Re: [Dnsmasq-discuss] Lease comes back after removing
On 2019-07-01 02:08, Geert Stappers wrote: > On 01-07-2019 10:41, Nicolas Cavallari wrote: > >> On 26/06/2019 22:32, Geert Stappers wrote: >>> My (educated??) guess is that lease data is stored in Dbus. >>> >>> My only point to back that up, is `dnsmasq -v` showing "DBus" >> D-Bus does not store data, it's merely an old-style RPC. >> >> dnsmasq does not send any D-Bus message when giving out leases, it merely >> provides an API to add/remove them while it is running. >> >> Without any lease file or lease script, dnsmasq has no way to have a memory >> of >> the lease. >> >> maybe it's just the client sending a DHCPREQUEST directly with the old lease, >> and dnsmasq being to eager to give it out ? >> > A network sniff ( tcpdump / tshark / wireshark ) would be helpfull > > > Cheers > > Geert Stappers > > > Willing to analyze a libpcap network sniff file. I'll have to do a tcpdump on it at some point. But the device can't remember the old lease (it doesn't store it in nonvolatile memory) so it should ask like new. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Lease comes back after removing
On 01-07-2019 10:41, Nicolas Cavallari wrote: > On 26/06/2019 22:32, Geert Stappers wrote: >> My (educated??) guess is that lease data is stored in Dbus. >> >> My only point to back that up, is `dnsmasq -v` showing "DBus" > D-Bus does not store data, it's merely an old-style RPC. > > dnsmasq does not send any D-Bus message when giving out leases, it merely > provides an API to add/remove them while it is running. > > Without any lease file or lease script, dnsmasq has no way to have a memory of > the lease. > > maybe it's just the client sending a DHCPREQUEST directly with the old lease, > and dnsmasq being to eager to give it out ? > A network sniff ( tcpdump / tshark / wireshark ) would be helpfull Cheers Geert Stappers Willing to analyze a libpcap network sniff file. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Lease comes back after removing
On 26/06/2019 22:32, Geert Stappers wrote: > > My (educated??) guess is that lease data is stored in Dbus. > > My only point to back that up, is `dnsmasq -v` showing "DBus" D-Bus does not store data, it's merely an old-style RPC. dnsmasq does not send any D-Bus message when giving out leases, it merely provides an API to add/remove them while it is running. Without any lease file or lease script, dnsmasq has no way to have a memory of the lease. maybe it's just the client sending a DHCPREQUEST directly with the old lease, and dnsmasq being to eager to give it out ? ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Lease comes back after removing, DBus
On 2019-06-26 22:09, Geert Stappers wrote: > On Wed, Jun 26, 2019 at 06:20:32PM -0700, A C wrote: >> On 2019-06-26 13:32, Geert Stappers wrote: >>> On 24-06-2019 02:38, A C wrote: > >>> On 23-06-2019 08:06, A C wrote: >>> I'm having trouble removing leases from my system. > ... There seems to be some kind of persistence that exists outside of just the lease file but I don't know where that is. This isn't the first time this has happened and it's happened with different embedded devices and non-embedded devices (cameras, AP's, IoTs, phones, etc.) there just seems to be sticky lease data somewhere. >>> You are probadly right about the "sticky lease data somewhere" >>> (I'm not comfortable to say "you are right about sticky lease data" ) >>> >>> The lease file I removed had size of zero bytes. >>> >>> My (educated??) guess is that lease data is stored in Dbus. >>> My only point to back that up, is `dnsmasq -v` showing "DBus" >> >> Yes, my copy does have DBus support. I've turned on dbus-monitor to see >> if anything shows up at the next lease update. There's enough devices I >> shouldn't have to wait long. > > This email is to express that I'm looking forward to those test results. Well, either it's not doing anything with dbus or (more likely) I don't know the magic incantation to dbus-monitor to have it show anything. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Lease comes back after removing, DBus
On Wed, Jun 26, 2019 at 06:20:32PM -0700, A C wrote: > On 2019-06-26 13:32, Geert Stappers wrote: > > On 24-06-2019 02:38, A C wrote: > > On 23-06-2019 08:06, A C wrote: > > > >> I'm having trouble removing leases from my system. ... > >> There seems to be some kind of persistence that exists outside of just > >> the lease file but I don't know where that is. This isn't the first > >> time this has happened and it's happened with different embedded devices > >> and non-embedded devices (cameras, AP's, IoTs, phones, etc.) there just > >> seems to be sticky lease data somewhere. > >> > > You are probadly right about the "sticky lease data somewhere" > > (I'm not comfortable to say "you are right about sticky lease data" ) > > > > The lease file I removed had size of zero bytes. > > > > My (educated??) guess is that lease data is stored in Dbus. > > My only point to back that up, is `dnsmasq -v` showing "DBus" > > Yes, my copy does have DBus support. I've turned on dbus-monitor to see > if anything shows up at the next lease update. There's enough devices I > shouldn't have to wait long. This email is to express that I'm looking forward to those test results. Groeten Geert Stappers P.S. The addition of 'DBus' to the subject is for inviting mailinglist subscribers in this discussion. -- Leven en laten leven ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Lease comes back after removing
On 2019-06-26 13:32, Geert Stappers wrote: > On 24-06-2019 02:38, A C wrote: > >> On 2019-06-23 11:08, Geert Stappers wrote: >>> On Sun, Jun 23, 2019 at 09:33:21AM -0700, A C wrote: On 2019-06-23 03:32, Geert Stappers wrote: > On 23-06-2019 08:06, A C wrote: > >> I'm having trouble removing leases from my system. >> I have: >> >> /etc/dnsmasq.conf: >> read-ethers ###(there is a dash) >> dhcp-range=10.0.200.100,10.0.200.105,255.255.0.0,12h >> ### My netmask is actually 255.255.0.0 on the network, all dhcp leases >> are in 10.0.200.x, static assignments are in other subnets >> >> /etc/ethers: >> 00:25:9C:1C:0A:C3 ap.lan >> ### and others >> >> /etc/hosts: >> 10.0.0.252 ap.lan >> ### and others >> >> >> How can I fully purge the lease and get it to start over? The client is >> an embedded device and has no memory of the lease once I power cycle it >> so somehow dnsmasq is remembering even though the lease file was purged. >> > Recently I had simular sympthoms, infact still have them. > > > My only issue is when I forget to add a client to the list > prior to first putting it online and it acquires a lease from the DHCP > lease pool instead of the IP I want to give it via the combination of > ethers/hosts. After that I have extreme difficulty purging the lease to > force a new address. >>> My /etc/ethers has a line like >>> >>> 00:02:b0:ef:f0:ef kornuit >>> >>> Doing `host kornuit` returns correctly the IPv4 address that is in DNS. >>> (other DNS as dnsmasq ( no kornuit entry in /etc/hosts )) >>> >>> >>> I also stopped dnsmasq, removed the lease file and restarted dnsmasq. >>> >>> Did another PXE netboot ( consider it an embedded device, it has no >>> memory of previous lease ) >>> >>> Server kornuit got the IPv4 address as before, one from the Dnsmasq >>> DHCP range. Where it looks like a persistent DHCP lease, do I think >>> that it is algoritme that hands out each time the same IPv4 address. >>> >>> Thing I need to verify is if dnsmasq does do a DNS-lookup on 'kornuit' >>> after reading /etc/ethers. > > Now using `dhcp-host=MA:CA:DD:RE:SS,192.0.2.42 > >> host ap.lan localhost (run on the same server as dnsmasq) returns >> 10.0.0.252 as expected. >> >> Turned off the device, stopped dnsmasq, removed the lease from the lease >> file, restarted dnsmasq and then restarted the device. I get the old >> DHCP range lease instead of the one defined in hosts. >> >> If I add a host entry (with an IP outside of the DHCP range) and an >> ethers entry for a device bore I ever plug it into the network I will >> correctly get a static lease of the IP I define in hosts. If I forget >> to do that, the device picks up a lease from the DHCP range and then >> it's a massive fight to get rid of it. Sometimes I have to leave the >> device disconnected for a few days so the lease expires on its own >> (regardless of deleting the lease) and then I can switch the IP. >> >> There seems to be some kind of persistence that exists outside of just >> the lease file but I don't know where that is. This isn't the first >> time this has happened and it's happened with different embedded devices >> and non-embedded devices (cameras, AP's, IoTs, phones, etc.) there just >> seems to be sticky lease data somewhere. >> > You are probadly right about the "sticky lease data somewhere" > > (I'm not comfortable to say "you are right about sticky lease data" ) > > > The lease file I removed had size of zero bytes. > > > My (educated??) guess is that lease data is stored in Dbus. > > My only point to back that up, is `dnsmasq -v` showing "DBus" Yes, my copy does have DBus support. I've turned on dbus-monitor to see if anything shows up at the next lease update. There's enough devices I shouldn't have to wait long. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Lease comes back after removing
On 24-06-2019 02:38, A C wrote: > On 2019-06-23 11:08, Geert Stappers wrote: >> On Sun, Jun 23, 2019 at 09:33:21AM -0700, A C wrote: >>> On 2019-06-23 03:32, Geert Stappers wrote: On 23-06-2019 08:06, A C wrote: > I'm having trouble removing leases from my system. > I have: > > /etc/dnsmasq.conf: > read-ethers ###(there is a dash) > dhcp-range=10.0.200.100,10.0.200.105,255.255.0.0,12h > ### My netmask is actually 255.255.0.0 on the network, all dhcp leases > are in 10.0.200.x, static assignments are in other subnets > > /etc/ethers: > 00:25:9C:1C:0A:C3 ap.lan > ### and others > > /etc/hosts: > 10.0.0.252 ap.lan > ### and others > > > How can I fully purge the lease and get it to start over? The client is > an embedded device and has no memory of the lease once I power cycle it > so somehow dnsmasq is remembering even though the lease file was purged. > Recently I had simular sympthoms, infact still have them. My only issue is when I forget to add a client to the list prior to first putting it online and it acquires a lease from the DHCP lease pool instead of the IP I want to give it via the combination of ethers/hosts. After that I have extreme difficulty purging the lease to force a new address. >> My /etc/ethers has a line like >> >> 00:02:b0:ef:f0:ef kornuit >> >> Doing `host kornuit` returns correctly the IPv4 address that is in DNS. >> (other DNS as dnsmasq ( no kornuit entry in /etc/hosts )) >> >> >> I also stopped dnsmasq, removed the lease file and restarted dnsmasq. >> >> Did another PXE netboot ( consider it an embedded device, it has no >> memory of previous lease ) >> >> Server kornuit got the IPv4 address as before, one from the Dnsmasq >> DHCP range. Where it looks like a persistent DHCP lease, do I think >> that it is algoritme that hands out each time the same IPv4 address. >> >> Thing I need to verify is if dnsmasq does do a DNS-lookup on 'kornuit' >> after reading /etc/ethers. Now using `dhcp-host=MA:CA:DD:RE:SS,192.0.2.42 > host ap.lan localhost (run on the same server as dnsmasq) returns > 10.0.0.252 as expected. > > Turned off the device, stopped dnsmasq, removed the lease from the lease > file, restarted dnsmasq and then restarted the device. I get the old > DHCP range lease instead of the one defined in hosts. > > If I add a host entry (with an IP outside of the DHCP range) and an > ethers entry for a device bore I ever plug it into the network I will > correctly get a static lease of the IP I define in hosts. If I forget > to do that, the device picks up a lease from the DHCP range and then > it's a massive fight to get rid of it. Sometimes I have to leave the > device disconnected for a few days so the lease expires on its own > (regardless of deleting the lease) and then I can switch the IP. > > There seems to be some kind of persistence that exists outside of just > the lease file but I don't know where that is. This isn't the first > time this has happened and it's happened with different embedded devices > and non-embedded devices (cameras, AP's, IoTs, phones, etc.) there just > seems to be sticky lease data somewhere. > You are probadly right about the "sticky lease data somewhere" (I'm not comfortable to say "you are right about sticky lease data" ) The lease file I removed had size of zero bytes. My (educated??) guess is that lease data is stored in Dbus. My only point to back that up, is `dnsmasq -v` showing "DBus" Cheers Geert Stappers ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Lease comes back after removing
On 2019-06-23 11:08, Geert Stappers wrote: > On Sun, Jun 23, 2019 at 09:33:21AM -0700, A C wrote: >> On 2019-06-23 03:32, Geert Stappers wrote: >>> On 23-06-2019 08:06, A C wrote: >>> I'm having trouble removing leases from my system. I have a client that accepted a lease in my DHCP range before I remembered to put it in /etc/ethers and /etc/hosts to give it a static lease. I turned off the client, stopped dnsmasq, removed the lease file entry in /var/lib/misc/dnsmasq.leases and then restarted dnsmasq. Then I restarted the client. It again found the original lease in my DHCP range instead of picking one from /etc/ethers (in fact it reports "not giving name ap.lan to the DHCP lease of 10.0.200.102 because the name exists in /etc/hosts with address 10.0.0.252"). > > Please check if I understand that, > that the configuration is simular to this: > > /etc/dnsmasq.conf: > > dchp-range=10.0.200.101-10.0.200.150 > readethers > > > /etc/ethers > 00:00:ca:fe:be:ef ap.lan > > > /etc/hosts > > 10.0.0.252 ap.lan I have: /etc/dnsmasq.conf: read-ethers ###(there is a dash) dhcp-range=10.0.200.100,10.0.200.105,255.255.0.0,12h ### My netmask is actually 255.255.0.0 on the network, all dhcp leases are in 10.0.200.x, static assignments are in other subnets /etc/ethers: 00:25:9C:1C:0A:C3 ap.lan ### and others /etc/hosts: 10.0.0.252 ap.lan ### and others > > > How can I fully purge the lease and get it to start over? The client is an embedded device and has no memory of the lease once I power cycle it so somehow dnsmasq is remembering even though the lease file was purged. >>> Recently I had simular sympthoms, infact still have them. >>> >>> It give me the akward feeling that `readethers` does not work as I expect. >>> >>> Because it was the first time that i used Dnsmasq with /etc/ethers I >>> choose to continue with the netboots I have to do. >>> >>> >>> Yes, most likely will it bite me another time. >>> >>> Meanwhile send your report of (successfull) mapping of IPv4 address on >>> MAC address through /etc/ethers >> >> /etc/ethers works fine for me, I have 50 clients listed in it, no issues. > > Acknowledge on that. ( and no questions asked why it works fine ) > > >> My only issue is when I forget to add a client to the list >> prior to first putting it online and it acquires a lease from the DHCP >> lease pool instead of the IP I want to give it via the combination of >> ethers/hosts. After that I have extreme difficulty purging the lease to >> force a new address. > > > My /etc/ethers has a line like > > 00:02:b0:ef:f0:ef kornuit > > Doing `host kornuit` returns correctly the IPv4 address that is in DNS. > (other DNS as dnsmasq ( no kornuit entry in /etc/hosts )) > > > I also stopped dnsmasq, removed the lease file and restarted dnsmasq. > > Did another PXE netboot ( consider it an embedded device, it has no > memory of previous lease ) > > Server kornuit got the IPv4 address as before, one from the Dnsmasq > DHCP range. Where it looks like a persistent DHCP lease, do I think > that it is algoritme that hands out each time the same IPv4 address. > > Thing I need to verify is if dnsmasq does do a DNS-lookup on 'kornuit' > after reading /etc/ethers. host ap.lan localhost (run on the same server as dnsmasq) returns 10.0.0.252 as expected. Turned off the device, stopped dnsmasq, removed the lease from the lease file, restarted dnsmasq and then restarted the device. I get the old DHCP range lease instead of the one defined in hosts. If I add a host entry (with an IP outside of the DHCP range) and an ethers entry for a device bore I ever plug it into the network I will correctly get a static lease of the IP I define in hosts. If I forget to do that, the device picks up a lease from the DHCP range and then it's a massive fight to get rid of it. Sometimes I have to leave the device disconnected for a few days so the lease expires on its own (regardless of deleting the lease) and then I can switch the IP. There seems to be some kind of persistence that exists outside of just the lease file but I don't know where that is. This isn't the first time this has happened and it's happened with different embedded devices and non-embedded devices (cameras, AP's, IoTs, phones, etc.) there just seems to be sticky lease data somewhere. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Lease comes back after removing
On Sun, Jun 23, 2019 at 09:33:21AM -0700, A C wrote: > On 2019-06-23 03:32, Geert Stappers wrote: > > On 23-06-2019 08:06, A C wrote: > > > >> I'm having trouble removing leases from my system. I have a client that > >> accepted a lease in my DHCP range before I remembered to put it in > >> /etc/ethers and /etc/hosts to give it a static lease. > >> > >> I turned off the client, stopped dnsmasq, removed the lease file entry > >> in /var/lib/misc/dnsmasq.leases and then restarted dnsmasq. Then I > >> restarted the client. It again found the original lease in my DHCP > >> range instead of picking one from /etc/ethers (in fact it reports "not > >> giving name ap.lan to the DHCP lease of 10.0.200.102 because the name > >> exists in /etc/hosts with address 10.0.0.252"). Please check if I understand that, that the configuration is simular to this: /etc/dnsmasq.conf: dchp-range=10.0.200.101-10.0.200.150 readethers /etc/ethers 00:00:ca:fe:be:ef ap.lan /etc/hosts 10.0.0.252 ap.lan > >> How can I fully purge the lease and get it to start over? The client is > >> an embedded device and has no memory of the lease once I power cycle it > >> so somehow dnsmasq is remembering even though the lease file was purged. > >> > > Recently I had simular sympthoms, infact still have them. > > > > It give me the akward feeling that `readethers` does not work as I expect. > > > > Because it was the first time that i used Dnsmasq with /etc/ethers I > > choose to continue with the netboots I have to do. > > > > > > Yes, most likely will it bite me another time. > > > > Meanwhile send your report of (successfull) mapping of IPv4 address on > > MAC address through /etc/ethers > > /etc/ethers works fine for me, I have 50 clients listed in it, no issues. Acknowledge on that. ( and no questions asked why it works fine ) > My only issue is when I forget to add a client to the list > prior to first putting it online and it acquires a lease from the DHCP > lease pool instead of the IP I want to give it via the combination of > ethers/hosts. After that I have extreme difficulty purging the lease to > force a new address. My /etc/ethers has a line like 00:02:b0:ef:f0:ef kornuit Doing `host kornuit` returns correctly the IPv4 address that is in DNS. (other DNS as dnsmasq ( no kornuit entry in /etc/hosts )) I also stopped dnsmasq, removed the lease file and restarted dnsmasq. Did another PXE netboot ( consider it an embedded device, it has no memory of previous lease ) Server kornuit got the IPv4 address as before, one from the Dnsmasq DHCP range. Where it looks like a persistent DHCP lease, do I think that it is algoritme that hands out each time the same IPv4 address. Thing I need to verify is if dnsmasq does do a DNS-lookup on 'kornuit' after reading /etc/ethers. Groeten Geert Stappers -- Leven en laten leven ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Lease comes back after removing
On 2019-06-23 03:32, Geert Stappers wrote: > On 23-06-2019 08:06, A C wrote: > >> I'm having trouble removing leases from my system. I have a client that >> accepted a lease in my DHCP range before I remembered to put it in >> /etc/ethers and /etc/hosts to give it a static lease. >> >> I turned off the client, stopped dnsmasq, removed the lease file entry >> in /var/lib/misc/dnsmasq.leases and then restarted dnsmasq. Then I >> restarted the client. It again found the original lease in my DHCP >> range instead of picking one from /etc/ethers (in fact it reports "not >> giving name ap.lan to the DHCP lease of 10.0.200.102 because the name >> exists in /etc/hosts with address 10.0.0.252"). >> >> How can I fully purge the lease and get it to start over? The client is >> an embedded device and has no memory of the lease once I power cycle it >> so somehow dnsmasq is remembering even though the lease file was purged. >> > Recently I had simular sympthoms, infact still have them. > > It give me the akward feeling that `readethers` does not work as I expect. > > Because it was the first time that i used Dnsmasq with /etc/ethers I > choose to continue with the netboots I have to do. > > > Yes, most likely will it bite me another time. > > Meanwhile send your report of (successfull) mapping of IPv4 address on > MAC address through /etc/ethers > > > Cheers > > Geert Stappers /etc/ethers works fine for me, I have 50 clients listed in it, no issues. My only issue is when I forget to add a client to the list prior to first putting it online and it acquires a lease from the DHCP lease pool instead of the IP I want to give it via the combination of ethers/hosts. After that I have extreme difficulty purging the lease to force a new address. ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
Re: [Dnsmasq-discuss] Lease comes back after removing
On 23-06-2019 08:06, A C wrote: > I'm having trouble removing leases from my system. I have a client that > accepted a lease in my DHCP range before I remembered to put it in > /etc/ethers and /etc/hosts to give it a static lease. > > I turned off the client, stopped dnsmasq, removed the lease file entry > in /var/lib/misc/dnsmasq.leases and then restarted dnsmasq. Then I > restarted the client. It again found the original lease in my DHCP > range instead of picking one from /etc/ethers (in fact it reports "not > giving name ap.lan to the DHCP lease of 10.0.200.102 because the name > exists in /etc/hosts with address 10.0.0.252"). > > How can I fully purge the lease and get it to start over? The client is > an embedded device and has no memory of the lease once I power cycle it > so somehow dnsmasq is remembering even though the lease file was purged. > Recently I had simular sympthoms, infact still have them. It give me the akward feeling that `readethers` does not work as I expect. Because it was the first time that i used Dnsmasq with /etc/ethers I choose to continue with the netboots I have to do. Yes, most likely will it bite me another time. Meanwhile send your report of (successfull) mapping of IPv4 address on MAC address through /etc/ethers Cheers Geert Stappers ___ Dnsmasq-discuss mailing list Dnsmasq-discuss@lists.thekelleys.org.uk http://lists.thekelleys.org.uk/mailman/listinfo/dnsmasq-discuss
