[Dnsmasq-discuss] DHCP problem when moving from one WiFi SSID to another
I have a large[ish[ house and to provide good WiFi throughout I run two Draytek routers. The 'main' one is a Vigor 2860n which connects to the internet by FTTC, the second one is an old Vigor 2820n which has its WAN disabled and the LAN hardwired to the 2860n LAN. Currently I'm using the same SSID on both routers, I've read quite a lot around this and the weight of opinion seems to be that using the same SSID should work OK and is more transparent to the user than using different ones. However I have also tried different SSIDs for the two routers requiring user intervention to move from one to the other, this shows the same symptoms (described below) as using the same SSID. What happens is that when I move around such that the WiFi connection should move from the 2820n to the 2860n my laptop loses its IP address. DHCP and DNS is provided by dnsmasq running on a RaspberryPi, the basic IPV4 setup is as follows:- Vigor 2860n - 192.168.1.1 Raspberry Pi - 192.168.1.2 (runs dnsmasq) Desktop 192.168.1.3 Vigor 2820n - 192.168.1.20 The Pi assigns IP addresses from 192.168.80 to 192.168.1.127 and the conf file is:- domain-needed bogus-priv expand-hosts domain=zbmc.eu dhcp-range=192.168.1.80,192.168.1.127,12h dhcp-option=3,192.168.1.1 local=/zbmc.eu/ cname=bbb,beaglebone cname=mx201,maxine-X201 cname=ben,DESKTOP-978VD5M cname=oki,MC342-AE529C dhcp-host=00:BB:3A:E9:A3:15,maxineKindle dhcp-host=00:09:B0:C9:CE:81,onkyoTx-nr616 dhcp-host=28:EF:01:2D:EB:07,chrisKindle dhcp-host=08:EB:74:9D:47:53,humaxFreeview dhcp-host=2C:08:8C:CC:9A:9E,humaxYouview dhcp-host=00:1F:E2:4E:8F:CA,maxineStudy dhcp-host=00:25:36:AE:52:9C,192.168.1.50 My laptop seems to lose its IP address whenever I move from one Draytek's WiFi to the other but only when the IP is assigned by dnsmasq. If I connect to my guest network (192.168.6.x) then I get a IP address assigned by the 2860n and a good connection to the outside world. If I then reconnect to the 'local' WiFi the laptop loses its IP address. It's as if dnsmasq doesn't see the disconnection and doesn't answer the new DHCP broadcast from my laptop. If I leave it disconnected for a minute or two and then re-connect to the WiFi it *does* get an IP. Can anyone explain what might be wrong and/or a fix or workaround? -- Chris Green ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] DHCP problem when moving from one WiFi SSID to another
On 12/26/2018 6:58 PM, Chris Green wrote: > I have a large[ish[ house and to provide good WiFi throughout I run > two Draytek routers. The 'main' one is a Vigor 2860n which connects > to the internet by FTTC, the second one is an old Vigor 2820n which > has its WAN disabled and the LAN hardwired to the 2860n LAN. > > Currently I'm using the same SSID on both routers, I've read quite a > lot around this and the weight of opinion seems to be that using the > same SSID should work OK and is more transparent to the user than > using different ones. However I have also tried different SSIDs for > the two routers requiring user intervention to move from one to the > other, this shows the same symptoms (described below) as using the > same SSID. > > What happens is that when I move around such that the WiFi connection > should move from the 2820n to the 2860n my laptop loses its IP > address. > > DHCP and DNS is provided by dnsmasq running on a RaspberryPi, the > basic IPV4 setup is as follows:- > > Vigor 2860n - 192.168.1.1 > Raspberry Pi - 192.168.1.2 (runs dnsmasq) > Desktop 192.168.1.3 > Vigor 2820n - 192.168.1.20 > > The Pi assigns IP addresses from 192.168.80 to 192.168.1.127 and the > conf file is:- > > domain-needed > bogus-priv > expand-hosts > domain=zbmc.eu > dhcp-range=192.168.1.80,192.168.1.127,12h > dhcp-option=3,192.168.1.1 > local=/zbmc.eu/ > cname=bbb,beaglebone > cname=mx201,maxine-X201 > cname=ben,DESKTOP-978VD5M > cname=oki,MC342-AE529C > dhcp-host=00:BB:3A:E9:A3:15,maxineKindle > dhcp-host=00:09:B0:C9:CE:81,onkyoTx-nr616 > dhcp-host=28:EF:01:2D:EB:07,chrisKindle > dhcp-host=08:EB:74:9D:47:53,humaxFreeview > dhcp-host=2C:08:8C:CC:9A:9E,humaxYouview > dhcp-host=00:1F:E2:4E:8F:CA,maxineStudy > dhcp-host=00:25:36:AE:52:9C,192.168.1.50 > > > My laptop seems to lose its IP address whenever I move from one > Draytek's WiFi to the other but only when the IP is assigned by > dnsmasq. If I connect to my guest network (192.168.6.x) then I get a > IP address assigned by the 2860n and a good connection to the outside > world. If I then reconnect to the 'local' WiFi the laptop loses its > IP address. It's as if dnsmasq doesn't see the disconnection and > doesn't answer the new DHCP broadcast from my laptop. If I leave it > disconnected for a minute or two and then re-connect to the WiFi it > *does* get an IP. > > > Can anyone explain what might be wrong and/or a fix or workaround? > > How is this issue different from the one you posted a fiew mounths back (1)? Did you try what Simon Kellie suggested then? 1) http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2018q2/012225.html -- John Doe ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] DHCP problem when moving from one WiFi SSID to another
On Thu, Dec 27, 2018 at 08:26:25AM +0100, john doe wrote: > On 12/26/2018 6:58 PM, Chris Green wrote: > > I have a large[ish[ house and to provide good WiFi throughout I run > > two Draytek routers. The 'main' one is a Vigor 2860n which connects > > to the internet by FTTC, the second one is an old Vigor 2820n which > > has its WAN disabled and the LAN hardwired to the 2860n LAN. > > > > Currently I'm using the same SSID on both routers, I've read quite a > > lot around this and the weight of opinion seems to be that using the > > same SSID should work OK and is more transparent to the user than > > using different ones. However I have also tried different SSIDs for > > the two routers requiring user intervention to move from one to the > > other, this shows the same symptoms (described below) as using the > > same SSID. > > > > What happens is that when I move around such that the WiFi connection > > should move from the 2820n to the 2860n my laptop loses its IP > > address. > > > > DHCP and DNS is provided by dnsmasq running on a RaspberryPi, the > > basic IPV4 setup is as follows:- > > > > Vigor 2860n - 192.168.1.1 > > Raspberry Pi - 192.168.1.2 (runs dnsmasq) > > Desktop 192.168.1.3 > > Vigor 2820n - 192.168.1.20 > > > > The Pi assigns IP addresses from 192.168.80 to 192.168.1.127 and the > > conf file is:- > > > > domain-needed > > bogus-priv > > expand-hosts > > domain=zbmc.eu > > dhcp-range=192.168.1.80,192.168.1.127,12h > > dhcp-option=3,192.168.1.1 > > local=/zbmc.eu/ > > cname=bbb,beaglebone > > cname=mx201,maxine-X201 > > cname=ben,DESKTOP-978VD5M > > cname=oki,MC342-AE529C > > dhcp-host=00:BB:3A:E9:A3:15,maxineKindle > > dhcp-host=00:09:B0:C9:CE:81,onkyoTx-nr616 > > dhcp-host=28:EF:01:2D:EB:07,chrisKindle > > dhcp-host=08:EB:74:9D:47:53,humaxFreeview > > dhcp-host=2C:08:8C:CC:9A:9E,humaxYouview > > dhcp-host=00:1F:E2:4E:8F:CA,maxineStudy > > dhcp-host=00:25:36:AE:52:9C,192.168.1.50 > > > > > > My laptop seems to lose its IP address whenever I move from one > > Draytek's WiFi to the other but only when the IP is assigned by > > dnsmasq. If I connect to my guest network (192.168.6.x) then I get a > > IP address assigned by the 2860n and a good connection to the outside > > world. If I then reconnect to the 'local' WiFi the laptop loses its > > IP address. It's as if dnsmasq doesn't see the disconnection and > > doesn't answer the new DHCP broadcast from my laptop. If I leave it > > disconnected for a minute or two and then re-connect to the WiFi it > > *does* get an IP. > > > > > > Can anyone explain what might be wrong and/or a fix or workaround? > > > > > > How is this issue different from the one you posted a fiew mounths back (1)? > > Did you try what Simon Kellie suggested then? > > 1) > http://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2018q2/012225.html > He didn't really. :-) He said:- "but I don't have any concrete suggestions on how to fix it. I think the SSID change is a red-herring." But, yes, it is basically the same issue, but now I'm not changing SSID. I have now changed the dnsmasq configuration to set dhcp-authoritative, maybe that will do something. -- Chris Green ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] DHCP problem when moving from one WiFi SSID to another
> On 27 Dec 2018, at 08:45, Chris Green wrote: > >>> >>> >>> My laptop seems to lose its IP address whenever I move from one >>> Draytek's WiFi to the other but only when the IP is assigned by >>> dnsmasq. If I connect to my guest network (192.168.6.x) then I get a >>> IP address assigned by the 2860n and a good connection to the outside >>> world. If I then reconnect to the 'local' WiFi the laptop loses its >>> IP address. It's as if dnsmasq doesn't see the disconnection and >>> doesn't answer the new DHCP broadcast from my laptop. If I leave it >>> disconnected for a minute or two and then re-connect to the WiFi it >>> *does* get an IP. >>> >>> >>> Can anyone explain what might be wrong and/or a fix or workaround? >>> >>> > > He didn't really. :-) He said:- > > "but I don't have any concrete suggestions on how to fix it. I think the SSID > change > is a red-herring." > > But, yes, it is basically the same issue, but now I'm not changing SSID. > > I have now changed the dnsmasq configuration to set > dhcp-authoritative, maybe that will do something. One of the things that has always bothered me about these ‘linking lan switch ports between two wifi APs/one wifi AP/Router’ scenarios is the numerous levels of packet switching/bridging going on. I dimly remember one of my own setups using a ‘dual AP’ that would happily roam from AP1 to AP2 but not the other way…until a bridge table entry timed out. I wonder if that’s what is going on here? The common scenario in terms of bridging/switching is something like (in the linux world): AP1 Wifi Interface (or interfaces, think 2.4Ghz & 5Ghz radios) and LAN cpu interface are software bridged together. So there’s bridge learning of which MAC is on which bridge port going on there. The LAN cpu interface itself is often a hardware switch with built in learning of which MAC is on which physical switch port. One of those ports is physically connected to AP2 which has: AP2 A LAN port as part of a hardware switch with built in learning of which MAC address is on which port presented to the cpu as a LAN cpu port. This is software bridged to a Wifi interface (or interfaces, think 2.4Ghz & 5Ghz radios) which has to learn which MAC appears on which port. Roaming from one wireless radio on one AP to another wireless radio on another AP involves quite a lot of bridge table changes, I’m amazed it works at all. Cheers, Kevin D-B 012C ACB2 28C6 C53E 9775 9123 B3A2 389B 9DE2 334A ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
