Hi,
This is being done on a linux PC with three interfaces.* Ignore interface
eth0.* The linux PC connects to a switch that connects it to the rest of my
network.. *Eth1 and eth1:1* is are external facing interfaces with public
I.Ps. Eth3 is facing my internal network with a private I.P address.
The *problem* is: When the internal interface (eth3) is up, I cannot reach
the rest of my public network from eth1:1 and cannot reach the internal
network too using eth3.
However, with the internal interface down, eth3 in this case, I can reach
the rest of my network from both interfaces eth1 and eth1:1
How can I keep both my external interfaces and internal interface up and
still be able to reach the rest of the network (External network) and my
internal hosts (that use private I.Ps) too?
The output of route -n
Destination Gateway Genmask Flags Metric Ref Use
Iface
196.43.133.64 0.0.0.0 255.255.255.192 U 0 0
0 eth1
192.168.2.0 0.0.0.0 255.255.255.0 U 0
0 0 eth0
172.16.0.0 0.0.0.0 255.255.0.0 U 0
0 0 eth3
169.254.0.0 0.0.0.0 255.255.0.0 U 1000
0 0 eth0
0.0.0.0 172.16.0.1 0.0.0.0 UG 100
0 0 eth3
0.0.0.0 196.43.133.65 0.0.0.0 UG 100
0 0 eth1
0.0.0.0 192.168.2.1 0.0.0.0 UG 100
0 0 eth0
My Interfaces are configured as below:
eth1 Link encap:Ethernet HWaddr 00:e0:81:2b:0a:c3
inet addr:196.43.133.106 Bcast:196.43.133.127
Mask:255.255.255.192
inet6 addr: fe80::2e0:81ff:fe2b:ac3/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1354 errors:0 dropped:900846 overruns:0 frame:0
TX packets:1254 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:137539 (137.5 KB) TX bytes:133686 (133.6 KB)
Interrupt:25
eth1:1 Link encap:Ethernet HWaddr 00:e0:81:2b:0a:c3
inet addr:196.43.133.109 Bcast:196.43.133.127
Mask:255.255.255.192
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:25
eth3 Link encap:Ethernet HWaddr 00:04:23:08:91:dd
inet addr:172.16.0.10 Bcast:172.16.255.255 Mask:255.255.0.0
inet6 addr: fe80::204:23ff:fe08:91dd/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:12439091 errors:0 dropped:0 overruns:0 frame:0
TX packets:629185 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:100
RX bytes:1006167150 (1.0 GB) TX bytes:60553805 (60.5 MB)
Is that clear enough? :)
On Tue, Feb 22, 2011 at 4:39 PM, Simon Vass <[email protected]> wrote:
> Are you trying to build a firewall? Is this on a device or a PC?
>
>
>
> Simon Vass
> Managing Director
> E-Tech Uganda Ltd
>
> http://www.etech.ug
> Tel: +256 (0) 312260620 or (0) 312260621
> email: [email protected]
> skype: e-techservicedesk
>
>
> ----- Original Message -----
> From: "Richard Zulu" <[email protected]>
> To: "Uganda Linux User Group" <[email protected]>
> Sent: Tuesday, 22 February, 2011 1:19:37 PM
> Subject: [LUG] IP Routing Multiple interfaces
>
>
> Hi,
>
> Quick question: I have a linux box with three interfaces, two of them face
> my external network (one is a sub-interface) , with the same gateway address
> but obviously different I.Ps. Both are in the same public network / subnet
>
> One of the interfaces faces my internal network, private IP addresses.
>
> Problem: With all the interfaces up, I cannot reach any of the networks,
> both internal and external.
>
> However, with the internal network interface down, I can get to the
> external network.
>
> I need my internal interface up so that I can get to my internal network
> and at the same time get to the external networks.
>
> How can I pull it off?
>
>
>
> --
> Richard Zulu
> gtug lead, Kampala (Uganda)
> http://kampala.gtugs.org
>
>
>
> _______________________________________________
> The Uganda Linux User Group: http://linux.or.ug
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> _______________________________________________
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> Send messages to this mailing list by addressing e-mails to:
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--
Richard Zulu
gtug lead, Kampala (Uganda)
http://kampala.gtugs.org
_______________________________________________
The Uganda Linux User Group: http://linux.or.ug
Send messages to this mailing list by addressing e-mails to: [email protected]
Mailing list archives: http://www.mail-archive.com/[email protected]/
Mailing list settings: http://kym.net/mailman/listinfo/lug
To unsubscribe: http://kym.net/mailman/options/lug
The Uganda LUG mailing list is generously hosted by INFOCOM:
http://www.infocom.co.ug/
The above comments and data are owned by whoever posted them (including
attachments if any). The mailing list host is not responsible for them in any
way.
