the remote client.
It probably doesn't know it is connected to a router. E.g. no default gw defined.

What does `ip route` say?
What does ip -o a say?

If you can't spot any mistakes there, consider pasting the results from all 3 machines. You can anonymize wan interface, it's irrelevant

Edit: is this iptables dump from your rotuer or from client?
Also, does it work if you disable all firewalls along the way?

voncloft · Tux's lil' helper Joined: 29 Jan 2014 Posts: 99

szatox · Advocate Joined: 27 Aug 2013 Posts: 3495

THis one is your lcoal client, isn't it?
The remote one would be 192.168.42.2, since this is the one that does not respond.

Finally, there is that ultimate weapon for network troubleshooting: wireshark (or tcpdump in text mode though it's not as user friendly). Launch it on the remote client and see if it receives anything and attempts to reply.

eccerr0r · Posted: Thu Feb 08, 2018 12:17 am Post subject:

Can you flush all your forward table rules, change it to default ACCEPT, and then see if it works?
You shouldn't need iptables on your non-router machines...

Also what's your route table look like on the router? And what is bond0? You have a more complicated setup than what seems to be implied...
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Hu · Administrator Joined: 06 Mar 2007 Posts: 23091

According to your iptables -L output, failure is expected. Your first two rules are identical (unless iptables is lying to you, which it probably is, which is why I always tell people to use iptables-save -c instead, but no one ever learns) and direct it to drop traffic that you say you want passed.