Community discussions

MikroTik App
  4. RouterOS
  5. General

No ethernet link: how to debug?

Post Reply
 
el berto
Member Candidate
Member Candidate
Topic Author
Posts: 223
Joined: Wed Sep 26, 2007 10:53 am

No ethernet link: how to debug?

Wed May 31, 2017 4:25 pm

I have several routerboards connected to same ethernet switch.
Routerboard are all powered, led switches are on but often I can't ping devices.

Code: Select all
    sent=200 received=144 packet-loss=28% min-rtt=1ms avg-rtt=3ms 
   max-rtt=21ms 
HOST                                     SIZE TTL TIME  STATUS                 
192.168.81.2                               56  63 1ms  
192.168.81.2                               56  63 1ms  
192.168.81.2                               56  63 1ms  
192.168.81.2                               56  63 1ms  
192.168.81.2                               56  63 1ms  
192.168.81.2                               56  63 1ms  
192.168.81.2                               56  63 1ms  
192.168.81.2                               56  63 1ms  
192.168.81.2                               56  63 1ms  
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                               56  63 1ms  
192.168.81.2                               56  63 1ms  
192.168.81.2                               56  63 2ms  
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
    sent=220 received=156 packet-loss=29% min-rtt=1ms avg-rtt=3ms 
   max-rtt=21ms 
HOST                                     SIZE TTL TIME  STATUS                 
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                                            timeout                
192.168.81.2                               56  63 1ms  
192.168.81.2                               56  63 1ms  
192.168.81.2                               56  63 1ms  
192.168.81.2                               56  63 1ms  
192.168.81.2                               56  63 1ms  
192.168.81.2                               56  63 1ms

For debugging purposes I use netwatch:

Code: Select all
10:19:53 script,info 192.168.83.13 down 
10:20:00 script,info 192.168.83.13 up 
10:21:13 script,info 192.168.83.13 down 
10:21:20 script,info 192.168.83.13 up 
10:22:03 script,info 192.168.83.13 down 
10:22:10 script,info 192.168.83.13 up 
10:24:53 script,info 192.168.83.13 down
In these examples I'm using different IP as example.

Is there a way to debug (using system log messages) to understand what's happening?
Thanks.
Top
 
User avatar
AlainCasault
Trainer
Trainer
Posts: 632
Joined: Fri Apr 30, 2010 3:25 pm
Location: Prévost, QC, Canada
Contact:
Contact AlainCasault

Re: No ethernet link: how to debug?

Wed May 31, 2017 4:42 pm

Hello

If you have the same problem with all RBs, start by replacing the switch. If it's only certain routers, swap cabling.

Start with the simple causes before looking for the hard ones ;)




Sent from Tapatalk
Top
 
el berto
Member Candidate
Member Candidate
Topic Author
Posts: 223
Joined: Wed Sep 26, 2007 10:53 am

Re: No ethernet link: how to debug?

Wed May 31, 2017 8:58 pm

I set same netwatch on other RBs so I discovered I have same trouble on different subnets; tomorrow I'll try but I suppose I can't have 3 switches broken at same time....
Top
 
User avatar
AlainCasault
Trainer
Trainer
Posts: 632
Joined: Fri Apr 30, 2010 3:25 pm
Location: Prévost, QC, Canada
Contact:
Contact AlainCasault

Re: No ethernet link: how to debug?

Wed May 31, 2017 10:08 pm

Then you should describe your setup with more precision. Originally, you only spoke of one switch.

Regards,

Sent from Tapatalk
Top
 
jarda
Forum Guru
Forum Guru
Posts: 7756
Joined: Mon Oct 22, 2012 4:46 pm

Re: No ethernet link: how to debug?

Thu Jun 01, 2017 8:53 am

If you have stp or rstp on, disable it.
Top
 
el berto
Member Candidate
Member Candidate
Topic Author
Posts: 223
Joined: Wed Sep 26, 2007 10:53 am

Re: No ethernet link: how to debug?

Thu Jun 01, 2017 10:26 am

I have RSTP on to prevent issues when closing wireless ring, but actually I enable/disable manually the ring. That's to have a "main" ling to remote station using intermediate repeater; if main link fails I switch to backup but it can happen I have both wireless links active.
Even with RTSP on it has correctly worked for years.
It seems strange I suddenly have same trouble on different networks....
I'll draw schematic and I'll post.
Top
 
jarda
Forum Guru
Forum Guru
Posts: 7756
Joined: Mon Oct 22, 2012 4:46 pm

Re: No ethernet link: how to debug?

Thu Jun 01, 2017 10:29 am

Maybe you have mixed older and newer ros versions. They have incompatible rstp implementations... Or the problem could be elsewhere of course...
Top
 
el berto
Member Candidate
Member Candidate
Topic Author
Posts: 223
Joined: Wed Sep 26, 2007 10:53 am

Re: No ethernet link: how to debug?

Thu Jun 01, 2017 10:49 am

Most of my RB has got version 6.19, is it incompatible with newer versions? (or older ones?)
Mmh... are there differences between RSTP of 6.19 and 6.30.4 or 6.36.3?
Top
 
User avatar
AlainCasault
Trainer
Trainer
Posts: 632
Joined: Fri Apr 30, 2010 3:25 pm
Location: Prévost, QC, Canada
Contact:
Contact AlainCasault

Re: No ethernet link: how to debug?

Thu Jun 01, 2017 9:16 pm

If you disable (r)stp, make sure you have no layer one loops. Then you'll bring your network down real fast! ;)

Sent from Tapatalk
Top
 
jarda
Forum Guru
Forum Guru
Posts: 7756
Joined: Mon Oct 22, 2012 4:46 pm

Re: No ethernet link: how to debug?

Fri Jun 02, 2017 11:18 am

https://mikrotik.com/download/changelog ... lease-tree

6.38 was the point of change.
Top
Post Reply

Who is online

Users browsing this forum: Bing [Bot], Dobby55, glushkoo, jaclaz, reman6110 and 131 guests
  4. RouterOS
  5. General