Re: [Dorset] Network connectivity issues
Hi Ralph On 13/01/19 16:58, Ralph Corderoy wrote: #ip neigh add 192.168.2.8 lladdr 00:24:d2:94:35:16 dev wlp1s0 RTNETLINK answers: File exists That suggests there was an (incomplete?) entry already and either `replace' or `change' should be used. Yes, looks like something to do with arp tables, maybe tied in with clients moving from access point to access point. One access point is a router, and the others are connected to Ethernet sockets on that router. I'll do further tests. Cheers Tim -- Next meeting: BEC, Bournemouth, Tuesday, 2019-02-05 20:00 Check to whom you are replying Meetings, mailing list, IRC, ... http://dorset.lug.org.uk/ New thread, don't hijack: mailto:dorset@mailman.lug.org.uk
Re: [Dorset] Network connectivity issues
Hi Tim, > > Can Laptop SSH into Third? Ditto above WRT w(1). > > Haven't got SSH set up for SSH logins from Laptop to Third, although I > expect it to work as these machines can see each other on the network. All you really need is a TCP server that gives a known response so you can see the handshake worked and data was transferred; more work than the DHCP that succeeds. SSH transfers quite a bit back and forth before you're logged in, but a simple server can be created. $ cat >mark #! /bin/sh hostname date $ chmod +x mark Then to run it, listening on all interfaces on TCP port 12345, and running that script on every connection: $ socat tcp4-listen:12345,reuseaddr,fork exec:./mark Use your client of choice to connect, e.g. telnet(1). $ nc 127.1 12345 orac 2019-01-13 16:51:25 + Sun ^D $ $ nc 127.1 12345 orac 2019-01-13 16:52:05 + Sun ^D > OK, tried > > #ip neigh add 192.168.2.8 lladdr 00:24:d2:94:35:16 dev wlp1s0 > RTNETLINK answers: File exists That suggests there was an (incomplete?) entry already and either `replace' or `change' should be used. > So looks like a poor Wifi signal on original connect may be a factor. https://wiki.archlinux.org/index.php/Wifi says signal strength, without a GUI queering the pitch, can be seen with `iw dev interface station dump'. Perhaps there's a new source of occasional interference? Cheers, Ralph. -- Next meeting: BEC, Bournemouth, Tuesday, 2019-02-05 20:00 Check to whom you are replying Meetings, mailing list, IRC, ... http://dorset.lug.org.uk/ New thread, don't hijack: mailto:dorset@mailman.lug.org.uk
Re: [Dorset] Network connectivity issues
On 13/01/2019 14:47, t...@ls83.eclipse.co.uk wrote: Hi Ralph On 13/01/19 11:31, Ralph Corderoy wrote: Hi Tim, I'll just ask lots of questions in the hope it strikes lucky. I have a puzzling issue here, in that I can't see a laptop on my network from my own computer (normally I can ssh into the laptop just fine). Both are connected via Wifi. The laptop has a static IP. So both Computer and Laptop are *only* connected by Wi-fi. Yes. Computer's IP address is from the router's DHCP server. The Laptop's IP address is static. Is that last one done by having the DHCP server always dish out the same IP address for Laptop's MAC address, or the Laptop has it configured directly? If the latter, does the DHCP server know to steer clear of the static addresses when allocating dynamically? IP addresses are from third machine (server), which is running dhcpd dishing out addresses to Laptop and Computer. Laptop gets same IP address 192.168.2.8 from its MAC address, Computer gets its from a pool, 192.168.2.205. The DHCP server pool is well clear of the static IP's. Can Laptop see Computer, e.g. ping(1), when Computer can't see Laptop? No. All devices are on the same IP network, including the network mask? Yes. However, I can ssh into a third computer on the network How is Third connected? Also Wi-fi only? Static or dynamic IP address? Cabled, static IP 192.168.2.2. and from there can ping (and ssh into) the laptop. When Computer SSH's into Third, does w(1) show you've come from the Computer IP address you expect? Does `arp' show Computer's MAC address or that of an access point? w(1) shows 192.168.2.205 as expected. arp shows the MAC address of Computer, not an access point. Can Laptop SSH into Third? Ditto above WRT w(1). Haven't got SSH set up for SSH logins from Laptop to Third, although I expect it to work as these machines can see each other on the network. arp lists the laptop HWaddess as incomplete. There's also ip-neighbour(8) that gives `ip neigh' to show the table, and allows an entry to be added. When it's not working, you could try explicitly adding an ARP table entry to Computer for Laptop and see if that makes it work. OK, tried #ip neigh add 192.168.2.8 lladdr 00:24:d2:94:35:16 dev wlp1s0 RTNETLINK answers: File exists Further tests: Disconnecting both Computer and Laptop from the access point and then reconnecting both to a different access point. Now Computer cannot see Laptop /or/ Third computer. So disconnect Computer again and get physically close to the access point. Reconnect and now can see both. Repeat with original access point, ensuring in close proximity. Again can now see Laptop and Third from Computer. So looks like a poor Wifi signal on original connect may be a factor. I have seen something similar previously in terms of getting an IP address from the DHCP server. I appear to be connected to the network but have no IP address assigned to Computer. I am using Network Manager of XFCE and suspect that under weak Wifi conditions I'm only getting a partial connection. Cheers Tim -- Next meeting: BEC, Bournemouth, Tuesday, 2019-02-05 20:00 Check to whom you are replying Meetings, mailing list, IRC, ... http://dorset.lug.org.uk/ New thread, don't hijack: mailto:dorset@mailman.lug.org.uk I have seen with some WiFi access point the have the "the lights are on but nobody is an home" syndrome, they look like they are working (lights etc) but seemed to get stuck in a loop, you can not talk to them you can not see them they are either limited in what they do or just don't do it at all. Turn the power off to them. wait 10 seconds and then turn it back on again and everything works as normal. Is there a firmware update available for your access point? Tim H -- Next meeting: BEC, Bournemouth, Tuesday, 2019-02-05 20:00 Check to whom you are replying Meetings, mailing list, IRC, ... http://dorset.lug.org.uk/ New thread, don't hijack: mailto:dorset@mailman.lug.org.uk
Re: [Dorset] Network connectivity issues
AP isolation active ??? : https://www.linksys.com/gb/support-article?articleNum=135098 On 13/01/2019 14:47, t...@ls83.eclipse.co.uk wrote: Hi Ralph On 13/01/19 11:31, Ralph Corderoy wrote: Hi Tim, I'll just ask lots of questions in the hope it strikes lucky. I have a puzzling issue here, in that I can't see a laptop on my network from my own computer (normally I can ssh into the laptop just fine). Both are connected via Wifi. The laptop has a static IP. So both Computer and Laptop are *only* connected by Wi-fi. Yes. Computer's IP address is from the router's DHCP server. The Laptop's IP address is static. Is that last one done by having the DHCP server always dish out the same IP address for Laptop's MAC address, or the Laptop has it configured directly? If the latter, does the DHCP server know to steer clear of the static addresses when allocating dynamically? IP addresses are from third machine (server), which is running dhcpd dishing out addresses to Laptop and Computer. Laptop gets same IP address 192.168.2.8 from its MAC address, Computer gets its from a pool, 192.168.2.205. The DHCP server pool is well clear of the static IP's. Can Laptop see Computer, e.g. ping(1), when Computer can't see Laptop? No. All devices are on the same IP network, including the network mask? Yes. However, I can ssh into a third computer on the network How is Third connected? Also Wi-fi only? Static or dynamic IP address? Cabled, static IP 192.168.2.2. and from there can ping (and ssh into) the laptop. When Computer SSH's into Third, does w(1) show you've come from the Computer IP address you expect? Does `arp' show Computer's MAC address or that of an access point? w(1) shows 192.168.2.205 as expected. arp shows the MAC address of Computer, not an access point. Can Laptop SSH into Third? Ditto above WRT w(1). Haven't got SSH set up for SSH logins from Laptop to Third, although I expect it to work as these machines can see each other on the network. arp lists the laptop HWaddess as incomplete. There's also ip-neighbour(8) that gives `ip neigh' to show the table, and allows an entry to be added. When it's not working, you could try explicitly adding an ARP table entry to Computer for Laptop and see if that makes it work. OK, tried #ip neigh add 192.168.2.8 lladdr 00:24:d2:94:35:16 dev wlp1s0 RTNETLINK answers: File exists Further tests: Disconnecting both Computer and Laptop from the access point and then reconnecting both to a different access point. Now Computer cannot see Laptop /or/ Third computer. So disconnect Computer again and get physically close to the access point. Reconnect and now can see both. Repeat with original access point, ensuring in close proximity. Again can now see Laptop and Third from Computer. So looks like a poor Wifi signal on original connect may be a factor. I have seen something similar previously in terms of getting an IP address from the DHCP server. I appear to be connected to the network but have no IP address assigned to Computer. I am using Network Manager of XFCE and suspect that under weak Wifi conditions I'm only getting a partial connection. Cheers Tim -- Next meeting: BEC, Bournemouth, Tuesday, 2019-02-05 20:00 Check to whom you are replying Meetings, mailing list, IRC, ... http://dorset.lug.org.uk/ New thread, don't hijack: mailto:dorset@mailman.lug.org.uk -- Next meeting: BEC, Bournemouth, Tuesday, 2019-02-05 20:00 Check to whom you are replying Meetings, mailing list, IRC, ... http://dorset.lug.org.uk/ New thread, don't hijack: mailto:dorset@mailman.lug.org.uk
Re: [Dorset] Network connectivity issues
Hi Ralph On 13/01/19 11:31, Ralph Corderoy wrote: Hi Tim, I'll just ask lots of questions in the hope it strikes lucky. I have a puzzling issue here, in that I can't see a laptop on my network from my own computer (normally I can ssh into the laptop just fine). Both are connected via Wifi. The laptop has a static IP. So both Computer and Laptop are *only* connected by Wi-fi. Yes. Computer's IP address is from the router's DHCP server. The Laptop's IP address is static. Is that last one done by having the DHCP server always dish out the same IP address for Laptop's MAC address, or the Laptop has it configured directly? If the latter, does the DHCP server know to steer clear of the static addresses when allocating dynamically? IP addresses are from third machine (server), which is running dhcpd dishing out addresses to Laptop and Computer. Laptop gets same IP address 192.168.2.8 from its MAC address, Computer gets its from a pool, 192.168.2.205. The DHCP server pool is well clear of the static IP's. Can Laptop see Computer, e.g. ping(1), when Computer can't see Laptop? No. All devices are on the same IP network, including the network mask? Yes. However, I can ssh into a third computer on the network How is Third connected? Also Wi-fi only? Static or dynamic IP address? Cabled, static IP 192.168.2.2. and from there can ping (and ssh into) the laptop. When Computer SSH's into Third, does w(1) show you've come from the Computer IP address you expect? Does `arp' show Computer's MAC address or that of an access point? w(1) shows 192.168.2.205 as expected. arp shows the MAC address of Computer, not an access point. Can Laptop SSH into Third? Ditto above WRT w(1). Haven't got SSH set up for SSH logins from Laptop to Third, although I expect it to work as these machines can see each other on the network. arp lists the laptop HWaddess as incomplete. There's also ip-neighbour(8) that gives `ip neigh' to show the table, and allows an entry to be added. When it's not working, you could try explicitly adding an ARP table entry to Computer for Laptop and see if that makes it work. OK, tried #ip neigh add 192.168.2.8 lladdr 00:24:d2:94:35:16 dev wlp1s0 RTNETLINK answers: File exists Further tests: Disconnecting both Computer and Laptop from the access point and then reconnecting both to a different access point. Now Computer cannot see Laptop /or/ Third computer. So disconnect Computer again and get physically close to the access point. Reconnect and now can see both. Repeat with original access point, ensuring in close proximity. Again can now see Laptop and Third from Computer. So looks like a poor Wifi signal on original connect may be a factor. I have seen something similar previously in terms of getting an IP address from the DHCP server. I appear to be connected to the network but have no IP address assigned to Computer. I am using Network Manager of XFCE and suspect that under weak Wifi conditions I'm only getting a partial connection. Cheers Tim -- Next meeting: BEC, Bournemouth, Tuesday, 2019-02-05 20:00 Check to whom you are replying Meetings, mailing list, IRC, ... http://dorset.lug.org.uk/ New thread, don't hijack: mailto:dorset@mailman.lug.org.uk
Re: [Dorset] Network connectivity issues
Hi Tim, I'll just ask lots of questions in the hope it strikes lucky. > I have a puzzling issue here, in that I can't see a laptop on my > network from my own computer (normally I can ssh into the laptop just > fine). Both are connected via Wifi. The laptop has a static IP. So both Computer and Laptop are *only* connected by Wi-fi. Computer's IP address is from the router's DHCP server. The Laptop's IP address is static. Is that last one done by having the DHCP server always dish out the same IP address for Laptop's MAC address, or the Laptop has it configured directly? If the latter, does the DHCP server know to steer clear of the static addresses when allocating dynamically? Can Laptop see Computer, e.g. ping(1), when Computer can't see Laptop? All devices are on the same IP network, including the network mask? > However, I can ssh into a third computer on the network How is Third connected? Also Wi-fi only? Static or dynamic IP address? > and from there can ping (and ssh into) the laptop. When Computer SSH's into Third, does w(1) show you've come from the Computer IP address you expect? Does `arp' show Computer's MAC address or that of an access point? Can Laptop SSH into Third? Ditto above WRT w(1). > arp lists the laptop HWaddess as incomplete. There's also ip-neighbour(8) that gives `ip neigh' to show the table, and allows an entry to be added. When it's not working, you could try explicitly adding an ARP table entry to Computer for Laptop and see if that makes it work. > I am periodically seeing issues of this kind, and would like to try to > figure out what's going on. `sudo -i tcpdump -i ens35 -n arp', substituting the appropriate network interface, lets one watch ARP traffic and can be run on multiple machines at once. Cheers, Ralph. -- Next meeting: BEC, Bournemouth, Tuesday, 2019-02-05 20:00 Check to whom you are replying Meetings, mailing list, IRC, ... http://dorset.lug.org.uk/ New thread, don't hijack: mailto:dorset@mailman.lug.org.uk
Re: [Dorset] Printing from TP-Link VR400v1 router
Hi Clive, > Printer HP LJ1022 connected to USB port on rear of router (appears no > communication between units). Do you mean no Wi-fi communication, only... > Shows as connected on the TP network diagram as a HP LJ102 (think full > description too long so truncated). ... > Not found any useful info on web. Me neither. > Any suggestions please as to what to do, or cli inputs to get further > info. You could see what `open ports' the router has when accessed from the LAN, i.e. what services it is offering. `ip r' will show its IP address from your machine as the `default via...'. Here, where there is no peripherals connected to the ADSL router, I use nmap(1) with its defaults. $ sudo nmap 192.168.1.1 ... Host is up (0.0017s latency). Not shown: 994 closed ports PORT STATE SERVICE 23/tcp open telnet 53/tcp open domain 80/tcp open http 515/tcp open printer 9100/tcp open jetdirect MAC Address: D8:50:E6:B1:FB:84 (Asustek Computer) ... What's your say? Cheers, Ralph. -- Next meeting at BEC: Bournemouth, Tuesday, 2019-02-05 20:00 Check if you're replying to the list or the author Meetings, mailing list, IRC, ... http://dorset.lug.org.uk/ New thread, don't hijack: mailto:dorset@mailman.lug.org.uk
Re: [Dorset] Network connectivity issues
Hi Keith On 13/01/19 07:56, Keith Edmunds wrote: On Sat, 12 Jan 2019 19:56:35 +, t...@ls83.eclipse.co.uk said: I can't see a laptop on my network from my own computer What exact commands are you typing, and what exactly is the response? tda@ux305ca:~$ ping 192.168.2.8 PING 192.168.2.8 (192.168.2.8): 56 data bytes 92 bytes from ux305ca (192.168.2.205): Destination Host Unreachable 92 bytes from ux305ca (192.168.2.205): Destination Host Unreachable 92 bytes from ux305ca (192.168.2.205): Destination Host Unreachable -- Next meeting at BEC: Bournemouth, Tuesday, 2019-02-05 20:00 Check if you're replying to the list or the author Meetings, mailing list, IRC, ... http://dorset.lug.org.uk/ New thread, don't hijack: mailto:dorset@mailman.lug.org.uk
