[Dnsmasq-discuss] 53 Bad bootp tag size

Thu Aug 14 18:16:59 BST 2008

B. Cook wrote:
> Hello All,
> 
> Since moving to dnsmasq for all our dhcp 'needs' things have been quite
> reliable and predictiable.. we have much more control over things than we
> did in isc..
> 
> It seems we get this error on some Jetdirects.. and I am not sure why.
> 
> This one at the moment is on a J3113A (G.08.49 - latest rev and EOL'd) the
> other time it was on a 170X.
> 
> Here is some debug:
> Aug 14 11:41:32 core dnsmasq[26613]: DHCP packet: transaction-id is 236322816
> Aug 14 11:41:32 core dnsmasq[26613]: Available DHCP range: 10.20.18.2 --
> 10.20.19.254
> Aug 14 11:41:32 core dnsmasq[26613]: Vendor class: Hewlett-Packard JetDirect
> Aug 14 11:41:32 core dnsmasq[26613]: DHCPDISCOVER(em0) 00:10:83:55:85:c2
> Aug 14 11:41:32 core dnsmasq[26613]: DHCPOFFER(em0) 10.20.18.56
> 00:10:83:55:85:c2
> Aug 14 11:41:32 core dnsmasq[26613]: requested options: 1:netmask,
> 3:router, 7:log-server, 44:netbios-ns,
> Aug 14 11:41:32 core dnsmasq[26613]: requested options: 51:lease-time,
> 54:server-identifier, 58:T1,
> Aug 14 11:41:32 core dnsmasq[26613]: requested options: 59:T2,
> 12:hostname, 15:domain-name, 144,
> Aug 14 11:41:32 core dnsmasq[26613]: requested options: 18:extension-path
> Aug 14 11:41:32 core dnsmasq[26613]: tags: cli, cli, known
> Aug 14 11:41:32 core dnsmasq[26613]: sent size:  1 option: 53:message-type
>  02
> Aug 14 11:41:32 core dnsmasq[26613]: sent size:  4 option:
> 54:server-identifier  0a:14:00:10
> Aug 14 11:41:32 core dnsmasq[26613]: sent size:  4 option: 51:lease-time 
> 00:00:38:40
> Aug 14 11:41:32 core dnsmasq[26613]: sent size:  4 option: 58:T1  00:00:1c:20
> Aug 14 11:41:32 core dnsmasq[26613]: sent size:  4 option: 59:T2  00:00:31:38
> Aug 14 11:41:32 core dnsmasq[26613]: sent size:  4 option:  1:netmask 
> ff:ff:fe:00
> Aug 14 11:41:32 core dnsmasq[26613]: sent size:  4 option: 28:broadcast 
> 0a:14:13:ff
> Aug 14 11:41:32 core dnsmasq[26613]: sent size:  8 option: 15:domain-name 
> 63:6c:69:2e:70:63:73:64
> Aug 14 11:41:32 core dnsmasq[26613]: sent size:  0 option: 44:netbios-ns
> Aug 14 11:41:32 core dnsmasq[26613]: sent size:  4 option:  3:router 
> 0a:14:12:01
> 
> doing a grep -i bootp on my dnsmasq.log I find things like this:
> 
> Aug 14 11:32:52 core dnsmasq[26613]: cannot send DHCP/BOOTP option 6: no
> space left in packet
> Aug 14 11:32:52 core dnsmasq[26613]: BOOTP(em0) 10.20.18.56 00:10:83:55:85:c2
> Aug 14 11:32:52 core dnsmasq[26613]: tags: cli, bootp, cli, known
> Aug 14 11:33:20 core dnsmasq[26613]: BOOTP(em0) 00:11:43:91:f9:1c disabled
> Aug 14 11:34:23 core dnsmasq[26613]: BOOTP(em0) 00:11:43:91:f9:1c disabled
> Aug 14 11:35:25 core dnsmasq[26613]: BOOTP(em0) 00:11:43:91:f9:1c disabled
> Aug 14 11:36:28 core dnsmasq[26613]: BOOTP(em0) 00:11:43:91:f9:1c disabled
> Aug 14 11:37:30 core dnsmasq[26613]: BOOTP(em0) 00:11:43:91:f9:1c disabled
> 
> Not sure what I am missing.. but this will be the second Jetdirect that I
> will have to hardcode an IP address.. (fear..)
> 
> option 6 is dns-server
> here is what I have:
> 
>  grep dns-server dnsmasq.*.dhcp
> dnsmasq.cli.dhcp:dhcp-option=cli,option:dns-server,0.0.0.0          # DNS
> dnsmasq.kri.dhcp:dhcp-option=kri,option:dns-server,0.0.0.0          # DNS
> dnsmasq.phs.dhcp:dhcp-option=phs,option:dns-server,0.0.0.0          # DNS
> dnsmasq.smi.dhcp:dhcp-option=smi,option:dns-server,0.0.0.0          # DNS
> dnsmasq.war.dhcp:dhcp-option=war,option:dns-server,0.0.0.0          # DNS
> 
> I also tried making a global dns-server entry as well.. seems to be the
> same error..
> 
> looking up that other bootp mac it seems to be something 'Dell' related..
> I'll look into that..
> 
> I restarted dnsmasq and the printer and this is what is happening now..
> 
> dnsmasq --version
> Dnsmasq version 2.46test4  Copyright (C) 2000-2008 Simon Kelley
> Compile time options no-IPv6 GNU-getopt BSD-bridge no-DBus no-I18N TFTP
> 
> Aug 14 12:16:12 core dnsmasq[24692]: DHCP packet: transaction-id is 687996928
> Aug 14 12:16:12 core dnsmasq[24692]: Available DHCP range: 10.20.18.2 --
> 10.20.19.254
> Aug 14 12:16:12 core dnsmasq[24692]: Vendor class: Hewlett-Packard JetDirect
> Aug 14 12:16:12 core dnsmasq[24692]: DHCPDISCOVER(em0) 192.0.0.192
> 00:10:83:55:85:c2
> Aug 14 12:16:12 core dnsmasq[24692]: DHCPOFFER(em0) 10.20.18.56
> 00:10:83:55:85:c2
> Aug 14 12:16:12 core dnsmasq[24692]: requested options: 1:netmask,
> 3:router, 7:log-server, 44:netbios-ns,
> Aug 14 12:16:12 core dnsmasq[24692]: requested options: 51:lease-time,
> 54:server-identifier, 58:T1,
> Aug 14 12:16:12 core dnsmasq[24692]: requested options: 59:T2,
> 12:hostname, 15:domain-name, 144,
> Aug 14 12:16:12 core dnsmasq[24692]: requested options: 18:extension-path
> Aug 14 12:16:12 core dnsmasq[24692]: tags: cli, cli, known
> Aug 14 12:16:12 core dnsmasq[24692]: sent size:  1 option: 53:message-type
>  02
> Aug 14 12:16:12 core dnsmasq[24692]: sent size:  4 option:
> 54:server-identifier  0a:14:00:10
> Aug 14 12:16:12 core dnsmasq[24692]: sent size:  4 option: 51:lease-time 
> 00:00:38:40
> Aug 14 12:16:12 core dnsmasq[24692]: sent size:  4 option: 58:T1  00:00:1c:20
> Aug 14 12:16:12 core dnsmasq[24692]: sent size:  4 option: 59:T2  00:00:31:38
> Aug 14 12:16:12 core dnsmasq[24692]: sent size:  4 option:  1:netmask 
> ff:ff:fe:00
> Aug 14 12:16:12 core dnsmasq[24692]: sent size:  4 option: 28:broadcast 
> 0a:14:13:ff
> Aug 14 12:16:12 core dnsmasq[24692]: sent size:  8 option: 15:domain-name 
> 63:6c:69:2e:70:63:73:64
> Aug 14 12:16:12 core dnsmasq[24692]: sent size:  0 option: 44:netbios-ns
> Aug 14 12:16:12 core dnsmasq[24692]: sent size:  4 option:  3:router 
> 0a:14:12:01
> 
> Here are the dhcp-options I have set:
> (these are global)
> dnsmasq.phs.dhcp:dhcp-option=option:netbios-nodetype,2
> dnsmasq.phs.dhcp:dhcp-option=option:netbios-scope
> 
> dnsmasq.cli.dhcp:dhcp-option=cli,option:router,10.20.18.1
> dnsmasq.cli.dhcp:dhcp-option=cli,option:dns-server,0.0.0.0
> dnsmasq.cli.dhcp:dhcp-option=cli,option:netbios-ns      
> dnsmasq.cli.dhcp:dhcp-option=cli,option:netbios-dd
> 
> dnsmasq.kri.dhcp:dhcp-option=kri,option:router,10.20.4.1
> dnsmasq.kri.dhcp:dhcp-option=kri,option:dns-server,0.0.0.0
> dnsmasq.kri.dhcp:dhcp-option=kri,option:netbios-ns   
> dnsmasq.kri.dhcp:dhcp-option=kri,option:netbios-dd
> 
> dnsmasq.phs.dhcp:dhcp-option=net:phs,option:router,10.20.0.1  
> dnsmasq.phs.dhcp:dhcp-option=phs,option:dns-server,0.0.0.0
> dnsmasq.phs.dhcp:dhcp-option=net:phs,option:netbios-ns,10.20.0.230     
> dnsmasq.phs.dhcp:dhcp-option=net:phs,option:netbios-dd,10.20.0.230
> 
> dnsmasq.smi.dhcp:dhcp-option=smi,option:router,10.20.6.1
> dnsmasq.smi.dhcp:dhcp-option=smi,option:dns-server,0.0.0.0
> dnsmasq.smi.dhcp:dhcp-option=smi,option:netbios-ns   
> dnsmasq.smi.dhcp:dhcp-option=smi,option:netbios-dd
> 
> dnsmasq.war.dhcp:dhcp-option=war,option:router,10.20.14.1
> dnsmasq.war.dhcp:dhcp-option=war,option:dns-server,0.0.0.0
> dnsmasq.war.dhcp:dhcp-option=war,option:netbios-ns   
> dnsmasq.war.dhcp:dhcp-option=war,option:netbios-dd
> 
> Any ideas?
> 

Probably completely benign. It looks like the JetDirect is trying BOOTP 
first (at 11:32:52 ) and then moving on to DHCP (at 11:41:32).

The BOOTP request gets truncated options because a BOOTP packet has only 
64 bytes available for options. It looks like that means that needed 
information is left out and the printer tries again with DHCP - which 
works fine. After your restart, the printer seems to stick with DHCP and 
everything is OK.

To avoid the problem, you could see if it's possible to configure the 
printer to not use BOOTP somehow, or add something like

dhcp-mac=wackyjetdirect,00:10:83:55:85:c2
dhcp-ignore=wackyjetdirect,bootp

Which tells dnsmasq to ignore BOOTP requests from that MAC, rather than 
sending a truncated answer. If you have no use for BOOTP, just do

dhcp-ignore=bootp

HTH

Simon.