CentOS - Dec 2015 - routing with 2 public ips

This is half true.
Depends on the application or the way that the network traffic is 
flowing you could use some iptables rules to mark a connection for 
example by the source MAC address per new connections which would be a 
specific router and by that mark the connection, then in the routing 
level decide which default gateway to use for this specific connection.
You can take a look at an example that I wrote and modify it to use a 
MAC address match instead of NFQUEUE at:
http://wiki.squid-cache.org/EliezerCroitoru/Drafts/MwanLB#iptables_rules_example

The idea is that you mark a new connection from a specific router with a 
unique mark and then restore the connection mark to force a specific 
routing table on this mark(IE connection)

Hope it Helps,
Eliezer

On 25/12/2015 22:28, Paul R. Ganci wrote:
> On 12/25/2015 12:44 PM, Joey wrote:
>>
>> i have a server with 2 public ips on 2 devices.
>>
>> I want that the request of incoming traffic dont use the default
>> gateway. Incoming traffic sould be answered using the gateway of the
>> incoming device
>>
>> Could i realize this with firewalld? Or directly iptables?
>
> No you can not do that via firewalld or iptables. The problem is you
> have to tell the packets to go out the proper interface which must be
> done via routing tables. For that purpose you need ip route. I suggest
> you take a look at
>
>
https://kindlund.wordpress.com/2007/11/19/configuring-multiple-default-routes-in-linux/
>
>
> This link provides a very thorough description of what must be done.
>
> Just a warning is that you will want your routing tables to be
> maintained across system boots. I put my routes for my bridged
> interfaces into:
>
> /etc/sysconfig/network-scripts/route-br1
> /etc/sysconfig/network-scripts/route-br2
>
> You can put your routes into similar files... just replace the br1/br2
> with your appropriate interface names.
>

On 12/26/2015 08:16 PM, Eliezer Croitoru wrote:
> you could use some iptables rules to mark a connection for example by 
> the source MAC address per new connections which would be a specific 
> router and by that mark the connection, then in the routing level 
> decide which default gateway to use for this specific connection. 
While that's true, you still have to select the default route using "ip
rule".  And since you can do that using the source address for outgoing 
packets, there's no reason to mark them.  It's completely redundant.

On 27/12/2015 22:49, Gordon Messmer wrote:
> While that's true, you still have to select the default route using
"ip
> rule".  And since you can do that using the source address for
outgoing
> packets, there's no reason to mark them.  It's completely
redundant.
Can you match the MAC address?? in ip rule?
If so it's much simpler then I was estimating.

Eliezer