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Why would addresses from a range not appear in the lease file

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Friesen, Don MTIC:EX

Why would addresses from a range not appear in the lease file

We included a new range in a secondary subnet, and only half the addresses appeared in the dhcpd.leases file.

shared-network "10_10_184_192" {

subnet 10.10.184.192 netmask 255.255.255.224 {

option routers 10.10.184.193;

pool {

deny dynamic bootp clients;

failover peer "PoBCdhcp";

default-lease-time 1382400;

option domain-name "hpr.for";

option domain-name-servers 10.10.208.196,10.20.202.100;

max-lease-time 1382400;

option ntp-servers 10.10.26.35, 10.20.250.35, 10.30.23.78;

range 10.10.184.202 10.10.184.215;

range 10.10.184.217;

range 10.10.184.219;

range 10.10.184.222;

}

subnet 10.10.200.224 netmask 255.255.255.224 {

option routers 10.10.200.225;

pool {

deny dynamic bootp clients;

failover peer "PoBCdhcp";

default-lease-time 1382400;

option domain-name "hpr.for” ;

option domain-name-servers 10.10.208.196,10.20.202.100;

max-lease-time 1382400;

option ntp-servers 10.10.26.35, 10.20.250.35, 10.30.23.78;

range 10.10.200.226 10.10.200.253;

}

Only addresses 1010.200.239 through 10.10.200.253 appear in the dhcpd.leases file, the others in the secondary range, 10.10.200.226 through 10.10.200.238 do not.

What would cause this?

Don Friesen

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Niall O'Reilly

Re: Why would addresses from a range not appear in the lease file

On 22 Apr 2016, at 21:55, Friesen, Don MTIC:EX wrote:

> We included a new range in a secondary subnet, and only half the
> addresses appeared in the dhcpd.leases file.

Could it be that the leases which haven't shown up in dhcpd.leases
simply
haven't been assigned yet?

Best regards,
Niall O'Reilly
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Patrick Trapp

Re: Why would addresses from a range not appear in the lease file

In reply to this post by Friesen, Don MTIC:EX

Do both members of the failover pair show the same half of the new pool? I thought they were supposed to split it and assign from their half as long as their partner was up and running.

Patrick

On Apr 22, 2016, at 3:55 PM, Friesen, Don MTIC:EX <[hidden email]> wrote:

   We included a new range in a secondary subnet, and only half the addresses appeared in the dhcpd.leases file.

shared-network "10_10_184_192" {

   subnet 10.10.184.192 netmask 255.255.255.224 {

      option routers 10.10.184.193;

      pool {

         deny dynamic bootp clients;

         failover peer "PoBCdhcp";

         default-lease-time 1382400;

      option domain-name "hpr.for";

      option domain-name-servers 10.10.208.196,10.20.202.100;

      max-lease-time 1382400;

      option ntp-servers 10.10.26.35, 10.20.250.35, 10.30.23.78;

         range 10.10.184.202 10.10.184.215;

         range 10.10.184.217;

         range 10.10.184.219;

         range 10.10.184.222;

      }

   }

subnet 10.10.200.224 netmask 255.255.255.224 {

      option routers 10.10.200.225;

      pool {

         deny dynamic bootp clients;

         failover peer "PoBCdhcp";

         default-lease-time 1382400;

      option domain-name "hpr.for” ;

      option domain-name-servers 10.10.208.196,10.20.202.100;

      max-lease-time 1382400;

      option ntp-servers 10.10.26.35, 10.20.250.35, 10.30.23.78;

         range 10.10.200.226 10.10.200.253;

      }

   }

}

   Only addresses 1010.200.239 through 10.10.200.253 appear in the dhcpd.leases file, the others in the secondary range, 10.10.200.226 through 10.10.200.238 do not.

   What would cause this?

Don Friesen

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Niall O'Reilly

Re: Why would addresses from a range not appear in the lease file

In reply to this post by Niall O'Reilly

On 23 Apr 2016, at 11:44, Niall O'Reilly wrote:

> On 22 Apr 2016, at 21:55, Friesen, Don MTIC:EX wrote:
>
>> We included a new range in a secondary subnet, and only half the
>> addresses appeared in the dhcpd.leases file.
>
> Could it be that the leases which haven't shown up in dhcpd.leases
> simply
> haven't been assigned yet?

I'm sorry. I misread the question. With failover mode, I too would
find what you describe surprising.
Best regards,
Niall O'Reilly
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Niall O'Reilly

Re: Why would addresses from a range not appear in the lease file

In reply to this post by Friesen, Don MTIC:EX

On 22 Apr 2016, at 21:55, Friesen, Don MTIC:EX wrote:

> Only addresses 1010.200.239 through 10.10.200.253 appear in the
> dhcpd.leases file, the others in the secondary range, 10.10.200.226
> through 10.10.200.238 do not.
>
> What would cause this?

Do the configurations for the shared network in question match on
both servers?
And the leases.dhcpd files?
Has each server been restarted to load the new configuration?
Are there any unexpected log messages referring to communication
between the servers?

I hope this helps.

Best regards,
Niall O'Reilly
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Friesen, Don MTIC:EX

RE: Why would addresses from a range not appear in the lease file

>> Only addresses 1010.200.239 through 10.10.200.253 appear in the
>> dhcpd.leases file, the others in the secondary range, 10.10.200.226
>> through 10.10.200.238 do not.
>>
>> What would cause this?
>
> Do the configurations for the shared network in question match on both servers?

The segments of the config that describe the shared networks are generated on another server and shared to the two equally.

> And the leases.dhcpd files?

These same IPs are in each servers lease files.

> Has each server been restarted to load the new configuration?

Yes. When a configuration change happens, the script that builds the files forces a restart.

> Are there any unexpected log messages referring to communication between the servers?

No unexpected messages were seen in the log files.

Over the weekend, 3 addresses that previously did not have lease records now do have lease records.

10.10.200.225 Gateway fjorv042.lan.net.gov.bc.ca
10.10.200.226 Dynamic
10.10.200.227 Dynamic
10.10.200.228 Dynamic
10.10.200.229 Dynamic
10.10.200.230 Dynamic
10.10.200.231 Dynamic
10.10.200.232 Dynamic
10.10.200.233 Dynamic
10.10.200.234 Dynamic
10.10.200.235 Dynamic
10.10.200.236 Dynamic
10.10.200.237 Dynamic Dynamic 54EE750 <-- not in leases file previously
10.10.200.238 Dynamic Dynamic 54EE754 <-- not in leases file previously
10.10.200.239 Dynamic Dynamic 3C18A0
10.10.200.240 Dynamic Dynamic 3C970E
10.10.200.241 Dynamic Dynamic
10.10.200.242 Dynamic Dynamic 54EE75
10.10.200.243 Dynamic Dynamic
10.10.200.244 Dynamic Dynamic
10.10.200.245 Dynamic Dynamic
10.10.200.246 Dynamic Dynamic
10.10.200.247 Dynamic Dynamic
10.10.200.248 Dynamic Dynamic
10.10.200.249 Dynamic Dynamic
10.10.200.250 Dynamic Dynamic
10.10.200.251 Dynamic Dynamic
10.10.200.252 Dynamic Dynamic
10.10.200.253 Dynamic Dynamic
10.10.200.254 ---->> Available

The first column of "Dynamic" is the range, the second is what is seen in the leases file. My understanding was that with failover all IPs appear in the leases file, active or not.

If it wasn't for the 239 address, I might have thought the mask was wrong initially. But now two additional addresses have appeared in the dhcpd.leases file, and been assigned out. The servers must know about them internally, they are just not being recorded in the dhcpd.leases file.

>
> I hope this helps.

It helps to know I'm not crazy for thinking that failover should be recording the available IPs as well as those taken.

>
> Best regards,
> Niall O'Reilly

Don Friesen
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Simon Hobson-2

Re: Why would addresses from a range not appear in the lease file

"Friesen, Don MTIC:EX" <[hidden email]> wrote:

> My understanding was that with failover all IPs appear in the leases file, active or not.

No. AIUI a lease does not appear in the file until the address has been used. Internally, every address in a range is present in the hash tables, but they aren't written out to disk until the lease info is "no longer blank".

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Simon Hobson

Re: Why would addresses from a range not appear in the lease file

In reply to this post by Friesen, Don MTIC:EX

Friesen, Don MTIC:EX

RE: Why would addresses from a range not appear in the lease file

>> My understanding was that with failover all IPs appear in the leases file, active or not.
>
>No. AIUI a lease does not appear in the file until the address has been used. Internally, every address in a range is present in the hash tables, but they aren't written out to disk until the lease info is "no longer blank".

With failover... does primary record the leases assigned to the secondary in the leases file as vacant... "backup", and those missing are assigned to the primary? I just noticed that all the vacant leases in the dhcpd.leases file are tagged 'backup', which would be the delegation to the secondary peer, right?

lease 10.10.200.248 {
starts 5 2016/04/22 19:40:29;
tstp 5 2016/04/22 19:40:29;
tsfp 5 2016/04/22 19:40:29;
atsfp 5 2016/04/22 19:40:29;
binding state backup;
}

Don Friesen
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