Natty cannot ping

[Nathanael]

I have a small home network, as follows:

ZyXEL wireless router
laptop, ugraded to Natty from 10.10, wireless connection
desktop, fresh Natty install, wired connection
HTC Desire cellphone, Android 2.2, wireless connection

IPs are assigned via DHCP, with the router currently open (no security). The only firewall configuration that has been done is to port-forward port 80 to 192.168.1.101

Internet is working for all machines, and all machines can ping the router. In addition, the laptop and the phone can ping each other. The problem is the desktop, which can neither ping nor be pinged by anybody (except the router).

Network settings has no configured connections. I tried setting up a connection manually, to no avail.

On the desktop:

$ ifconfig

eth0  Link encap:Ethernet HWaddr 00:18:f3:69:04:46 
     inet addr:192.168.1.103 Bcast:192.168.1.255 Mask:255.255.255.0
     inet6 addr: fe80::218:f3ff:fe69:446/64 Scope:Link
     UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
     RX packets:2352 errors:0 dropped:0 overruns:0 frame:0
     TX packets:3381 errors:0 dropped:0 overruns:0 carrier:0
     collisions:0 txqueuelen:1000 
     RX bytes:1843144 (1.8 MB) TX bytes:552882 (552.8 KB)
     Interrupt:23 Base address:0xa000

$ cat /etc/networks/interfaces

auto lo
iface lo inet loopback

$ sudo iptables -L

Chain INPUT (policy ACCEPT)
target   prot opt source        destination     

Chain FORWARD (policy ACCEPT)
target   prot opt source        destination     

Chain OUTPUT (policy ACCEPT)
target   prot opt source        destination

$ sudo ufw status
Status: inactive

What else?

--Nathanael

[kubicle]

Re: Natty cannot ping

At least some routers disable traffic between LAN and WLAN interfaces by default for security reasons, and the symptoms you describe seem to fit that (WLAN clients can ping each other but not a LAN client, and vice versa...and all can ping the router).

I'd check your router settings for bridging between LAN and WLAN. If you can't find a setting for it, try googling with your router model and WLAN to LAN connection, or something similar.

EDIT: you can check whether this is indeed the issue by connecting your laptop temporarily via ethernet cable (LAN) and see if ping works with your desktop, as they are both on LAN.

[Nathanael]

Re: Natty cannot ping

Thanks for the reply.

you can check whether this is indeed the issue by connecting your laptop temporarily via ethernet cable (LAN) and see if ping works with your desktop, as they are both on LAN

[EDIT: I don't see anything in the router configuration relating to LAN/WLAN interfacing. Also, I misread the original sentence.]

Both my laptop and my cellphone connect via wlan, and they can ping each other. However, I plugged in the laptop and turned off the wireless. ifconfig shows only eth2 and lo interfaces.

Same result, unfortunately: the laptop and cellphone can ping each other, the desktop can only ping the router and the Internet.

--Nathanael