* Re: [LARTC] Aliases and Multipath
2003-12-04 15:06 [LARTC] Aliases and Multipath Guillermo Gomez
@ 2003-12-05 14:03 ` Guillermo Gomez
2003-12-08 0:37 ` Damion de Soto
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Guillermo Gomez @ 2003-12-05 14:03 UTC (permalink / raw)
To: lartc
Thanks guys for such quick response :) coool
Well let me go deeper now with my routing issuess.
My desirable topology is:
LAN ---- Linux Box ---- eth0 -- dsl router (dhcp)
eth0:1 -- Frame Router ISP1 (fixed ip range)
eth0:2 -- Frame Router ISP2 (fixed ip range)
Then i would config:
eth0 according dhcp server aa.aa.aa.aa
eth0:1 xx.xx.xx.xx
eth0:2 yy.yy.yy.yy
The idea is to balance the outgoing traffic through the three ISPs. One
little trouble is dhcp renewal (it always tries to set the default
gateway, anyone knows how to avoid that? i could find out from
dhcp-client-leases and then configure myself at the right place at the
right moment).
According to the FAQ i need to guarantee first that any request from
eth0 IPADDR goes to the right gateway and so on with eth0:1 and eth0:2
(that's reasonable).
After that i would do the multipath config. The question goes now with
the NAT stuff, how can i do the SNAT after balancing the traffic with
the multipath routing? I can't do:
iptables -t nat -A POSTROUTING -o eth0 -j SNAT aa.aa.aa.aa
iptables -t nat -A POSTROUTING -o eth0:1 -j SNAT xx.xx.xx.xx
iptables -t nat -A POSTROUTING -o eth0:2 -j SNAT yy.yy.yy.yy
iptables just does not likes eth0:1 neither eth0:2, is this the right
behaviour of iptables or what? i read something about NAT in advance
routing engine but never used before and i'm little confuse on how it
works. Will it crash with iptables NAT engine?
Just to finish to build the router i need to do DNAT for my internal
servers but that's trivial with iptables but anyway it would be great to
know how to do it with a single tool (don't need to do firewalling in
this machine so far, just routing and stateless nat, our should it be
statefull? hmmmm need to think about).
Heeey, does anyone knows if someone has translated the LARTC-FAQs to
Spanish? I could do that :) I would like to contribute...
Kind regards
Guillermo
--
Guillermo Gomez <ggomez@neotechgw.net>
neotech
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [LARTC] Aliases and Multipath
2003-12-04 15:06 [LARTC] Aliases and Multipath Guillermo Gomez
2003-12-05 14:03 ` Guillermo Gomez
@ 2003-12-08 0:37 ` Damion de Soto
2003-12-08 11:34 ` Guillermo Gomez
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Damion de Soto @ 2003-12-08 0:37 UTC (permalink / raw)
To: lartc
Hi Guillermo,
> iptables just does not likes eth0:1 neither eth0:2, is this the right
> behaviour of iptables or what? i read something about NAT in advance
> routing engine but never used before and i'm little confuse on how it
> works. Will it crash with iptables NAT engine?
As far as I know, the ethX:X terminology is just for ifconfig usage.
Inside the kernel, eth0:1 is exactly the same as eth0.
So for iptables rules, you just use the eth0:1 IP address with eth0.
this is the same way the 'ip' tool works too.
Regards,
Damion.
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Damion de Soto - Software Engineer email: damion@snapgear.com
SnapGear - A CyberGuard Company --- ph: +61 7 3435 2809
| Custom Embedded Solutions fax: +61 7 3891 3630
| and Security Appliances web: http://www.snapgear.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--- Free Embedded Linux Distro at http://www.snapgear.org ---
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [LARTC] Aliases and Multipath
2003-12-04 15:06 [LARTC] Aliases and Multipath Guillermo Gomez
2003-12-05 14:03 ` Guillermo Gomez
2003-12-08 0:37 ` Damion de Soto
@ 2003-12-08 11:34 ` Guillermo Gomez
2003-12-08 12:35 ` Jose Luis Domingo Lopez
2003-12-10 4:12 ` Damion de Soto
4 siblings, 0 replies; 6+ messages in thread
From: Guillermo Gomez @ 2003-12-08 11:34 UTC (permalink / raw)
To: lartc
Got it, thanks Damion
It was so easy to think in using directly ethx:y in iptables :(
Anyway,my point is that i need to do SNAT in a three ISP environment
with multipath routing to balance the outgoing traffic.
So far i decided to go with separate Ethernet cards so i will go back to
the aliasing thing later.
Now i will do NAT with iptables in separate cards in POSTROUTING chain
(after routing decision has taken).
By the way, what's the behaviour of multipath routing if one of the
providers goes down ? Should i take care manually to take it out from
the multipath ?
Guillermo
On Sun, 2003-12-07 at 20:37, Damion de Soto wrote:
> Hi Guillermo,
>
> > iptables just does not likes eth0:1 neither eth0:2, is this the right
> > behaviour of iptables or what? i read something about NAT in advance
> > routing engine but never used before and i'm little confuse on how it
> > works. Will it crash with iptables NAT engine?
> As far as I know, the ethX:X terminology is just for ifconfig usage.
> Inside the kernel, eth0:1 is exactly the same as eth0.
> So for iptables rules, you just use the eth0:1 IP address with eth0.
> this is the same way the 'ip' tool works too.
>
>
> Regards,
> Damion.
>
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [LARTC] Aliases and Multipath
2003-12-04 15:06 [LARTC] Aliases and Multipath Guillermo Gomez
` (2 preceding siblings ...)
2003-12-08 11:34 ` Guillermo Gomez
@ 2003-12-08 12:35 ` Jose Luis Domingo Lopez
2003-12-10 4:12 ` Damion de Soto
4 siblings, 0 replies; 6+ messages in thread
From: Jose Luis Domingo Lopez @ 2003-12-08 12:35 UTC (permalink / raw)
To: lartc
On Thursday, 04 December 2003, at 11:06:58 -0400,
Guillermo Gomez wrote:
> Does anyone know if i can use ethernet aliases like eth0:1 in advanced
> routing like multipath routing in order to avoid to have nxEthernet
> interfaces in my Linux box.
>
I think it is always better to think "in ip terms" instead of "in
ifconfig terms" with respect to multiple IP addresses assigned to the
same network interface.
I don't know exactly for "ifconfig", but the syntax for "ip address"
states clearly what seems to be happening behind the scenes:
# ip address add 172.16.1.1/24 broad + dev eth1
# ip address add 172.16.2.1/24 broad + dev eth1
# ip address add 172.16.3.1/24 broad + dev eth1
So what you are doing is assigning several IP to the same physical
interface, and you deal just with IP, anything else.
# ip address show dev eth1
2: eth1: <BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast qlen 1000
link/ether 00:05:1c:09:f2:14 brd ff:ff:ff:ff:ff:ff
inet 192.168.1.12/24 brd 192.168.1.255 scope global eth0
inet 172.16.1.1/24 brd 172.16.1.255 scope global eth0
inet 172.16.2.1/24 brd 172.16.2.255 scope global eth0
inet 172.16.3.1/24 brd 172.16.3.255 scope global eth0
Greetings.
--
Jose Luis Domingo Lopez
Linux Registered User #189436 Debian Linux Sid (Linux 2.6.0-test10-mm1)
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^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [LARTC] Aliases and Multipath
2003-12-04 15:06 [LARTC] Aliases and Multipath Guillermo Gomez
` (3 preceding siblings ...)
2003-12-08 12:35 ` Jose Luis Domingo Lopez
@ 2003-12-10 4:12 ` Damion de Soto
4 siblings, 0 replies; 6+ messages in thread
From: Damion de Soto @ 2003-12-10 4:12 UTC (permalink / raw)
To: lartc
Guillermo Gomez wrote:
> By the way, what's the behaviour of multipath routing if one of the
> providers goes down ? Should i take care manually to take it out from
> the multipath ?
I think it will still try to be routed out the link that is down.
The linux kernel only removes routes if the actual eth device goes down.
You'll need some way of determining which links are down and removing the routes.
have you read:
http://www.ssi.bg/~ja/nano.txt
You probabaly don't want to use all of that, but some parts will be suitable.
Regards,
--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Damion de Soto - Software Engineer email: damion@snapgear.com
SnapGear - A CyberGuard Company --- ph: +61 7 3435 2809
| Custom Embedded Solutions fax: +61 7 3891 3630
| and Security Appliances web: http://www.snapgear.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
--- Free Embedded Linux Distro at http://www.snapgear.org ---
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http://mailman.ds9a.nl/mailman/listinfo/lartc HOWTO: http://lartc.org/
^ permalink raw reply [flat|nested] 6+ messages in thread