2 NICs problem

barghota · 07-18-2005, 10:54 AM

Hi, I have 2 NICs with these configuration...

Code:

# more /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
BOOTPROTO=static
IPADDR=192.168.1.3
NETMASK=255.255.255.0
NETWORK=192.168.1.0
BROADCAST=192.168.255.255
ONBOOT=yes
METRIC=10
MII_NOT_SUPPORTED=no
USERCTL=yes

# more /etc/sysconfig/network-scripts/ifcfg-eth1
DEVICE=eth1
BOOTPROTO=static
IPADDR=192.168.0.3
NETMASK=255.255.255.0
NETWORK=192.168.0.0
BROADCAST=192.168.255.255
ONBOOT=yes
METRIC=10
MII_NOT_SUPPORTED=no
USERCTL=yes

I have enabled port forward, configured the default gateway as 192.168.1.1 and configured iptables as follow:

Code:

# iptables -L -t nat
Chain PREROUTING (policy ACCEPT)
target     prot opt source               destination

Chain POSTROUTING (policy ACCEPT)
target     prot opt source               destination
MASQUERADE  all  --  anywhere             anywhere

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

My problem is when i ping from eth0 anything (example google.com) it pings but if i ping from eth1 anything (example google.com), the reply is destination host unreachable

Code:

# ping www.google.com -I eth0
PING www.l.google.com (66.249.85.99) from 192.168.1.3 eth0: 56(84) bytes of data.
64 bytes from 66.249.85.99: icmp_seq=1 ttl=248 time=111 ms
64 bytes from 66.249.85.99: icmp_seq=2 ttl=248 time=112 ms

Code:

# ping www.google.com -I eth1
PING www.l.google.com (66.249.85.104) from 192.168.0.3 eth1: 56(84) bytes of data.
From 192.168.0.3 icmp_seq=1 Destination Host Unreachable
From 192.168.0.3 icmp_seq=2 Destination Host Unreachable
From 192.168.0.3 icmp_seq=3 Destination Host Unreachable

I wish i could ping google from eth1. Thnx at least for reading this

keefaz · 07-18-2005, 11:16 AM

Sorry for asking, but why do you set eth1 on a different network ?
Maybe could you post a schema of your network ?

barghota · 07-18-2005, 05:15 PM

Ok, here is the situation, A router with IP 192.168.1.1, connected to my PC on eth0 which have static IP 192.168.1.3, and I have another PC having IP 192.168.0.4 which is connected to eth1 which have static IP 192.168.0.3.

When i ping www.google.com from the other PC it resolves the ip but returns host unreachable, also when i ping www.google.com from my PC using eth1 it resolves the IP but returns host unreachable. here is the routing table

Code:

# route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
192.168.1.0     *               255.255.255.0   U     10     0        0 eth0
192.168.0.0     *               255.255.255.0   U     10     0        0 eth1
default         192.168.1.1     0.0.0.0         UG    10     0        0 eth0

Also here is the output of # ifconfig

Code:

# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:0E:A6:34:18:04
          inet addr:192.168.1.3  Bcast:192.168.255.255  Mask:255.255.255.0
          inet6 addr: fe80::20e:a6ff:fe34:1804/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:611721 errors:0 dropped:0 overruns:0 frame:0
          TX packets:678408 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:400852089 (382.2 Mb)  TX bytes:187785752 (179.0 Mb)
          Interrupt:23 Base address:0xe800

eth1      Link encap:Ethernet  HWaddr 00:0C:41:22:44:29
          inet addr:192.168.0.3  Bcast:192.168.255.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:41ff:fe22:4429/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1204 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1012 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:90504 (88.3 Kb)  TX bytes:255919 (249.9 Kb)
          Interrupt:19 Base address:0xd800

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:5205 errors:0 dropped:0 overruns:0 frame:0
          TX packets:5205 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:352429 (344.1 Kb)  TX bytes:352429 (344.1 Kb)

sit0      Link encap:IPv6-in-IPv4
          inet6 addr: ::127.0.0.1/96 Scope:Unknown
          inet6 addr: ::192.168.1.3/96 Scope:Compat
          inet6 addr: ::192.168.0.3/96 Scope:Compat
          UP RUNNING NOARP  MTU:1480  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

And when i ping 192.168.1.3 from 192.168.0.3 i get also des host unreachable

Code:

# ping 192.168.1.3 -I eth1
PING 192.168.1.3 (192.168.1.3) from 192.168.0.3 eth1: 56(84) bytes of data.
From 192.168.0.3 icmp_seq=2 Destination Host Unreachable
From 192.168.0.3 icmp_seq=3 Destination Host Unreachable
From 192.168.0.3 icmp_seq=4 Destination Host Unreachable

broch · 07-18-2005, 09:46 PM

you need to setup bridging (this would require custom kernel with CONFIG_BRIDGE=y)

barghota · 07-19-2005, 04:07 AM

I made it once without bridging the the network was fine, i just want eth1 to ping eth0, if someone could plzz give me a hint.

broch · 07-19-2005, 07:11 AM

then try NAT