Routing Problem

[Thomas Foster]

Sounds like the man page for routed might be what you seek

http://www.freebsd.org/cgi/man.cgi?query=routed&sektion=8

T

----- Original Message ----- 
From: "Gustafson, Tim" <tjg at meitech.com>
To: "Thomas Foster" <tbonius at comcast.net>
Cc: <questions at freebsd.org>
Sent: Wednesday, February 02, 2005 5:02 AM
Subject: RE: Routing Problem


> Thomas (and John too),
> 
> Let me clarify a little bit.
> 
> What I have is this:
> 
> A single FreeBSD web server with a single NIC in it
> Two T1 routers, each with a different subnet.
> 
> My FreeBSD box has two IP addresses assigned to it, one from the first
> subnet and one from the second subnet.
> 
> I want to use round-robin DNS to direct half my web traffic to the first
> IP and half to the second IP.
> 
> As I said to John in a private e-mail earlier this morning, I have a
> Windows 2000 box that is doing exactly this with these two subnets right
> now.  I know it "can" be done.  I have a feeling that the FreeBSD TCP
> stack lacks the capability.  By the way, this also works with Cisco
> hardware.  I have used Cisco equipment in this same configuration in the
> past.
> 
> I think they way it SHOULD work is that you should be able to give a
> FreeBSD box multiple default gateways.  When FreeBSD gets a packet to an
> IP on the first subnet, it should use the default gateway that is also
> on that subnet.  When FreeBSD gets a packet to an IP on the second
> subnet, it should use the second default gateway.  This seems to be the
> logic that Windows (and Cisco) uses.
> 
> Tim Gustafson
> MEI Technology Consulting, Inc
> tjg at meitech.com
> (516) 379-0001 Office
> (516) 480-1870 Mobile/Emergencies
> (516) 908-4185 Fax
> http://www.meitech.com/ 
> 
> 
> 
> -----Original Message-----
> From: Thomas Foster [mailto:tbonius at comcast.net]
> Sent: Wednesday, February 02, 2005 7:57 AM
> To: Gustafson, Tim
> Cc: questions at freebsd.org
> Subject: Re: Routing Problem
> 
> 
> Hi Tim..
> 
> If you have multiple interfaces and you configure a default gateway for
> each 
> interface, the default metric determination that is based on the speed
> of 
> the interface usually uses the fastest interface for default gateway 
> traffic. This is usually desirable in configurations in which the
> computer 
> is connected to the same network.
> 
> This behavior can become a problem when the computer exists on two or
> more 
> disjointed networks (networks that do not provide symmetric reachability
> on 
> layer3). Symmetric reachability exists when packets can be sent to and 
> received from an arbitrary destination.
> 
> Because the TCP/IP version4 protocol uses a single default route in 
> FreeBSD's routing table at any one time for default route traffic,
> default 
> routers configured on multiple interfaces connected to two or more 
> disjointed networks can wreak routing traffic havoc.
> 
> In FreeBSD, you can manually configure the routing table for the
> individual 
> interfaces..  but it sounds to me as if you are attempting to use two 
> ethernet interfaces connected to two disjointed networks connected to 
> routers with two seperate subnets in order to balance http requests to
> one 
> server.. is this the case?  I guess I am not fully understanding your 
> configuration ...
> 
> T.
> 
> 
> ----- Original Message ----- 
> From: "Gustafson, Tim" <tjg at meitech.com>
> To: "Thomas Foster" <tbonius at comcast.net>
> Cc: <questions at freebsd.org>
> Sent: Wednesday, February 02, 2005 4:06 AM
> Subject: RE: Routing Problem
> 
> 
>> Thomas,
>>
>> No, I'm not using this box as a router.  It is a web server, and I
> need
>> to spread the load of my web traffic across two separate T1s.
>>
>> I can't just add routes.  You need a default route, or parts of the
>> internet would become inaccessible.  In my case, you need TWO default
>> routes.  I have set up Cisco equipment and Windows workstations with
> two
>> default routes in the past, and it has worked.  In fact, I have one
>> Windows box right now that is configured on both these networks with
> two
>> default gateways, and it is working.
>>
>> There has to be a way to make it work on FreeBSD.
>>
>> Tim Gustafson
>> MEI Technology Consulting, Inc
>> tjg at meitech.com
>> (516) 379-0001 Office
>> (516) 480-1870 Mobile/Emergencies
>> (516) 908-4185 Fax
>> http://www.meitech.com/
>>
>>
>>
>> -----Original Message-----
>> From: Thomas Foster [mailto:tbonius at comcast.net]
>> Sent: Wednesday, February 02, 2005 4:48 AM
>> To: Gustafson, Tim
>> Cc: questions at freebsd.org
>> Subject: Re: Routing Problem
>>
>>
>> Im confused.. if you have two T1s, then are using /30s dor the ranges?
>> If
>> so.. what about not giving a default gateway for either one and just
> add
>>
>> routes...
>>
>> Are you attempting utilize this as just a router.?
>>
>> Theres a section that covers setting up routing on interfaces in the
>> handbook:
>>
>>
> http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/network-routin
>> g.html
>>
>> Hope this helps
>>
>> T
>> ----- Original Message ----- 
>> From: "Gustafson, Tim" <tjg at meitech.com>
>> To: <freebsd-questions at freebsd.org>
>> Sent: Tuesday, February 01, 2005 5:35 PM
>> Subject: Routing Problem
>>
>>
>>>I am having a problem setting up a multi-homed host.  I have two
>>> separate T1 internet connections, and one physical NIC in my FreeBSD
>>> box.  The two networks are as follows:
>>>
>>> Connection 1:
>>> LAN Address: 1.2.3.24/25
>>> Router Address: 1.2.3.1
>>>
>>> Connection 2:
>>> LAN Address: 4.5.6.106/29
>>> Router Address: 4.5.6.105
>>>
>>> I would like to set up my FreeBSD box so that I can connect to either
>>> LAN address from the outside world.  The problem is that I cannot
>>> specify two default gateways.  Right now, I have 1.2.3.1 set up as a
>>> default gateway, and I can get to the 1.2.3.24 IP from the outside
>>> world.  However, I can't get to 4.5.6.106.  I can't even ping it.
>> From
>>> the FreeBSD box, I can ping 4.5.6.105, and from the outside world I
>> can
>>> ping 4.5.6.105, but I can't ping 4.5.6.106 from the outside world.
>>>
>>> Is there any way to make this work?  How can I make FreeBSD have two
>>> default gateways?  I read somewhere about being able to set up source
>>> routing, but I haven't been able to find any HOWTO's about that.
>>>
>>> Any help is greatly appreciated.
>>>
>>
>>
>> 
> 
> 
>