[LARTC] @home cable modem

[LARTC] @home cable modem

[Josh Sides]

AT&T at home will provide multiple IP addresses, but they do not guarentee
that they will be in the same subnet.  I requested two additional ip's so of
course now I have ip's in three different subnets.

With Windows I know it is only possible to have 1 active default route.

Is there anyway to put all three ip's on one linux machine and have the
internet have the ability to deliver packets to all three?

Thanks
Josh


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Re: [LARTC] @home cable modem

[Arthur van Leeuwen]

On Tue, 3 Apr 2001, Josh Sides wrote:

> AT&T at home will provide multiple IP addresses, but they do not guarentee
> that they will be in the same subnet.  I requested two additional ip's so of
> course now I have ip's in three different subnets.
>
> With Windows I know it is only possible to have 1 active default route.
>
> Is there anyway to put all three ip's on one linux machine and have the
> internet have the ability to deliver packets to all three?

Yes. However, I do not fully understand your question. Do you want to make a
multipath uplink? Or do you just want to be reachable through all three IP
addresses? (The latter is virtually trivial).

Doei, Arthur.

-- 
  /\    / |      arthurvl@sci.kun.nl      | Work like you don't need the money
 /__\  /  | A friend is someone with whom | Love like you have never been hurt
/    \/__ | you can dare to be yourself   | Dance like there's nobody watching


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RE: [LARTC] @home cable modem

[Josh Sides]

My wording is bad.  I want to assign all ip's to one ethernet card which
will be directly connected to the cable modem.  I'm trying to set up a
situation so that I can play with iptables and nat.  I want to get rid of
the masquerading.

Thanks
Josh

On Tue, 3 Apr 2001, Josh Sides wrote:

> AT&T at home will provide multiple IP addresses, but they do not guarentee
> that they will be in the same subnet.  I requested two additional ip's so
of
> course now I have ip's in three different subnets.
>
> With Windows I know it is only possible to have 1 active default route.
>
> Is there anyway to put all three ip's on one linux machine and have the
> internet have the ability to deliver packets to all three?

Yes. However, I do not fully understand your question. Do you want to make a
multipath uplink? Or do you just want to be reachable through all three IP
addresses? (The latter is virtually trivial).

Doei, Arthur.

--
  /\    / |      arthurvl@sci.kun.nl      | Work like you don't need the
money
 /__\  /  | A friend is someone with whom | Love like you have never been
hurt
/    \/__ | you can dare to be yourself   | Dance like there's nobody
watching


_______________________________________________
LARTC mailing list / LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO:
http://ds9a.nl/2.4Routing/


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http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://ds9a.nl/2.4Routing/

RE: [LARTC] @home cable modem

[Josh Sides]

Is this as simple as adding multiple default routes?  Will it use the
default route based on the source ip?

Josh

> My wording is bad.  I want to assign all ip's to one ethernet card which
> will be directly connected to the cable modem.  I'm trying to set up a
> situation so that I can play with iptables and nat.  I want to get rid of
> the masquerading.

Thanks
Josh

On Tue, 3 Apr 2001, Josh Sides wrote:

> AT&T at home will provide multiple IP addresses, but they do not guarentee
> that they will be in the same subnet.  I requested two additional ip's so
of
> course now I have ip's in three different subnets.
>
> With Windows I know it is only possible to have 1 active default route.
>
> Is there anyway to put all three ip's on one linux machine and have the
> internet have the ability to deliver packets to all three?

Yes. However, I do not fully understand your question. Do you want to make a
multipath uplink? Or do you just want to be reachable through all three IP
addresses? (The latter is virtually trivial).

Doei, Arthur.

--
  /\    / |      arthurvl@sci.kun.nl      | Work like you don't need the
money
 /__\  /  | A friend is someone with whom | Love like you have never been
hurt
/    \/__ | you can dare to be yourself   | Dance like there's nobody
watching


_______________________________________________
LARTC mailing list / LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO:
http://ds9a.nl/2.4Routing/


_______________________________________________
LARTC mailing list / LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO:
http://ds9a.nl/2.4Routing/


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http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://ds9a.nl/2.4Routing/

RE: [LARTC] @home cable modem

[Arthur van Leeuwen]

On Tue, 3 Apr 2001, Josh Sides wrote:

> My wording is bad.  I want to assign all ip's to one ethernet card which
> will be directly connected to the cable modem.  I'm trying to set up a
> situation so that I can play with iptables and nat.  I want to get rid of
> the masquerading.

Ah. ip addr add <ipaddr1> dev eth0 && ip addr add <ipaddr2> dev eth0 && ip \
addr add <ipaddr3> dev eth0

And then you set up routes and you select which uplink IP address to use
as default. Magic needs to happen if you want to use all three.

Doei, Arthur.

-- 
  /\    / |      arthurvl@sci.kun.nl      | Work like you don't need the money
 /__\  /  | A friend is someone with whom | Love like you have never been hurt
/    \/__ | you can dare to be yourself   | Dance like there's nobody watching


_______________________________________________
LARTC mailing list / LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://ds9a.nl/2.4Routing/

RE: [LARTC] @home cable modem

[Josh Sides]

Ok.. I can do that.

How do I use all three.

I appreciate your patience and help.

Josh

-----Original Message-----
From: lartc-admin@mailman.ds9a.nl [mailto:lartc-admin@mailman.ds9a.nl]On
Behalf Of Arthur van Leeuwen
Sent: Tuesday, April 03, 2001 9:38 AM
To: Josh Sides
Cc: LARTC@mailman.ds9a.nl
Subject: RE: [LARTC] @home cable modem


On Tue, 3 Apr 2001, Josh Sides wrote:

> My wording is bad.  I want to assign all ip's to one ethernet card which
> will be directly connected to the cable modem.  I'm trying to set up a
> situation so that I can play with iptables and nat.  I want to get rid of
> the masquerading.

Ah. ip addr add <ipaddr1> dev eth0 && ip addr add <ipaddr2> dev eth0 && ip \
addr add <ipaddr3> dev eth0

And then you set up routes and you select which uplink IP address to use
as default. Magic needs to happen if you want to use all three.

Doei, Arthur.

--
  /\    / |      arthurvl@sci.kun.nl      | Work like you don't need the
money
 /__\  /  | A friend is someone with whom | Love like you have never been
hurt
/    \/__ | you can dare to be yourself   | Dance like there's nobody
watching


_______________________________________________
LARTC mailing list / LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO:
http://ds9a.nl/2.4Routing/


_______________________________________________
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http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://ds9a.nl/2.4Routing/

RE: [LARTC] @home cable modem

[Josh Sides]

I would like to put 3 different ip addresses that are in three different
subnets on the same interface.  The interface is directly connected to a
cable modem.  These ip addresses are assigned to me by my ISP.  How do I set
up the routing on my linux machine so that all three addresses are reachable
from the internet.

Is it possible to setup multiple default routes?

Thanks
Josh

-----Original Message-----
From: lartc-admin@mailman.ds9a.nl [mailto:lartc-admin@mailman.ds9a.nl]On
Behalf Of Arthur van Leeuwen
Sent: Tuesday, April 03, 2001 9:38 AM
To: Josh Sides
Cc: LARTC@mailman.ds9a.nl
Subject: RE: [LARTC] @home cable modem


On Tue, 3 Apr 2001, Josh Sides wrote:

> My wording is bad.  I want to assign all ip's to one ethernet card which
> will be directly connected to the cable modem.  I'm trying to set up a
> situation so that I can play with iptables and nat.  I want to get rid of
> the masquerading.

Ah. ip addr add <ipaddr1> dev eth0 && ip addr add <ipaddr2> dev eth0 && ip \
addr add <ipaddr3> dev eth0

And then you set up routes and you select which uplink IP address to use
as default. Magic needs to happen if you want to use all three.

Doei, Arthur.

--
  /\    / |      LARTC@mailman.ds9a.nl     | Work like you don't need the
money
 /__\  /  | A friend is someone with whom | Love like you have never been
hurt
/    \/__ | you can dare to be yourself   | Dance like there's nobody
watching


_______________________________________________
LARTC mailing list / LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO:
http://ds9a.nl/2.4Routing/


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http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://ds9a.nl/2.4Routing/

RE: [LARTC] @home cable modem

[Arthur van Leeuwen]

Sorry for not responding earlier, I've been *extremely* busy.

On Fri, 6 Apr 2001, Josh Sides wrote:

> I would like to put 3 different ip addresses that are in three different
> subnets on the same interface. The interface is directly connected to a
> cable modem.  These ip addresses are assigned to me by my ISP.  How do I set
> up the routing on my linux machine so that all three addresses are reachable
> from the internet.

The simple recipe (in pseudocode, hope this is clear enough):

0. put the ip addresses on the interfaces:

for each ip/mask:
    ip address add <ip/mask> dev <device>

1. set up the default routing table:

for each ip/mask:
    ip route add <gw_for_ip> src <ip> dev <device>

ip route add default scope global \
    nexthop via <gw_for_ip1> \
    nexthop via <gw_for_ip2> \
    nexthop via <gw_for_ip3>
    (etcetera)

2. set up policy routing tables for each of the ip addresses:

for each ip/mask:
    ip route add <ip/mask> dev <device> table <table_for_ip>
    ip route add default via <gw_for_ip> table <table_for_ip>

3. set up rules to select the correct outgoing routes

for each ip/mask:
    ip rule add from <ip/mask> table <table_for_ip> \
         prio <arbitrary unique low number>

> Is it possible to setup multiple default routes?

More or less, yes. See in the recipe. :)

Doei, Arthur.

-- 
  /\    / |      arthurvl@sci.kun.nl      | Work like you don't need the money
 /__\  /  | A friend is someone with whom | Love like you have never been hurt
/    \/__ | you can dare to be yourself   | Dance like there's nobody watching


_______________________________________________
LARTC mailing list / LARTC@mailman.ds9a.nl
http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://ds9a.nl/2.4Routing/