Re: goose DHCP clients to new address Was: DHCP Problem
On Sun, 3 Dec 2023 17:18:23 -0500 Jeffrey Walton wrote: > I don't know about Linux clients, but in the past, Windows clients > used to try to connect to the previous DHCP server for its lease info. > If the old DHCP server is still available (on the old router?), then > the client may be getting the lease info from the old server. To avoid > the problem, we disconnected the old server from the network. I did shut down both the old server and its failover peer. Clients I haven't mucked with are now asking for leases from the new server. Dec 03 14:55:48 issola dhcpd[24072]: failover peer failover-partner: I move from startup to communications-interrupted Dec 03 15:09:46 issola dhcpd[24072]: DHCPREQUEST for 192.168.100.45 from ec:28:d3:7a:6a:76 via enp1s0 Dec 03 15:09:46 issola dhcpd[24072]: DHCPACK on 192.168.100.45 to ec:28:d3:7a:6a:76 via enp1s0 Dec 03 15:40:50 issola dhcpd[24072]: DHCPREQUEST for 192.168.100.45 from ec:28:d3:7a:6a:76 via enp1s0 Dec 03 15:40:50 issola dhcpd[24072]: DHCPACK on 192.168.100.45 to ec:28:d3:7a:6a:76 via enp1s0 But that guy is still pointing toward the old router. > > You should probably just perform a hard cut-over. Shutdown the old > router, stand up the new router. After the hard cutover, force clients > to renew their leases (or wait until they do it on their own). And if > things go sideways, undo the change. I may yet do that. The change will consist of pulling the Ethernet cable between the old router and its upstream connection. -- Does anybody read signatures any more? https://charlescurley.com https://charlescurley.com/blog/
Re: goose DHCP clients to new address Was: DHCP Problem
On Sun, Dec 3, 2023 at 4:51 PM Charles Curley wrote: > > On Sun, 3 Dec 2023 22:14:51 +0100 > Geert Stappers wrote: > > > I assume that the previous router is disconnected from the LAN. > > No. Until I solve this problem (and a few others), I will have clients > using the old router. > > > The DHCProtocol has "release" for such goosing. > > At DHCPclient do "stop DHCP", over the wire goes DHCPRELEASE [0] > > The DHCPclient should forget ( "release" ) previous settings. > > At DHCPclient do "start DHCP", client should get fresh config, > > including the setting for the fresh router. > > I'm not sure how to do this. I did run on a client > > dhclient -r > dhclient > > I observed no changes. > > The -r causes dhclient to release its lease. Invoking dhclient again > should then obtain a new lease. I don't know about Linux clients, but in the past, Windows clients used to try to connect to the previous DHCP server for its lease info. If the old DHCP server is still available (on the old router?), then the client may be getting the lease info from the old server. To avoid the problem, we disconnected the old server from the network. You should probably just perform a hard cut-over. Shutdown the old router, stand up the new router. After the hard cutover, force clients to renew their leases (or wait until they do it on their own). And if things go sideways, undo the change. > > If that is already done, provide information to enable further help. > > Such as name of the DHCP client program and DHCP lease time. > > I am using whatever is standard on Debian Bullseye and Bookworm. > > root@hawk:/etc# pre dhc > isc-dhcp-client 4.4.1-2.3+deb11u2 amd64 > isc-dhcp-common 4.4.1-2.3+deb11u2 amd64 > root@hawk:/etc# > > root@tiassa:~# pre dhc > isc-dhcp-client 4.4.3-P1-2 amd64 > isc-dhcp-common 4.4.3-P1-2 amd64 > root@tiassa:~# > > The client's name is dhclient. > > default-lease-time 86400; # 24 hours > max-lease-time 172800;# 48 hours > > I think for the purposes of experimentation I will shorten those to > half an hour and one hours respectively. Jeff
Re: goose DHCP clients to new address Was: DHCP Problem
On Sun, 3 Dec 2023 22:14:51 +0100 Geert Stappers wrote: > I assume that the previous router is disconnected from the LAN. No. Until I solve this problem (and a few others), I will have clients using the old router. > The DHCProtocol has "release" for such goosing. > At DHCPclient do "stop DHCP", over the wire goes DHCPRELEASE [0] > The DHCPclient should forget ( "release" ) previous settings. > At DHCPclient do "start DHCP", client should get fresh config, > including the setting for the fresh router. I'm not sure how to do this. I did run on a client dhclient -r dhclient I observed no changes. The -r causes dhclient to release its lease. Invoking dhclient again should then obtain a new lease. > > > If that is already done, provide information to enable further help. > Such as name of the DHCP client program and DHCP lease time. I am using whatever is standard on Debian Bullseye and Bookworm. root@hawk:/etc# pre dhc isc-dhcp-client 4.4.1-2.3+deb11u2 amd64 isc-dhcp-common 4.4.1-2.3+deb11u2 amd64 root@hawk:/etc# root@tiassa:~# pre dhc isc-dhcp-client 4.4.3-P1-2 amd64 isc-dhcp-common 4.4.3-P1-2 amd64 root@tiassa:~# The client's name is dhclient. default-lease-time 86400; # 24 hours max-lease-time 172800;# 48 hours I think for the purposes of experimentation I will shorten those to half an hour and one hours respectively. -- Does anybody read signatures any more? https://charlescurley.com https://charlescurley.com/blog/
goose DHCP clients to new address Was: DHCP Problem
On Sun, Dec 03, 2023 at 12:30:53PM -0700, Charles Curley wrote: > I am installing a new router which seems to work well so far. I assume that the previous router is disconnected from the LAN. > I have changed the DHCP server to use the new router's address, and shut > the server down and restarted it. Existing clients insist on using the > old router anyway. Is there any way to goose clients into using the new > one short of manually using the ip route command? The DHCProtocol has "release" for such goosing. At DHCPclient do "stop DHCP", over the wire goes DHCPRELEASE [0] The DHCPclient should forget ( "release" ) previous settings. At DHCPclient do "start DHCP", client should get fresh config, including the setting for the fresh router. If that is already done, provide information to enable further help. Such as name of the DHCP client program and DHCP lease time. Oh, DHCP lease time: What lease time is the DHCP server providing? Groeten Geert Stappers [0] https://en.wikipedia.org/wiki/Dynamic_Host_Configuration_Protocol#DHCP_message_types -- Silence is hard to parse
Re: Difference between dhcp clients
i needed to install a dhcp3-client to get a hook on my lan. probably the dhcp server is dhcp3 too ... last time i tried, dhcp-client (and thus server) was still installed as default client at debian install. piem On Wednesday 23 July 2003 02:14, Nicolas wrote: Which of the dhcp client is the best for a router/firewall? dhcp-client, dhcp3-client, dhcpcd or udhcpc? Nic Cola -- Kettering's Observation: Logic is an organized way of going wrong with confidence. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Re: Difference between dhcp clients
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 On Tue, Jul 22, 2003 at 09:14:46PM -0400, Nicolas wrote: Which of the dhcp client is the best for a router/firewall? dhcp-client, dhcp3-client, dhcpcd or udhcpc? I go with dhcp3-client because it's the current version and it works. - -- .''`. Paul Johnson [EMAIL PROTECTED] : :' :proud Debian admin and user `. `'` `- Debian - when you have better things to do than fix a system -BEGIN PGP SIGNATURE- Version: GnuPG v1.2.2 (GNU/Linux) iD8DBQE/H+27J5vLSqVpK2kRAvQ6AJ4q0Xn9TS/5ZCUHjhE0+lIjTfQnUQCeJ1dW RDUXP/hxLKWVZ47wE+LFNPM= =ZOGQ -END PGP SIGNATURE- -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
Difference between dhcp clients
Which of the dhcp client is the best for a router/firewall? dhcp-client, dhcp3-client, dhcpcd or udhcpc? Nic Cola -- Kettering's Observation: Logic is an organized way of going wrong with confidence. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of unsubscribe. Trouble? Contact [EMAIL PROTECTED]
hostnames for dhcp clients with bind
Hi there, I managed to set up a dhcp server to hand out ip addresses to clients, now I want these clients to get a hostname depending on their MAC address to be resolved by bind. Has anyone successfully set up such a configuration and can give me a quick overview what needs to be done, or point me to some documentation on the internet? I already googled myself, but there are mostly unanswered or misunderstood questions on mailing list archives.. I also had a look at dhcp-dns, but I am not sure if it is what I want since it is run as cronjob, which seems strange to me. I have to say that I am not too familiar with the configuration of bind to be used to resolve local hostnames.. Any help is appreciated thanks in advance Stefan -- boredom is not a burden anyone should bear signature.asc Description: This is a digitally signed message part
Re: hostnames for dhcp clients with bind
Stefan Radomski wrote:
Hi there,
I managed to set up a dhcp server to hand out ip addresses to clients,
now I want these clients to get a hostname depending on their MAC
address to be resolved by bind.
Has anyone successfully set up such a configuration and can give me a
quick overview what needs to be done, or point me to some documentation
on the internet?
What you want is dynDNS with ISC dhcpd3:
dhcp3-client - DHCP Client
dhcp3-common - Common files used by all the dhcp3* packages.
dhcp3-dev - API for accessing and modifying the DHCP server and client state
dhcp3-relay - DHCP Relay
dhcp3-server - DHCP server for automatic IP address assignment
It makes the DNS entries when a client registers with the DHCP server
(either the client provides its name and the server accepts it or you have
host directives with mac adresses that specify the name of the client:
host sdfg {
hardware ethernet xx:xx:xx:xx:xx:xx;
ddns-hostname sdfg;
}
That even works with printers and bootp.
If you really want IP management with your bind server, use host statements
in the dhcpd.conf. You can use hostnames instead of ip adresses there, too.
But then you have to configure the name at the client _and_ the server which
defeats the point of it.
I even run such a setup (dynDNS) at home because it makes it absolutely easy
to use and maintain :)
HS
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DHCP clients
This is a question more for curiousity than anything else, but here it goes... I see several dhcp clients available: pump, dhcpcd, and dhcp-client. There's almost certainly more available that aren't debianized. I was wondering what the differences are between them, which one people recommend and why. For my part, i've been using pump, patched to have an option to cut down on the amount of junk it dumps to syslog (one day it filled my 400M /var partition... the next i patched it). Haven't had any problems other than that. -- finger for GPG public key. pgpSitZkgHeY2.pgp Description: PGP signature
Re: DHCP clients
On 2000-02-20 18:53:22, Brad wrote: I see several dhcp clients available: pump, dhcpcd, and dhcp-client. There's almost certainly more available that aren't debianized. I was wondering what the differences are between them, which one people recommend and why. dhcp-client has a hook that enables easy site configuration. For instance, I update my dyndns.org record in that script. /Allan -- Allan M. Wind Finger: [EMAIL PROTECTED] (GPG/PGP) P.O. Box 2022 Email: [EMAIL PROTECTED] Woburn, MA 01888-0022 ICQ: 44214251 USA Phone: 781.279.4513
Re: DHCP clients
For my part, i've been using pump, patched to have an option to cut down on the amount of junk it dumps to syslog (one day it filled my 400M /var partition... the next i patched it). Haven't had any problems other than that. Pump adds about twenty lines a day to my syslog, unpatched. Maybe they've improved it? -- Carl Fink [EMAIL PROTECTED] Manager, Dueling Modems Computer Forum http://dm.net
