Send dhcp-users mailing list submissions to
[email protected]
Advertising
To subscribe or unsubscribe via the World Wide Web, visit
https://lists.isc.org/mailman/listinfo/dhcp-users
or, via email, send a message with subject or body 'help' to
[email protected]
You can reach the person managing the list at
[email protected]
When replying, please edit your Subject line so it is more specific
than "Re: Contents of dhcp-users digest..."
Today's Topics:
1. Re: ISC-dhcp subnet limit? (Chris Buxton)
----------------------------------------------------------------------
Message: 1
Date: Sun, 31 Jan 2016 18:58:31 -0800
From: Chris Buxton <[email protected]>
To: Users of ISC DHCP <[email protected]>
Subject: Re: ISC-dhcp subnet limit?
Message-ID: <[email protected]>
Content-Type: text/plain; charset="utf-8"
If you should go back to using failover, you should increase
max-unacked-updates from its default of 10 to a more sane value like 1000.
Regards,
Chris
Sent from my iPhone
> On Jan 29, 2016, at 7:58 AM, Rob Morin <[email protected]> wrote:
>
> Hey Denis, thanks for the response...
>
> I was just using apt to install isc-dchp server on ubuntu 14.04
> Server is quad core xeon with 8 gigs of ram with a software raid 1 disks
>
> But maybe i should consider your way...
>
> I was just doing some testing using a ramdisk for the
> /var/lib/dhcp/dchpd.leases files
>
> Our leases are short for special reasons... 20 minutes
>
> so on a dev machine i created a ramdisk of 2 gigs, and backup the leases
> files to a hard disk each 5 mins, and on restart the
> /etc/init/isc-dhcp-server.conf will copy the files from backup to /ramdisk
> then start dhcp
>
> on dev it works fine... but i may consider your way now...
>
> we tend to shy away from compiling stuff.. :(
>
> Even after 24 hours after start of the peer never came out of recovery mode,
> not sure why..
>
> Currently we made dhcp-2 a standalone server and it currently has 217335
> leases in it, but i will need to double that at least in coming weeks..
>
> Server is currently ....
>
> top - 10:55:08 up 22:55, 2 users, load average: 2.00, 1.99, 1.93
> Tasks: 116 total, 1 running, 115 sleeping, 0 stopped, 0 zombie
> %Cpu0 : 0.9 us, 0.5 sy, 0.0 ni, 25.8 id, 72.8 wa, 0.0 hi, 0.0 si, 0.0
> st
> %Cpu1 : 1.4 us, 0.5 sy, 0.0 ni, 74.3 id, 23.4 wa, 0.0 hi, 0.5 si, 0.0
> st
> %Cpu2 : 0.0 us, 0.0 sy, 0.0 ni,100.0 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0
> st
> %Cpu3 : 0.5 us, 0.0 sy, 0.0 ni, 99.5 id, 0.0 wa, 0.0 hi, 0.0 si, 0.0
> st
> KiB Mem: 8092320 total, 5007076 used, 3085244 free, 164496 buffers
> KiB Swap: 7810044 total, 0 used, 7810044 free. 4129916 cached Mem
>
> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
>
>
>
> 12979 root 20 0 565060 559220 2524 D 2.3 6.9 15:08.17 dhcpd
>
>
>
> 1713 syslog 20 0 255848 2924 2428 S 0.9 0.0 3:16.05 rsyslogd
>
>
>
> 215 root 20 0 0 0 0 S 0.5 0.0 2:00.89
> jbd2/md2-8
>
>
> 412 root 0 -20 0 0 0 S 0.5 0.0 1:13.95
> kworker/0:1H
>
>
> 14300 root 20 0 0 0 0 S 0.5 0.0 0:41.33
> kworker/0:2
>
>
> 1 root 20 0 33620 4284 2824 S 0.0 0.1 0:01.19 init
>
>
> I will try your suggestion on dev machine
> Do you use or know of a tool that i can use to simulate dhcp request for
> testing on my dev machine?
>
> Thanks for your help!
> Rob Morin
> Montreal, Canada
>
> CE COURRIEL AINSI QUE CES DOCUMENTS JOINTS peuvent contenir des
> renseignements confidentiels et privil?gi?s. Si vous n??tes pas le
> destinataire d?sign?, veuillez nous en informer imm?diatement et effacer
> toute copie. Merci.
> THIS EMAIL AND THE DOCUMENTS ATTACHED may contain privileged or confidential
> information. If the reader of this message is not the intended recipient,
> please notify the sender immediately and delete the original message. Thank
> you.
>
>> On 2016-01-29 9:58 AM, Denis Laventure wrote:
>> Hi Rob,
>>
>> I can't help for issue on your interface problem but I think I can help with
>> the performance.
>>
>> I used to have performance problem with my failover setup and someone at ISC
>> told me to change some value in the code to get debug information about
>> memory usage.
>>
>> Add this to the file "includes/dhcpd.h"
>> #if !defined (REPORT_HASH_PERFORMANCE)
>> # define REPORT_HASH_PERFORMANCE 1
>> #endif
>>
>> Compile and start the daemon and you should get something like this on
>> screen and in the log:
>>
>> dhcpd: DHCP name hash: Contents/Size (%): 106/401 (26%). Min/max: 0/2
>> dhcpd: DHCP code hash: Contents/Size (%): 106/254 (41%). Min/max: 0/1
>> dhcpd: NWIP name hash: Contents/Size (%): 11/17 (64%). Min/max: 0/2
>> dhcpd: NWIP code hash: Contents/Size (%): 11/17 (64%). Min/max: 0/1
>> dhcpd: FQDN name hash: Contents/Size (%): 8/13 (61%). Min/max: 0/2
>> dhcpd: FQDN code hash: Contents/Size (%): 8/13 (61%). Min/max: 0/1
>> dhcpd: VIVCO name hash: Contents/Size (%): 1/127 (0%). Min/max: 0/1
>> dhcpd: VIVCO code hash: Contents/Size (%): 1/127 (0%). Min/max: 0/1
>> dhcpd: VIVSO name hash: Contents/Size (%): 1/127 (0%). Min/max: 0/1
>> dhcpd: VIVSO code hash: Contents/Size (%): 1/127 (0%). Min/max: 0/1
>> dhcpd: ISC name hash: Contents/Size (%): 2/3 (66%). Min/max: 0/1
>> dhcpd: ISC code hash: Contents/Size (%): 2/3 (66%). Min/max: 0/1
>> dhcpd: Relay Agent name hash: Contents/Size (%): 5/11 (45%). Min/max: 0/1
>> dhcpd: Relay Agent code hash: Contents/Size (%): 5/11 (45%). Min/max: 0/1
>> dhcpd: Server-Config Option name hash: Contents/Size (%): 67/136 (49%).
>> Min/max: 0/4
>> dhcpd: Server-Config Option code hash: Contents/Size (%): 67/136 (49%).
>> Min/max: 0/1
>> dhcpd: data: hardware: no raw packet or lease is available
>> dhcpd: data: hardware: no raw packet or lease is available
>> dhcpd: data: hardware: no raw packet or lease is available
>> dhcpd: data: hardware: no raw packet or lease is available
>> dhcpd: data: hardware: no raw packet or lease is available
>> dhcpd: data: hardware: no raw packet or lease is available
>> dhcpd: Config file: /dhcpd/dhcpd.conf
>> dhcpd: Database file: /dhcpd/dhcpd.leases
>> dhcpd: PID file: /var/run/dhcpd.pid
>> dhcpd: Wrote 0 class decls to leases file.
>> dhcpd: Wrote 0 deleted host decls to leases file.
>> dhcpd: Wrote 0 new dynamic host decls to leases file.
>> dhcpd: Wrote 48578 leases to leases file.
>> dhcpd: Host HW hash: Contents/Size (%): 1420/22501 (6%). Min/max: 0/4
>> dhcpd: Host UID hash: No table.
>> dhcpd: Lease IP hash: Contents/Size (%): 70324/100003 (70%). Min/max: 0/5
>> dhcpd: Lease UID hash: Contents/Size (%): 8708/100003 (8%). Min/max: 0/3
>> dhcpd: Lease HW hash: Contents/Size (%): 9036/100003 (9%). Min/max: 0/3
>>
>> "Lease IP hash" is where you should look.
>>
>> By default the server use a lease hash size value of 100003. I had over
>> 350000 leases so I was exceeding that value and the server was very slow to
>> start.
>>
>> To change the size you must edit the file "includes/dhcpd.h" and find
>> LEASE_HASH_SIZE and replace the value. This value must be a prime number (I
>> used 400009).
>>
>> -# define LEASE_HASH_SIZE 100003
>> +# define LEASE_HASH_SIZE 400009
>>
>> Compile and start again. That was the answer for me.
>>
>> One other thing with the failover setup, the peer will always be in recover
>> state when starting for the duration of the "MCLT" (time in second) in your
>> failover definition (1800 in your case), so it will be in recover start for
>> 30 minutes. I use 300 (5 minutes).
>>
>> Le texte aurait ?t? plus facile ? ?crire en fran?ais mais comme la liste est
>> en anglais et que ?a peut aider d'autres personnes alors je me suis forc?.
>> En esp?rant que ce soit clair pour toi !
>>
>> Denis Laventure
>> Universit? du Qu?bec ? Chicoutimi
>>
>>
>>
>> De : [email protected]
>> [mailto:[email protected]] De la part de Rob Morin
>> Envoy? : 27 janvier 2016 20:12
>> ? : [email protected]
>> Objet : ISC-dhcp subnet limit?
>>
>> Hello all, my first post here, so please be gentle J
>>
>> I have inherited 2 dhcp servers, one primary(dhcp-1) & one secondary(dhcp-2)
>> running isc-dhcpd-4.2.4 on Ubuntu 14.0(Trusty)
>>
>> We are having a few issues, and I cannot seem to figure out whats going on.
>> I have a few questions, maybe someone can help me with.
>>
>> Is there a max limit to how many subnets can be used in the pools? As
>> currently we are using just over 6000 subnets
>> Currently our secondary dhcp-server is always in recovery mode, not sure why?
>> Does it matter if a DISCOVER comes in on eth1 but OFFER goes out on eth0?
>>
>> My primary server /etc/dhcpd.conf file
>>
>> authoritative;
>> log-facility local7;
>> option domain-name "dyn";
>> option domain-name-servers 172.30.64.210, 172.30.64.220;
>> default-lease-time 1200;
>> max-lease-time 3600; # 1h
>> include "/etc/dhcp/dhcpd_pools.conf";
>> # Include the primary configuration
>> include "/etc/dhcp/dhcpd_primary.conf";
>>
>>
>> /etc/dhcp/dhcpd_primary has the following
>> ## PRIMARY
>> failover peer "tdl-dhcp-failover" {
>> primary; # declare this to be the primary server
>> address 172.30.128.9;
>> port 647;
>> peer address 172.30.128.10;
>> peer port 647;
>> max-response-delay 30;
>> max-unacked-updates 10;
>> load balance max seconds 3;
>> mclt 1800;
>> split 128;
>> }
>>
>> Exert from dhcpd_pools file, starts like this?.
>>
>> subnet 10.32.0.0 netmask 255.255.255.0 {
>> option routers 10.32.0.1;
>> pool {
>> failover peer "dhcp-failover";
>> range 10.32.0.5 10.32.0.254;
>> }
>> }
>>
>> And finishes like this, with all the subnets in between?
>>
>> subnet 10.57.255.0 netmask 255.255.255.0 {
>> option routers 10.57.255.1;
>> pool {
>> failover peer "dhcp-failover";
>> range 10.57.255.5 10.57.255.254;
>> }
>> }
>>
>>
>> Example Exert from logs on both serves of a client that could not get an IP
>>
>> from dhcp-1
>> Jan 27 18:30:31 dhcp-1 dhcpd: DHCPDISCOVER from fc:e9:98:bc:a8:7b (iPhone)
>> via 10.50.170.1
>> Jan 27 18:30:31 dhcp-1 dhcpd: DHCPOFFER on 10.50.170.93 to fc:e9:98:bc:a8:7b
>> (iPhone) via 10.50.170.1
>>
>> from dhcp-2
>> Jan 27 18:53:55 dhcp-2 dhcpd: DHCPDISCOVER from fc:e9:98:bc:a8:7b via
>> 10.50.170.1: peer holds all free leases
>> Jan 27 18:54:04 dhcp-2 dhcpd: DHCPDISCOVER from fc:e9:98:bc:a8:7b via
>> 10.50.170.1: peer holds all free leases
>>
>> Never see the ACK.
>>
>> Any suggestion would be greatly appreciated.. :
>>
>> Thanks?
>>
>> Rob
>> Montreal Canada
>>
>>
>>
>> _______________________________________________
>> dhcp-users mailing list
>> [email protected]
>> https://lists.isc.org/mailman/listinfo/dhcp-users
>
> _______________________________________________
> dhcp-users mailing list
> [email protected]
> https://lists.isc.org/mailman/listinfo/dhcp-users
-------------- next part --------------
An HTML attachment was scrubbed...
URL:
<https://lists.isc.org/pipermail/dhcp-users/attachments/20160131/776a4753/attachment.html>
------------------------------
_______________________________________________
dhcp-users mailing list
[email protected]
https://lists.isc.org/mailman/listinfo/dhcp-users
End of dhcp-users Digest, Vol 88, Issue 1
*****************************************
