Community discussions

MikroTik App
 
kitus2
just joined
Topic Author
Posts: 4
Joined: Tue Feb 09, 2016 8:01 pm

Internal Router Traffic default interface

Sun Jul 24, 2016 12:29 am

I've been trying to find the native IP/interface used when generating own router traffic, such as package upgrades, but I have been unable to find it. I am sure it must be a trivial setting, that I've must have come across multiple times without noticing, but I can't find it.

The scenario, is as follows:

One wireless IP address, ie 10.20.30.2, internal, not routable to the outside (at some point that network is not backwards routable, by design), one internal IP address in the ethernet port, ie 192.168.10.2, that routes traffic correctly (actually local clients work great).
As the router attempts to do a PING to anywhere, it will get no response, if you don't select manually the originating ip as the local ethernet one. When trying to update the packages, it will not resolve the DNS host, neither find the update server (obviously, as it is generating traffic from the 10.20.30.2).

The only way I've found to reliable solve this issue, is by reinstalling the configuration, and setting the ethernet address first.

Thanks in advance!
 
cutedrummerboy
Member Candidate
Member Candidate
Posts: 137
Joined: Thu Nov 14, 2013 6:32 pm

Re: Internal Router Traffic default interface

Sun Jul 24, 2016 6:45 am

make a bridge and assign an ip to it. now it will be reachable via any interface of your router.


edit: set the default gateway in your router.
Device: RB2011UIAS-RM, RB750GL, CISCO SG300-28, UNIFI UAP-LR
 
pe1chl
Forum Guru
Forum Guru
Posts: 6675
Joined: Mon Jun 08, 2015 12:09 pm

Re: Internal Router Traffic default interface

Tue Jul 26, 2016 8:21 pm

"I've been trying to find the native IP/interface used when generating own router traffic, such as package upgrades, but I have been unable to find it."

That is because (I think) it does not exist.   What Linux normally does: the route to the destination of the packet is looked up, and when a match
is found (usually via the default gateway in cases like this), the address assigned to the interface where the packet would leave is selected as the
source address.  When there is no route, I think it will get the address of the lowest numbered interface (roughly equivalent to the first interface
that was brought up).   That appears to be consistent with what you find.
 
kitus2
just joined
Topic Author
Posts: 4
Joined: Tue Feb 09, 2016 8:01 pm

Re: Internal Router Traffic default interface

Wed Aug 10, 2016 8:24 pm

That is consistent with the results found.

I think that RouterOS should allow to renumerate the ID, if this is supposed to be a routing software...

In the meanwhile, If the default route is populated with the desired source interface, the router can get through the connection and access the outside world.

Thanks a lot for your clarifying reply.

Who is online

Users browsing this forum: samnang340 and 129 guests