** Tim <t...@xendistar.co.uk> [2019-01-13 16:39]: > 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. > > 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? ** end quote [Tim]
I see that sometimes with my access point. It seems to pass traffic fine on the wired connections, and several existing wireless connections work fine, but new ones and the odd existing one and indicate they are working, but completely fail when it comes to actually using anything on the network. After a while they stop picking up DHCP leases (likely beause my AP doesn't handle that as my config is beyond its capabilities - or was historically). After a while (if I leave it that long) other devices start failing to route traffic too. I have found the same issue with my the Billion BiPAC 7800N, the replacement Netgear WNDR3700, the next replacement TP-Link TL-WDR3600 and the current Netgear WNDR3700 with OpenWRT installed (which is actually much better, but still not perfect). The Netgear was aimed at improving performance, but was replaced because there were two features on it that I needed that couldn't be used at the same time (from memory VPN and IPv6). The TP-Link was replaced because it seems that it doesn't support IPv6 with the majority of ISPs in the UK (hard coded a /64 when most supply a /56). I'm still working on IPv6 on OpenWRT. I've got a tunnel with Hurricane Electric working, but not my native addresses from my ISP (I must have a decent conversation with them to confirm their setup). Comparing to the old Billion isn't helpful because that just had a tick box to enable IPv6 which 'just worked'! Anyhoo, I've strayed off the original thread! -- Paul Tansom | Aptanet Ltd. | https://www.aptanet.com/ | 023 9238 0001 Vice Chair, FSB Portsmouth & SE Hampshire Branch | http://www.fsb.org.uk/ ============================================================================= Registered in England | Company No: 4905028 | Registered Office: Ralls House, Parklands Business Park, Forrest Road, Denmead, Waterlooville, Hants, PO7 6XP -- 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
