I have tried connecting the router directly to my laptop and it seems to work fine, but I can’t leave it plugged in this way. I then tried various different ports on the switch, and they all seem to have similar problems.
I have some servers connected with static IP’s and they can ping the router OK, but my laptop is currently having some issues:
$ ping 10.0.2.200
PING 10.0.2.200 (10.0.2.200): 56 data bytes
Request timeout for icmp_seq 0
Request timeout for icmp_seq 1
Request timeout for icmp_seq 2
Request timeout for icmp_seq 3
Request timeout for icmp_seq 4
Request timeout for icmp_seq 5
64 bytes from 10.0.2.200: icmp_seq=6 ttl=64 time=3.562 ms
64 bytes from 10.0.2.200: icmp_seq=7 ttl=64 time=1.109 ms
64 bytes from 10.0.2.200: icmp_seq=8 ttl=64 time=3.459 ms
64 bytes from 10.0.2.200: icmp_seq=9 ttl=64 time=3.208 ms
64 bytes from 10.0.2.200: icmp_seq=10 ttl=64 time=3.542 ms
64 bytes from 10.0.2.200: icmp_seq=11 ttl=64 time=5.329 ms
64 bytes from 10.0.2.200: icmp_seq=12 ttl=64 time=3.649 ms
64 bytes from 10.0.2.200: icmp_seq=13 ttl=64 time=3.956 ms
How can I debug this network error?
Are you using a managed switch or unmanaged switch. If your computer works when coonnected directly to router then there is a problem with the switch and you either should reset config if it managed and redo. Or if it unamanged I would replace the switch.
It’s a unmanaged switch (Netgear JGS524). I have no issues with any other devices on this switch and it is the main hub of our network. I have tried moving the RB2011 to different ports (4, 8, 21, 22) and each time it works fine for a while, and then becomes unresponsive.
I have been running the DHCP server on the original router and getting my IP address from this router at 10.0.2.1. What is strange is that I can then ping the RB2011 without any issues. However if I set static IP settings like this:
IP Address: 10.0.2.222
Network: 10.0.2.0/24
Subnet: 255.255.255.0
Gateway: 10.0.2.200
then I can’t ping the RB2011. Unless I unplug it from the switch and plug it in another port which refreshes things. It’s hard to determine whether it is the switch at fault as whenever I replug the RB2011 it always works for a while and it’s hard to know when it fails as I have left the office by then. I can’t leave my laptop connected for a week!
EDIT: I changed the subnet to 255.255.255.255 and I could instantly ping the RB2011 when my gateway is set to this router and I can access the internet. However I can’t access any devices on LAN. So there seems to be an issue with using the 255.255.255.0 subnet mask.
Why is this?
After being able to ping the RB2011 this morning, I could suddenly no longer ping it when connected to the other router. I thought the issue could be with the port on the RB2011 instead of the switch so I just unplugged the cable from ether5 and plugged it into ether6 and the RB2011 was instantly available again. There is obviously something wrong though as I fully expect this to time out at some point, probably in a day or two.
Another curious thing I have noticed is that I can login to another machine which is connected to both the old router and the RB2011 and from there I can ping the RB2011. So the connection appears to be fine for that machine.
The issue seems to be other devices making a connection and maintaining it. Surely this rules out a faulty port on the switch?
Is it possible you’re getting an IP address conflict?
The only DHCP server running is on the old router and is assigning addresses in the range 10.0.2.100-199
The RB2011 is set to use the address 10.0.2.200, so there should be no other devices using that address. I have just unplugged the RB2011 from the network and tried pinging it from a server that previously had no issue connecting to it and it now (unsurprisingly) can’t see it. There is no response at all, which I take to mean that there is no other device using that address…
Another thing to check is that you are not having a mac address conflict. For instance if you backup a config from one router and pasted on the other they will have same mac addresses on corresponding ports. worth checking.