freebsd-questions Digest, Vol 634, Issue 2

[Manish Jain]

On Tue, Jul 26, 2016 at 5:30 PM, freebsd-questions-***@freebsd.org wrote:
Try mtr instead of ping (in ports) -- it shows you /where/ the packets are being lost. 'netstat -i' is also a good thing to check. If there are any packet errors, particularly if they are going up over time, then there's a physical problem somewhere on your local network. Frequently this is due to bad ethernet cables, but it could be some more expensive bit of hardware going wonky. Also, you need to do: service netif restart && service routing restart to completely refresh your network interfaces. Not restarting the routing explains at least part of what you're seeing. This sort of problem is almost never down to malfeasance -- the black hats would typically rather have control over your fully working hardware and will frequently try and avoid doing anything that would lead to being discovered. Most likely it's a software configuration problem, or failing that, hardware failure.

Thanks a lot for such a detailed response. I will try it whenever I lose network again. If it's an issue with software configuration, I will update it here.

One of the great things about freebsd is the amount of plain-spoken advice available at this list. Thanks again
Manish Jain

[Manish Jain]

On Tue, Jul 26, 2016 at 6:40 PM, Manish Jain <***@hotmail.com> wrote:
Try mtr instead of ping (in ports) -- it shows you /where/ the packets are being lost. 'netstat -i' is also a good thing to check. If there are any packet errors, particularly if they are going up over time, then there's a physical problem somewhere on your local network. Frequently this is due to bad ethernet cables, but it could be some more expensive bit of hardware going wonky. Also, you need to do: service netif restart && service routing restart to completely refresh your network interfaces. Not restarting the routing explains at least part of what you're seeing. This sort of problem is almost never down to malfeasance -- the black hats would typically rather have control over your fully working hardware and will frequently try and avoid doing anything that would lead to being discovered. Most likely it's a software configuration problem, or failing that, hardware failure.


I just happened to have a network loss. 'mtr www.freebsd.org' comes up with an empty window (unlike previously when the mtr window listed many hosts on the route)

Running 'netstat -i' twice at an interval of about 1 minute produced the following :

/usr/home/bourne # date && echo && netstat -i
Tue 26 Jul 2016 19:08:12 IST

Name Mtu Network Address Ipkts Ierrs Idrop Opkts Oerrs Coll
re0 1500 <Link#1> 50:46:5d:66:fd:10 13894 0 0 11581 0 0
re0 - 192.168.1.0 192.168.1.3 13639 - - 11568 - -
re0 - fe80::5246:5d fe80::5246:5dff:f 0 - - 5 - -
lo0 16384 <Link#2> 698 0 0 698 0 0
lo0 - localhost ::1 348 - - 348 - -
lo0 - fe80::1%lo0 fe80::1%lo0 0 - - 0 - -
lo0 - your-net localhost 350 - - 350 - -

/usr/home/bourne # date && echo && netstat -i
Tue 26 Jul 2016 19:09:22 IST

Name Mtu Network Address Ipkts Ierrs Idrop Opkts Oerrs Coll
re0 1500 <Link#1> 50:46:5d:66:fd:10 13983 0 0 11655 0 0
re0 - 192.168.1.0 192.168.1.3 13726 - - 11642 - -
re0 - fe80::5246:5d fe80::5246:5dff:f 0 - - 5 - -
lo0 16384 <Link#2> 866 0 0 866 0 0
lo0 - localhost ::1 432 - - 432 - -
lo0 - fe80::1%lo0 fe80::1%lo0 0 - - 0 - -
lo0 - your-net localhost 434 - - 434 - -

Then I ran (as root):
service netif restart
service routing restart

At this point, I get my network back : - )

What would this mean ? Is this a software problem, or some of my hardware has started failing ?

If you could kindly include my email address ***@hotmail.com in the cc list, I will be able to spot your reply more easily.

Thanks for your help
Manish Jain

[Manish Jain]

On Tue, Jul 26, 2016 at 7:20 PM, Manish Jain <***@hotmail.com> wrote:
I just happened to have a network loss. 'mtr www.freebsd.org' comes up with an empty window (unlike previously when the mtr window listed many hosts on the route)

Running 'netstat -i' twice at an interval of about 1 minute produced the following :

/usr/home/bourne # date && echo && netstat -i
Tue 26 Jul 2016 19:08:12 IST

Name Mtu Network Address Ipkts Ierrs Idrop Opkts Oerrs Coll
re0 1500 <Link#1> 50:46:5d:66:fd:10 13894 0 0 11581 0 0
re0 - 192.168.1.0 192.168.1.3 13639 - - 11568 - -
re0 - fe80::5246:5d fe80::5246:5dff:f 0 - - 5 - -
lo0 16384 <Link#2> 698 0 0 698 0 0
lo0 - localhost ::1 348 - - 348 - -
lo0 - fe80::1%lo0 fe80::1%lo0 0 - - 0 - -
lo0 - your-net localhost 350 - - 350 - -

/usr/home/bourne # date && echo && netstat -i
Tue 26 Jul 2016 19:09:22 IST

Name Mtu Network Address Ipkts Ierrs Idrop Opkts Oerrs Coll
re0 1500 <Link#1> 50:46:5d:66:fd:10 13983 0 0 11655 0 0
re0 - 192.168.1.0 192.168.1.3 13726 - - 11642 - -
re0 - fe80::5246:5d fe80::5246:5dff:f 0 - - 5 - -
lo0 16384 <Link#2> 866 0 0 866 0 0
lo0 - localhost ::1 432 - - 432 - -
lo0 - fe80::1%lo0 fe80::1%lo0 0 - - 0 - -
lo0 - your-net localhost 434 - - 434 - -

Then I ran (as root):
service netif restart
service routing restart

At this point, I get my network back : - )

I was a bit hasty in sending the previous update. There was another outage a few moments back, and restarting netif/routing did not help. Rebooting the system did.

'service routing restart' produces the following output :

/root <<: service routing restart
route: writing to routing socket: No such process
delete net default: gateway 192.168.1.1 fib 0: not in table
delete net fe80::: gateway ::1
delete net ff02::: gateway ::1
delete net ::ffff:0.0.0.0: gateway ::1
delete net ::0.0.0.0: gateway ::1
add net default: gateway 192.168.1.1
add net fe80::: gateway ::1
add net ff02::: gateway ::1
add net ::ffff:0.0.0.0: gateway ::1
add net ::0.0.0.0: gateway ::1

Is this okay, or is there some problem you can spot ?

Thanks for any further help
Manish Jain
***@hotmail.com

[Lowell Gilbert]

Post by Manish Jain
service netif restart
service routing restart
At this point, I get my network back : - )
What would this mean ? Is this a software problem, or some of my hardware has started failing ?

Have you tried rebooting whatever device is on the other end of the
cable plugged into re0? Switch, router, whatever...