Check Gateway Ping doesnt work with ECMP !

doush · Tue Aug 19, 2014 7:39 pm

Title says it all.

Router A has 192.168.1.1, 192.168.2.1, 192.168.3.1/24

Router B has 192.168.1.2, 192.168.2.2, 192.168.3.2/24

each address on different interfaces.

On Router A, 10.0.0.0/24 is routed to 192.168.1.2, 2.2 and 3.2 by ECMP and check gateway =ping.

When we disable a single address on router B like 192.168.2.2, we dont see the route unreachable on Router A and all traffic stops.

There is no NAT, no Conn Tracking.
Is this a known issue ?

Chupaka · Wed Aug 20, 2014 1:12 pm

confirming, when you add multiple gateways to a single route with 'check-gateway=ping', '/ip route nexthop print' still shows 'check-gateway=none' for those gateways

seems like the workaround is adding more routes (for any/fake destination) with each of your gateways:

ros code

/ip route
add dst-address=98.6.5.8/32 gateway=1.2.3.4,1.2.3.5
add check-gateway=ping distance=1 dst-address=192.0.0.0/24 gateway=1.2.3.4

and now we see

ros code

/ip route print detail where dst-address=98.6.5.8/32
 0 A S  dst-address=98.6.5.8/32 gateway=1.2.3.4,1.2.3.5 
        gateway-status=1.2.3.4 unreachable,1.2.3.5 reachable via  bridge1 distance=1 scope=30 target-scope=10

doush · Wed Aug 20, 2014 4:49 pm

Thanks Chupaka.

This seems like a bug.

Mikrotik team can you please confirm ?

Chupaka · Wed Aug 20, 2014 5:08 pm

please write to support@

gustavomam · Wed Oct 29, 2014 7:30 pm

Hi.

I have the same problem? Any solution for these?

I record a video you can whatch the problem

https://www.youtube.com/watch?v=Fj2kZ6T ... e=youtu.be

Chupaka · Wed Oct 29, 2014 9:49 pm

Any solution for these?

have you read my post above? starting from the words "the workaround"

doush · Mon Mar 02, 2015 7:43 pm

Hello Mikrotik Team;
Does this issue addressed and resolved ?

You are searching for bugs for the new versions but there is a major routing bug here !

Chupaka · Mon Mar 02, 2015 7:57 pm

Routing engine is rewritten for RouterOS v7, they won't do major changes in v6, so wait for first betas

doush · Sat May 30, 2015 2:14 pm

Is there any work being done about this ? It is still the same as of v6.29

Mikrotik team please tell us something.

Chupaka · Sat May 30, 2015 2:22 pm

Have you read my answers?

doush · Sat May 30, 2015 3:18 pm

Yes Chupaka thanks for your answers but I am not sure if Mikrotik is aware of the problem.

Chupaka · Mon Jun 01, 2015 4:41 pm

let's wait for v7 betas and check

Krupnik · Sat Jul 22, 2017 7:11 pm

Good day!

It is actually still, last RouterOS (6.39.2) has this issue.

But now (i tested 6.39.2) doesn't work workaround (separete route for GW). For example, I have recursive route and I expect, what when 8.8.4.4 will be unreachable, it will reflect in ECMP route. But this is not so:

[admin@MikroTik] > ip route print detail where dst-address=1.1.1.0/24
Flags: X - disabled, A - active, D - dynamic, C - connect, S - static, r - rip, b - bgp, o - ospf, m - mme, B - blackhole, U - unreachable, P - prohibit
 
 0   S  dst-address=1.1.1.0/24 gateway=8.8.4.4 gateway-status=8.8.4.4 recursive via 192.168.0.1 ether2-ISP2 check-gateway=ping distance=1 scope=30 target-scope=10
 
[admin@MikroTik] > ping 8.8.4.4
  SEQ HOST                                     SIZE TTL TIME  STATUS                                                                                                        
    0 192.168.0.1                                84  64 0ms   net unreachable                                                                                               
    1 192.168.0.1                                84  64 0ms   net unreachable                                                                                               
    sent=2 received=0 packet-loss=100%
 
 
[admin@MikroTik] > ip route print detail where dst-address=0.0.0.0/0    
Flags: X - disabled, A - active, D - dynamic, C - connect, S - static, r - rip, b - bgp, o - ospf, m - mme, B - blackhole, U - unreachable, P - prohibit
 
 0 A S  dst-address=0.0.0.0/0 gateway=8.8.4.4,8.8.8.8 gateway-status=8.8.4.4 recursive via 192.168.0.1 ether2-ISP2,8.8.8.8 recursive via 10.0.0.138 ether1-ISP1 distance=1 scope=30 target-scope=10

As we see, 8.8.4.4 unreacheble, but "ip route print detail" doesn't show "gateway-status=8.8.4.4 unreachable", it look as "gateway-status=8.8.4.4 recursive via 192.168.0.1"

Chupaka · Mon Jul 24, 2017 12:17 am

And /ip route nexthop print?

Krupnik · Mon Jul 24, 2017 12:18 pm

And /ip route nexthop print?

I will test it, thanks.

From MikroTik Team:

24.07.2017, 10:34, "Maris (MikroTik Support)":

Hello,
Any improvements and changes will be in RouterOS v7.
Best regards,
Maris

07/24/2017 11:33 - Dmitry Krupnik wrote:
Hello,
This answer i saw in forum from 2015 years. It is not "improvements", it is bug. Why do you don't fix it in v6? (thank you very mush, for release bug fix each mouth)

Tell me, please, when do you plan to release RouterOS v7?

Best regards,
Dmitry

24.07.2017, 11:36 "Maris (MikroTik Support)":
Hello,
Any routing related problem requires a lot of code rewrites, which is done only for ROS v7 because of possibility to break something else.
Maybe first beta will be released this year.
Best regards,
Maris

Very interesting position

GuJack20 · Tue Sep 10, 2019 2:04 pm

Just an update. I wanted to check if "check gateway by ping" in ECMP was fixed and I tested MikroTik RouterOS v7 beta. ECMP seems to have vanished from it's usual place. At least in first glances it is not there.

The method Chupaka described, works great though, so no reason to wait for v7 for this to be fixed