[Dnsmasq-discuss] static lease issues?

[Kevin Darbyshire-Bryant]

Hi Simon, Hi List,

I’m hearing rumblings from the openwrt community that something isn’t right with static leases. The behaviour manifests itself as the statically assigned host being unable to renew its lease. e.g.

-this is okay
Nov 4 15:29:29 192.168.0.254 dnsmasq-dhcp[2378]: 424644159 available DHCP range: 192.168.0.100 -- 192.168.0.199
Nov 4 15:29:29 192.168.0.254 dnsmasq-dhcp[2378]: 424644159 client provides name: sylvester
Nov 4 15:29:29 192.168.0.254 dnsmasq-dhcp[2378]: 424644159 DHCPDISCOVER(eth0.54) 00:11:22:33:44:55
Nov 4 15:29:29 192.168.0.254 dnsmasq-dhcp[2378]: 424644159 tags: lan, known, eth0.54
Nov 4 15:29:29 192.168.0.254 dnsmasq-dhcp[2378]: 424644159 DHCPOFFER(eth0.54) 192.168.0.12 00:11:22:33:44:55
-but later

Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 available DHCP range: 192.168.0.100 -- 192.168.0.199
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 client provides name: sylvester
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 DHCPREQUEST(eth0.54) 192.168.0.12 00:11:22:33:44:55
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 DHCPNAK(eth0.54) 192.168.0.12 00:11:22:33:44:55 address not available
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 broadcast response
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 sent size: 1 option: 53 message-type 6
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 sent size: 4 option: 54 server-identifier 192.168.0.254
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 sent size: 21 option: 56 message 61:64:64:72:65:73:73:20:6e:6f:74:20:61:76...
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 1321333264 available DHCP range: 192.168.0.100 -- 192.168.0.199
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 1321333264 client provides name: sylvester
Nov 4 15:52:36 192.168.0.254 dnsmasq-dhcp[2378]: 1321333264 DHCPDISCOVER(eth0.54) 00:11:22:33:44:55
Nov 4 15:52:36 192.168.0.254 dnsmasq-dhcp[2378]: 1321333264 tags: lan, known-othernet, eth0.54
Nov 4 15:52:36 192.168.0.254 dnsmasq-dhcp[2378]: 1321333264 DHCPOFFER(eth0.54) 192.168.0.190 00:11:22:33:44:55

I have yet to see this behaviour personally, so I’m putting this out there as a) anyone else b) any ideas on debugging?


Cheers,

Kevin D-B

012C ACB2 28C6 C53E 9775 9123 B3A2 389B 9DE2 334A

[Geert Stappers]

Executive summary: email has been seen

Post by Kevin Darbyshire-Bryant
Hi Simon, Hi List,

Hello List,

Post by Kevin Darbyshire-Bryant
I???m hearing rumblings from the openwrt community that something
isn???t right with static leases.

Please pursuit it further

Post by Kevin Darbyshire-Bryant
The behaviour manifests itself as the statically assigned host being unable to renew its lease. e.g.
-this is okay

Please dont take it for granted ...

Post by Kevin Darbyshire-Bryant
Nov 4 15:29:29 192.168.0.254 dnsmasq-dhcp[2378]: 424644159 available DHCP range: 192.168.0.100 -- 192.168.0.199
Nov 4 15:29:29 192.168.0.254 dnsmasq-dhcp[2378]: 424644159 client provides name: sylvester
Nov 4 15:29:29 192.168.0.254 dnsmasq-dhcp[2378]: 424644159 DHCPDISCOVER(eth0.54) 00:11:22:33:44:55
Nov 4 15:29:29 192.168.0.254 dnsmasq-dhcp[2378]: 424644159 tags: lan, known, eth0.54
Nov 4 15:29:29 192.168.0.254 dnsmasq-dhcp[2378]: 424644159 DHCPOFFER(eth0.54) 192.168.0.12 00:11:22:33:44:55

Here I'm missing the logging of DHCPREQUEST and DHCPACK

Post by Kevin Darbyshire-Bryant
-but later
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 available DHCP range: 192.168.0.100 -- 192.168.0.199
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 client provides name: sylvester
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 DHCPREQUEST(eth0.54) 192.168.0.12 00:11:22:33:44:55
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 DHCPNAK(eth0.54) 192.168.0.12 00:11:22:33:44:55 address not available
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 broadcast response
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 sent size: 1 option: 53 message-type 6
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 sent size: 4 option: 54 server-identifier 192.168.0.254
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 sent size: 21 option: 56 message 61:64:64:72:65:73:73:20:6e:6f:74:20:61:76...

Option 56 is DHCP Error Message

message 61:64:64:72:65:73:73:20:6e:6f:74:20:61:76...
ASCII a d d r e s s n o t a v

Post by Kevin Darbyshire-Bryant
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 1321333264 available DHCP range: 192.168.0.100 -- 192.168.0.199
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 1321333264 client provides name: sylvester

Gap of four seconds

Post by Kevin Darbyshire-Bryant
Nov 4 15:52:36 192.168.0.254 dnsmasq-dhcp[2378]: 1321333264 DHCPDISCOVER(eth0.54) 00:11:22:33:44:55
Nov 4 15:52:36 192.168.0.254 dnsmasq-dhcp[2378]: 1321333264 tags: lan, known-othernet, eth0.54
Nov 4 15:52:36 192.168.0.254 dnsmasq-dhcp[2378]: 1321333264 DHCPOFFER(eth0.54) 192.168.0.190 00:11:22:33:44:55

Those three log entries are the same as Nov 4 15:29:29

Post by Kevin Darbyshire-Bryant
I have yet to see this behaviour personally, so I???m putting this out there as
a) anyone else
b) any ideas on debugging?

Debugging idea: Get involvement of the initial reporter.


The above "anyone else seen this?" is the real problem. Which is
not understanding the problem.

The P in DHCP stands for Protocol. It is between server and client.

So please take some time to tell more about the client
plus how they are configured and connected.



Groeten
Geert Stappers

[Simon Kelley]

Post by Kevin Darbyshire-Bryant
Hi Simon, Hi List,
I’m hearing rumblings from the openwrt community that something isn’t right with static leases. The behaviour manifests itself as the statically assigned host being unable to renew its lease. e.g.
-this is okay
Nov 4 15:29:29 192.168.0.254 dnsmasq-dhcp[2378]: 424644159 available DHCP range: 192.168.0.100 -- 192.168.0.199
Nov 4 15:29:29 192.168.0.254 dnsmasq-dhcp[2378]: 424644159 client provides name: sylvester
Nov 4 15:29:29 192.168.0.254 dnsmasq-dhcp[2378]: 424644159 DHCPDISCOVER(eth0.54) 00:11:22:33:44:55
Nov 4 15:29:29 192.168.0.254 dnsmasq-dhcp[2378]: 424644159 tags: lan, known, eth0.54
Nov 4 15:29:29 192.168.0.254 dnsmasq-dhcp[2378]: 424644159 DHCPOFFER(eth0.54) 192.168.0.12 00:11:22:33:44:55
-but later
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 available DHCP range: 192.168.0.100 -- 192.168.0.199
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 client provides name: sylvester
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 DHCPREQUEST(eth0.54) 192.168.0.12 00:11:22:33:44:55
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 DHCPNAK(eth0.54) 192.168.0.12 00:11:22:33:44:55 address not available
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 broadcast response
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 sent size: 1 option: 53 message-type 6
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 sent size: 4 option: 54 server-identifier 192.168.0.254
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 53015875 sent size: 21 option: 56 message 61:64:64:72:65:73:73:20:6e:6f:74:20:61:76...
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 1321333264 available DHCP range: 192.168.0.100 -- 192.168.0.199
Nov 4 15:52:32 192.168.0.254 dnsmasq-dhcp[2378]: 1321333264 client provides name: sylvester
Nov 4 15:52:36 192.168.0.254 dnsmasq-dhcp[2378]: 1321333264 DHCPDISCOVER(eth0.54) 00:11:22:33:44:55
Nov 4 15:52:36 192.168.0.254 dnsmasq-dhcp[2378]: 1321333264 tags: lan, known-othernet, eth0.54
Nov 4 15:52:36 192.168.0.254 dnsmasq-dhcp[2378]: 1321333264 DHCPOFFER(eth0.54) 192.168.0.190 00:11:22:33:44:55
I have yet to see this behaviour personally, so I’m putting this out there as a) anyone else b) any ideas on debugging?

Look at the tags on the first and second DHCPDISCOVERs. The first one is
in "known" and the second is "known-othernet".

"known" means that the host has a dhcp-host or similar configuration
which provides an address, and the address in in scope for the network
it's talking from. "known-othernet" means the same, but the the address
is NOT in scope.

That probably explains the DHCPNAK too.

The question is "what's changed". difficult to tell. Maybe the netmask
on the interface?


Cheers,

Simon.

[Kevin Darbyshire-Bryant]

Post by Simon Kelley
Look at the tags on the first and second DHCPDISCOVERs. The first one is
in "known" and the second is "known-othernet".
"known" means that the host has a dhcp-host or similar configuration
which provides an address, and the address in in scope for the network
it's talking from. "known-othernet" means the same, but the the address
is NOT in scope.
That probably explains the DHCPNAK too.
The question is "what's changed". difficult to tell. Maybe the netmask
on the interface?

Thanks Simon. I noticed the ‘othernet’ tag but didn’t quite understand why it would be applied. Have asked person affected for more clues :-)


Cheers,

Kevin D-B

012C ACB2 28C6 C53E 9775 9123 B3A2 389B 9DE2 334A