scripts work fine, if there's one static default route entry

RouterOS General
1

(There is a diagram below)

This whole problem is centered around, what I call ROUTER A, and services which connect to the internet running on ROUTER A (like DNS, like /tool fetch, etc)

I have a router with 3 default routes, advertised by ospf only
but none of those default routes are static in the table with a lower (direct) cost. they all are calculated via ospf.
connected/adjacent routes can use these routes to get to the internet
however, if you use a local utility to connect, it wont work until you add a static default gateway entry.

okay, before you say I’m crazy.

  • I can ping from this router (A)
  • I can go on and adjacent network, and ping to the internet
  • ospf works fine

however, I have some timed scripts which run, and use /tool fetch http to get/post to web services.

those items fail.. and fail miserably.. they actually just lock up, and dont go anywhere.

okay.

So, now, if I add a default static route (0.0.0.0 via ether1) – by example, on Router A.

The script stops locking up, and runs, however, now, that script wont use the ECMP benefits of OSPF.

And – even worse, all traffic passing through the router, will now only go out that static default lower cost route.

I’ve even tried raising the cost of the static default route, higher than OSPF, it still is the chosen route for the /tool fetch scripts, and all other adjacent-originated traffic.

Why!?

How can I fix this?

– Pepin

Below is a diagram of my network:

   (GW-0)            (GW1)                  (GW2)
0.0.0.0 - \    0.0.0.0 - \         0.0.0.0 - \
  (ROUTER B)      (ROUTER C)          (ROUTER D)
     \ (OSPF)           \  (OSPF)              \  (OSPF)
172.16.0.0/30       172.16.0.4/30          172.16.0.8/30 
         \                     \                      \
        [ ROUTER A --------[OSPF enabled]----------------------- ]
                /                         \                \  
    192.168.77.0/24          192.168.78.0/24         192.168.79.0/24
    (public users)                (private #1)                 (private #2)
2

I would guess that it has to do with what IP the script is sourcing from. Is it possible that the script is using a private IP that you are not masquerading? You could NAT any traffic with a src ip of that router from your gateway if this is the issue.

3

That is a good idea bro. I never really considered that maybe the script is trying to fetch as 127.0.0.1 or something of the like.

I will try this out and let you know.

Thumbs Up to you!

– Pepin