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fkie / multimaster_fkie

ROS stack with FKIE packages for multi-robot (discovering, synchronizing and management GUI)
BSD 3-Clause "New" or "Revised" License
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Cannot ping network computers neither discover masters #152

Open msualeh opened 3 years ago

msualeh commented 3 years ago

I am followig the procedure detailed in your technical report. My setup has eithernet based local ros networks (single ros master each) , and a computer from each local network needs to communicate over wifi to a common ros master. I am stuck with routing step "route add -net netmask 255.255.255.0 gw ", ping fails even among the local computers. I am using Ros melodic with ubuntu 18.04. Can you please suggest possible reasons for this behaviour?

atiderko commented 3 years ago

If local routing fails, the routing table appears to be faulty. But it's hard to tell what's going on without more information.

Do you try to setup the network like shown in Figure 10 of the report?

msualeh commented 3 years ago

Hello, thanks for the response. Following are the details of my system the best I can describe.

image

On 192.168.1.111 z export ROS_MASTER_URI=http:// 192.168.1.110:11311 sudo route add default gw 192.168.1.110 dev eth0 sudo sh -c "echo 0 >/proc/sys/net/ipv4/icmp_echo_ignore_broadcasts" sudo service procps restart /etc/hosts 127.0.0.1 localhost 127.0.1.1 z 192.168.1.111 z 192.168.1.110 a 192.168.0.121 lenovo

z@z:~$ ip r default via 192.168.1.110 dev eth0 default via 192.168.1.1 dev eth0 proto static metric 20100 169.254.0.0/16 dev eth0 scope link metric 1000 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.111 metric 100

z@z:~$ netstat -rn Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 0.0.0.0 192.168.1.110 0.0.0.0 UG 0 0 0 eth0 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0

On 192.168.1.110 a export ROS_MASTER_URI=http:// 192.168.1.110:11311 sudo sh -c "echo 1 >/proc/sys/net/ipv4/ip_forward" sudo service procps restart sudo route add -net 192.168.1.0 netmask 255.255.255.0 gw 192.168.0.104 sudo sh -c "echo 0 >/proc/sys/net/ipv4/icmp_echo_ignore_broadcasts" sudo service procps restart /etc/hosts 127.0.0.1 localhost 127.0.1.1 a 192.168.1.110 a 192.168.1.111 z 192.168.0.121 lenovo

a@a:~$ ip r default via 192.168.1.1 dev eth0 proto static metric 20100 default via 255.255.255.0 dev wlan0 proto static metric 20600 169.254.0.0/16 dev wlan0 scope link metric 1000 192.168.0.0/24 dev wlan0 proto kernel scope link src 192.168.0.104 metric 600 192.168.1.0/24 via 192.168.0.104 dev wlan0 scope link 192.168.1.0/24 dev eth0 proto kernel scope link src 192.168.1.110 metric 100 255.255.255.0 dev wlan0 proto static scope link metric 20600

a@a:~$ netstat -rn Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 eth0 0.0.0.0 255.255.255.0 0.0.0.0 UG 0 0 0 wlan0 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 wlan0 192.168.0.0 0.0.0.0 255.255.255.0 U 0 0 0 wlan0 192.168.1.0 192.168.0.104 255.255.255.0 UG 0 0 0 wlan0 192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 255.255.255.0 0.0.0.0 255.255.255.255 UH 0 0 0 wlan0

On 192.168.0.121 lenovo export ROS_MASTER_URI=http:// 192.168.0.121:11311 sudo sh -c "echo 0 >/proc/sys/net/ipv4/icmp_echo_ignore_broadcasts" sudo service procps restart /etc/hosts 127.0.0.1 localhost 127.0.1.1 lenovo 192.168.0.121 lenovo 192.168.1.110 a 192.168.1.111 z

Issue is that the moment I define route on default gateway. even local computers fail to ping

atiderko commented 3 years ago

sorry for delayed answer!

I think the entry sudo route add -net 192.168.1.0 netmask 255.255.255.0 gw 192.168.0.104 cause problems. Therefore, all packets to 192.168.1.111 are sent on the WLAN.

Instead you can try to enable the IP forwarding on 192.168.1.110, see e.g. https://unix.stackexchange.com/questions/449468/how-to-route-between-interfaces

msualeh commented 3 years ago

Oh, I thank and appreciate you for sparing the time to respond. I tried the solution discussed here by

  1. enable ip_forward on 192.168.x.110
  2. enter "iptables -t nat -A POSTROUTING -o wlan0 -j MASQUERADE"
  3. on 192.168.x.111 "sudo ip route add default via 192.168.x.110"
  4. on 192.168.x.111 I also set the default gateway in ethernet connection as 192.168.x.110 where, x is 1,2 and 3 in my current setup.

Now, all computers can ping 192.168.0.y and 192.168.x.110, and ros messges are being exchanged. But 192.168.x.111 can only be accessed by its own subnet's 192.168.x.110

I tried the solution discussed on the link you shared but so far I could not make it work.