Router problems on Redhat 9.0 Linux 2.4.20-13.9.HOSTAP

Yann Garcia yann.garcia at smartcom.com
Fri Apr 23 08:36:49 UTC 2004



-----Message d'origine-----
De : Pete Nesbitt [mailto:pete at linux1.ca] 
Envoyé : vendredi 23 avril 2004 02:40
À : yann.garcia at smartcom.com; General Red Hat Linux discussion list
Objet : Re: Router problems on Redhat 9.0 Linux 2.4.20-13.9.HOSTAP

On April 22, 2004 12:18 am, Yann Garcia wrote:
> -----Message d'origine-----
> De : Pete Nesbitt [mailto:pete at linux1.ca]
> Envoyé : jeudi 22 avril 2004 04:28
> À : yann.garcia at smartcom.com; General Red Hat Linux discussion list
> Objet : Re: Router problems on Redhat 9.0 Linux 2.4.20-13.9.HOSTAP
>
> On April 21, 2004 12:40 am, Yann Garcia wrote:
> <snip....>
>
> > On April 15, 2004 12:21 am, Yann Garcia wrote:
> > > Hi,
> > >
> > > On my Linux box, I have two network interfaces: a LAN interface
>
> (eth0)
>
> > and
> >
> > > a WLAN (wlan0). I set ip forwarding in /etc/sysctl.conf. I start a
> >
> > sniffer
> >
> > > (tethereal) on both interfaces. When I make a ping from WLAN
network
> >
> > to LAN
> >
> > > network, ping don' cross my gateway. The networks infos are:
> > > eth0: 10.0.1.37/16
> > > wlan0: 10.0.10.1/24
> > > The route tables are (netstat -rn):
> > >          Destination     Passerelle      Genmask         Indic
MSS
> > > Fenetre irtt Iface 10.0.10.0       0.0.0.0         255.255.255.0
U
> > >
> > >  0 0          0 wlan0 10.0.0.0        0.0.0.0         255.255.0.0
> >
> > U
> >
> > >     0 0          0 eth0 169.254.0.0     0.0.0.0
255.255.0.0
> >
> > U
> >
> > >       0 0          0 wlan0 127.0.0.0       0.0.0.0
255.0.0.0
> > >
> > > U         0 0          0 lo 0.0.0.0         10.0.0.1
0.0.0.0
> > >
> > > UG        0 0          0 eth0
> > >
> > > The iptables rules are (iptables -L -n -v):
> > >          Chain INPUT (policy ACCEPT 17346 packets, 1205K bytes)
> > >           pkts bytes target     prot opt in     out     source
> > >
> > >  destination
> > >
> > >          Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
> > >           pkts bytes target     prot opt in     out     source
> > >
> > >  destination
> > >
> > >          Chain OUTPUT (policy ACCEPT 17144 packets, 1306K bytes)
> > >           pkts bytes target     prot opt in     out     source
> > >
> > >  destination
> > >
> > > I'm sorry but I don't understand why my gateway doesn't work!
> > >
> > > Thank you very much for your assistance,
> > >
> > > Best regards,
> > >
> > > Yann Garcia
> > > Software Engineer
> >
> > Hi,
> > Your eth0's network contains of the wlan IP range.
> > 10.0.1.37/16 is part of a network ip range of 10.0.0.1 to
10.0.255.254
> > Your wlan range is inside that so no routing is performed.
> >
> > You want to use a class C range for the wlan, so instead of
10.0.10.0
> > network,
> > try using one of the 192.168. class C networks. It may make be best
to
> > use 2
> > different 192.168 networks (say 192.168.0.0/24 for LAN and
> > 192.168.1.0/24 for
> > the WLAN).
> >
> > Class A 1.0.0.0 - 127.255.255.255
> > Class B 128.0.0.0 - 191.255.255.255
> > Class C  192.0.0.0 - 223.255.255.255
> >
> > Hope that helps.
> > --
> > Pete Nesbitt, rhce
> >
> >
> >
> >
> >
> > Hi Pete
> >
> >
> > I use 10.1.10.0 as network for my wlan0 interface. The both
interfaces
> > seam to be ok: I can run telnet on each network (LAN on eth0 and
WLAN
>
> on
>
> > wlan0). But the problem persists: it's impossible to ping a machine
on
> > LAN area (10.0.2.201) from a machine in WLAN area (10.1.10.2).
> > The interfaces configurations are:
> > Eth0:
> >         InetAddr: 10.0.1.37/16
> >         Network: 10.0.1.0
> >         Broadcast: 10.0.1.255
> > Wlan0:
> >         InetAddr: 10.1.10.1/24
> >         Network: 10.1.10.0
> >         Broadcast: 10.1.10.255
> >
> > L'IP forwarding is active (echo 1 > /proc/sys/net/ipv4/ip_forward).
> >
> > The netstat -rn output is:
> > Table de routage IP du noyau
> > Destination   Passerelle    Genmask       Indic   MSS Fenêtre irtt
> > Iface
> > 10.1.10.0     0.0.0.0       255.255.255.0   U         0 0          0
> > wlan0
> > 10.0.0.0      0.0.0.0       255.255.0.0     U         0 0          0
> > eth0
> > 169.254.0.0   0.0.0.0       255.255.0.0     U         0 0          0
> > wlan0
> > 127.0.0.0     0.0.0.0       255.0.0.0       U         0 0          0
>
> lo
>
> > 0.0.0.0       10.0.0.1      0.0.0.0         UG        0 0          0
> > eth0
> >
> > The iptables --numeric --verbose --List output is:
> > Chain INPUT (policy ACCEPT 76 packets, 5196 bytes)
> >  pkts bytes target   prot opt in   out     source
> > destination
> >
> > Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
> >  pkts bytes target   prot opt in   out     source
> > destination
> >     0     0 ACCEPT     all  --  *      *       0.0.0.0/0
> > 0.0.0.0/0
> >
> > Chain OUTPUT (policy ACCEPT 76 packets, 5196 bytes)
> >  pkts bytes target   prot opt in     out     source
> > destination
> >
> >
> > I don't understand what happen!!???
> > Please, can you help me?
> >
> > Thank you very much,
> >
> > Cheers,
> >
> > Yann Garcia
> >
> >
> > I'm not sure but I think that my first reply didn't reach RH disc.
>
> list
>
> > so I'll post it again.
> >
> > The network from eth0 isn't correct: it should be 10.0.0.0 for IP
with
> > /16 mask.
> >
> > Oups, I make a key error: I agree with you, for eth0, the network is
> > 10.0.0.0 (not 10.0.1.0) and the broadcast is 10.0.255.255.
> > I'm sorry !
> > Here are the ifcfg-eth0 & ifcfg-wlan0:
> >
> > # Please read /usr/share/doc/initscripts-*/sysconfig.txt
> > # for the documentation of these parameters.
> > USERCTL=no
> > PEERDNS=yes
> > GATEWAY=10.0.0.1
> > TYPE=Ethernet
> > DEVICE=eth0
> > #BOOTPROTO=none
> > BOOTPROTO=dhcp
> > NETMASK=255.255.0.0
> > ONBOOT=yes
> > DHCP_HOSTNAME=10.0.2.201
> > #IPADDR=10.0.3.1
> > NETWORK=10.0.0.0
> > BROADCAST=10.0.255.255
> >
> >
> > # Please read /usr/share/doc/initscripts-*/sysconfig.txt
> > # for the documentation of these parameters.
> > DEVICE=wlan0
> > BOOTPROTO=static
> > ONBOOT=yes
> > IPADDR=10.1.10.1
> > NETMASK=255.255.255.0
> > NETWORK=10.1.10.0
> > BROADCAST=10.1.10.255
> >
> > Cheers,
> >
> > Yann
> >
> >
> > Bottom line: is it working now? :)
> >
> >
> > Hi,
> > No, I already have the same problem. I check all network config.
>
> files:
> > I use 10.1.10.0 as network for my wireless network.
> > When I’m connected to the WLAN, the DHCP server gives me a right
> > address, I can ping the wlan0 interface (10.1.10.1) and the eth0
> > interface 10.0.1.37.
> > But I can’t ping the LAN gateway (10.0.0.1). The tethereal output
> > (tetherearl –i eth0 –V –N –mnt) on eth0 doesn’t log any request
coming
> > from my wireless station.
> > Cheers,
> > Yann
>
> HI Yan,
> I'm having a little trouble following the thread (there is no
indication
> when
> the senter changes, not sure why).
> The machines on the wireless network should have the default gateway
of
> 10.1.10.1, while the machines on LAN including the linux box/router,
> should
> have 10.0.0.1 as the gateway.
>
> From your last post, it looks like the you can ping from a machine on
> the WLAN
> through the linux box to it's LAN nic. Is that correct?
>
> Can you ping the 10.0.0.1 gateway from the linux box?
>
> Can you ping anything else in the LAN from the WLAN?
>
> Can the LAN machines ping the WLAN machines?
>
> Does 'cat /proc/sys/net/ipv4/ip_forward' on the linux box still show
> "1"?
> --
> Pete Nesbitt, rhce
>
>
>
> Hi Pete,
>
> My problem is that I can't ping machine in the LAN from the WLAN. I
> start tethereal on each network interface on my linux box (eth0 &
> wlan0). When I try to ping a machine on the LAN from the WLAN, I can
see
> the ping request on the wlan0 interface. But I don't see anything on
the
> eth0 interface.
>
> Yes, the machines on the wireless network have the default gateway of
> 10.1.10.1, while the machines on LAN including the linux box/router,
> have 10.0.0.1 as the gateway.
>
> From the linux box, I can ping the gateway and all other machine in
the
> LAN.
> But from the WLAN, I can only ping the linux box interface eth0. I
can't
> ping the gateway 10.0.0.1 and I can't ping any machine in the LAN.
>
> Yes, the ip_forwarding is set:
> [root at hotspot root]# cat /proc/sys/net/ipv4/ip_forward
> 1
>
> Here is the output of ifconfig:
> eth0      Lien encap:Ethernet  HWaddr 00:08:74:C2:93:35
>           inet adr:10.0.1.37  Bcast:10.0.255.255  Masque:255.255.0.0
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:200395 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:10625 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 lg file transmission:100
>           RX bytes:36890115 (35.1 Mb)  TX bytes:818892 (799.6 Kb)
>           Interruption:11 Mémoire:dd000000-dd001080
>
> lo        Lien encap:Boucle locale
>           inet adr:127.0.0.1  Masque:255.0.0.0
>           UP LOOPBACK RUNNING  MTU:16436  Metric:1
>           RX packets:644548 errors:0 dropped:0 overruns:0 frame:0
>           TX packets:644548 errors:0 dropped:0 overruns:0 carrier:0
>           collisions:0 lg file transmission:0
>           RX bytes:44069581 (42.0 Mb)  TX bytes:44069581 (42.0 Mb)
>
> wlan0     Lien encap:Ethernet  HWaddr 00:09:5B:91:54:AE
>           inet adr:10.1.10.1  Bcast:10.1.10.255  Masque:255.255.255.0
>           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
>           RX packets:2162741 errors:0 dropped:194 overruns:0 frame:0
>           TX packets:10994 errors:16 dropped:0 overruns:0 carrier:0
>           collisions:0 lg file transmission:100
>           RX bytes:14323112 (13.6 Mb)  TX bytes:1641798 (1.5 Mb)
>           Interruption:5 Mémoire:d0935000-d0936000
>
> Yann Garcia


Hi Yann,
If you can ping 10.0.1.37 from the WLAN, then your Linux box is routing.
What is the error message that the wlan machines receive when the ping
fails?
You may want to try running tcpdump on the eth0 and check
/var/log/messages 
for any FW generated errors messages.
-- 
Pete Nesbitt, rhce


Hi Pete,

The error message when I ping a LAN machine (the gateway for instance)
from a WLAN machine is 'Time exceed'.

I run tcpdump on eth0 and I make a ping from WLAN to LAN and I have net
error on /var/log/messages: there are no messages between the both
messages 'device eth0 entered in promiscuous mode' (tcpdump started) and
'device eth0 left promiscuous mode' (tcpdump stopped).

Cheers,

Yann






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